100%. This is the reason I watch James's content. Other channels might do tests and experiment. No one else is going to have not one, but two, frankenmoka pots built. And then proceed to do a couple weeks worth of testing and data collection. I come to James Hoffmann for coffee science
As a scientist in basic research, I’m flabbergasted by your approach! From designing the experiment, building the equipment, methodical data collection and documentation to the critical analysis - just awesome!
Arguably the best video you’ve ever made. As an Italian guy I feel flattered that you decided to dedicate your attention to this brewer. It’s really frustrating the process of making a good brew out of this thing. I’m looking forward to watch your next video in this series and I’m sure it’ll give me a huge help! THANK YOU
I'm Italian as well and the whole family and Nonna included uses this Moka. I've never imagined it would be so tricky. I just use lavazza oro up until the top of the filter (a little bit before that actually), room temperature water at the limit. No induction, gas. Low heat. Always works fine... I believe using the plate is wrong. They designed a Mock specially for induction also if you check in their website. :)
@@jonmahashintina Well then you don't know much. Nobody that I know does that. We don't clean with soap. But we vociferously clean it to make it like new. They usually outlast you.
Honestly, this amount of science behind the Moka Pot in terms of the coffee community producing the results is long overdue, and very much appreciated coming from you. Thank you so much for your dedication to the data!
@@pamusso1466 You seem to have misunderstood how a Moka pot works - the water is pushed through the tube by steam pressure, it doesn't go through the coffee while it's steam.
As an Italian I'm very grateful to be properly schooled on moka. Thx so much for your service to our culture. P.s. I still can't have coffee at my parents because it sucks badly, but my home brew is now top notch 👌
I'm sorry. That really sucks. As they get older their taste buds are less sensitive and they will just feel the bitterness of the coffee rather than actually tasting the sweet, fruity, and floral notes. I had a friend who's dad was in his 80s and he used a stove top percolator and just let that thing sit for so long. Bitter mud was produced. That stuff would blow out your intestines! May you have a great day and many Happy brews!
@kg8568 😂 my uncle was in the military and his wife clean their coffee machine and he had a complete freaking meltdown because she ruined the flavor. He calls the build-up of oils and stuff seasoning instead of realizing once you leave it sit for a couple weeks when you're on vacation there just Rancid coffee oils. He buys cheap coffee in bulk and the darkest roast so I got an inkling what you dealt with but I've never had to deal with super over percolated coffee except one time when I personally didn't know what I was doing and tried to make it for a holiday party haha... some of the older folks were fine with it but the rest of us were just like nope or made it mostly sugar (like 7 tsp sugar in my mug, half full of half and half 😳
This was great. It explains why I started grinding finer when I was living at altitude (12,000 ft / 3650 m), where water boiled at 190F (87c) - meaning impossible to make a decent French press - but a mocha pot with the finer grind worked -- forced pressure up, and therefore temperature. It also explains why that part of the world is not a coffee culture - you couldn't get the water hot enough to do a decent extraction -- unless you had pressure.
James be like: "I'm currently inside of a pressure chamber at 12k ft above sea level. In this video I will show you how to make coffe in a french press, aeropress, mocha pot and yes a bripe. I am also not going to keep this pressure chamber as it will go to one of my patreons." Follow-up video will be him in scuba gear, brewing coffee under water.
The aluminum vs steel test was very interesting and also makes sense to me. Basically answers the question of why we have clad cookware. Aluminum heats very evenly but retains heat poorly, while steel retains heat well but heats uneven. When you sandwich aluminum between steel (ie, cladding it) you get the best of both: even heating and good retention. Now someone just needs to make a clad moka pot!
Aluminium retains heat well, but needs to be a bit thicker to do so successfully. The reason why aluminium is sandwiched in clad cookware is because it is highly reactive to food AND cleaning detergents. I have a thick Demeyere Proline pan that retains heat as well as my cast iron pans.
@@lgolem09l I think that aluminum conducts heat well, so it distributes well across the metal, but it retains heat poorly, which is why if you move aluminum away from a heat source it cools down rapidly. Steel conducts heat poorly, but retains it well. This observation tells me that conduction and retention are related; if it conducts well, it retains poorly and vice versa.
@@Taku071090 aluminium has almost twice as much heat capacity than carbon steel, but that is per kg. Carbon steel is a lot more dense though, so at the same thickness, it wins because of that. A thick aluminium pan can have both advantages, that's what I use. Also, copper does well at both, even at low thickness.
We can't do an ironclad comparison (pun intended) of different alloys by just discussing singular elements. Yes pure aluminum is a better heat conductor than pure iron (it also dissipates heat faster), but Stainless Steel (Austenitics or "300 series") is comprised of 0.015% to 0.10% carbon, 16% to 21% chromium, 6% to 26% nickel, 0% to 7% molybdenum, with the remaining being iron of course. I've had some difficulty tracking down the grade/series of the aluminum moka pots used by Bialetti, but I did find one study that used an XRF Spectrometer on their sample and identified the bottom boiler to be comprised of 67.07% aluminum, the basket/filter to be 94.92% aluminum and upper chamber to be 78.51% aluminum; feel free to guess the grade/series being used... I'm SURE heat retention was taken into consideration when developing these products, but I believe the main reason Bialetti aluminum pots have thick casting is simply because aluminum is rather malleable. Have you ever tried crushing an empty steel can of green beans by hand? Its thickness is comparable to an aluminum can of soda, but the aluminum can is miles easier to crush. Who wants to use a pot that warps too easily? If I was going to sell aluminum cookware, I'd make the metal thick too. Keeping all that in mind, the earlier heat read of the stainless steel model is likely due to the upper chamber simply being so thin, after all it's steel, it doesn't need to be super thick to be sturdy.
There's something beautiful and very Hoffman about taking the Mokka pot, the epitome of simplicity and turning it into something that looks like it belongs on the ISS
Watched this video yesterday, dug my moka pot out of storage, and proceeded to make the best moka pot coffee of my life this morning... Thank you, James!
It's amazing the amount of effort James put into these "understanding" videos. I'm an owner of a moka pot, it's my main device to make coffee and this is super useful, can't wait to the next video.
One common recommendation I got when I had a moka pot was to put a bit of cold water in the top chamber to kind of regulate the temperature during brewing, so that once the coffee comes out, it doesn't hit overly hot metal. I had some encouraging, but mixed results with it, and I feel like it would be interesting to test with your, much more controlled setup.
yeah, I was gonna mention this one also. :) the reason for it, according to my friend at the time, was to control the temperature also as you said, but after watching this video it made me wonder if it also helps by diluting it a bit. it is a lot less water than suggested in the video for diluting it, but it should still increase the final amount for at least a "sip" I guess hahaha
Also, what about a few ice cubes? Edit: It works, I suppose! I set aside 40-50g of ice in a cup and dump them in my ("3 cup" bialetti) moka as soon as the brewing starts. I can't say for certain if it tastes better as I haven't felt like brewing two pots in a row but I do know that it's cooled down to a good drinking temp.
Ah, a mashup is obviously needed: “There are some four million different kinds of animals and plants in the world. Four million different solutions to the problems of staying alive. And another million solutions to the problems of brewing a delicious cup of coffee.”
I love that you said "ignorance is bliss" and I couldn't agree more! I love this nerdy videos despite me understanding almost nothing of it. I use a moka pot and for me is extremelly easy because I don't know all the little things about the coffee I'm drinking. Great video as always!
as italian, growing up with nerdy million dollar questions on all the variables to make moka coffee, I was surprized when you said about the aeropress "this is exciting because you can control so many variables and have competitions on how to make coffee". Now I see that all my waiting to see how crazy you can go with the moka was well worth it!!!! Thanks for the video!! (in my opinion this video alone should grant you italian citizenship if you do not have it already)
I love it! 😆 Here in Italy, the "sputtering" sound does mean Coffee time! And that's probably why Moka coffee sucks most of the time! Lots of learnings here! thanks! ✅
Somehow this has validated like 90% of my technique that I’ve developed through trial and error over the years and I am thoroughly pleased about that. Very excited to use all this next-level info that I otherwise wouldn’t have access to on my own to play around with things and tweak my technique to an even more ideal and repeatable brew. Thank you James!!
My Moka pot was extremely inconsistent until I lubricated the joint and the screw with vegetable oil (I used peanut; then of course the first(s) brews need be disposed of). This very simple yet effective trick I randomly found on the Internet after a lot of frustration and bad coffee made my pot not only work consistently, but also (and most surprisingly) almost fully stop the angry spluttering. Thanks to the lubrication there's virtually no pressure loss through the joints and coffee flows evenly throughout the brew until the end, where it gently and not angrily foams a bit and becomes lighter in color. It is at that point that I remove it from the stove and cool down the pressure chamber as indicated by James. I have the steel (induction) Bialetti, where I use medium-ground coffee, pour boiling water in the cold pressure chamber, and brew on a gas stove at quite a low flame (not the lowest though). Coffee is really good and balanced in this way.
I might not be understanding this correctly, but by "joint and the screw" do you mean the screw-thread that joins the upper and lower chambers together? If so, that thread is not intended to provide any seal at all - the seal is provided by the rubber gasket. Applying some lubricant to the gasket may allow a degraded gasket to seal better (temporarily) but replacing the gasket would be the best thing.
@@Rowlph77 Thanks for your reply! With joint I meant the sealing gasket indeed. With screw I meant the screw thread indeed. I know that this particular screw is not air tight, but lubrication really does help the whole thing work more consistently (I'm an engineer, I know a thing or two about screws ;-) ). Also, the gasket was new and the machine was inconsistent from day one, so it was not an issue of a degraded gasket, which indeed as you mention would need be replaced. In any case that's what I did and it works for me, so I was happy to share the tip :-).
@@ignaciopardo8963 Thanks - I'm going to try this tomorrow then! Although my gasket is not new, it's still in good condition. I just have ordinary vegetable oil to hand, will be interested to see if it stops/reduces the sputtering at the end.
I may give this a try. I have found I have had to torque the nuts off (the technical term, I believe) the thread to ensure a decent-sized extraction. So actually could a better gasket from different material save all of this hassle or can it not be saved without a tighter toleranced thread? N.B I also have one of the stainless versions
We just tried the suggestion of turning down the heat once the coffee starts flowing, and our volume output increased. Cool! We made our usual milk drinks. Then, because we had some extra coffee, we each took a taste of it straight. Wow! The flavor is wonderful, noticeably less bitter, and my husband was so impressed, he even said he could probably drink this coffee without milk. Obviously, we didn't want to waste our milk drinks, so we then drank those, but next time, I might try out a cortado-style drink instead of my usual "latte." Cheers!
So for your milk drink, add whipped cream on top. Then take that extra coffee and pour it over the whipped cream. Adds a lot of depth to the drink and the sweetness tamps the bitterness of the straight coffee so you really get the other notes.
@@kg-Whatthehelliseventhat Yes, we always use a bowl of cold water to dip the bottom of the Moka Pot into it (rather than go across the kitchen to the sink with a hot metal thing while our cats are rubbing all around our legs for attention and/or food).
What an incredible video. I changed a few things today: starting temperature (hot rather than cold), heating on a moderate heat and whipping the pot off when it sputters/running it under the cold tap. Wow -- *what* a smoother brew! And credit, as always, for chapter headings in the video. Another subscriber right here!
It really seems like THIS is the content you love making 😁 So much attention to detail, so much time invested, you can even hear the excitement and interest in your voice as you explain the real world effects of the data All this time, money, and resources dedicated to just helping people understand a coffee brewer, and even then you hold a raffle for a charity doing wonderful work... You're a coffee saint, James
This man is insane, and I love it! It’s literally physically exciting to watch a video of a guy doing all the stuff you wouldn’t/couldn’t ever do yourself, although you probably fantasize about all of this. Truly amazing.
Nice video James! I've been a thermal engineer for almost 40 years and you handled this testing well - very well. I'd give you an A+ grade! My only comment is that the radiative heating when you lift the Moka pot off the diffusion plate isn't has large as you think - because the emissivity of the Moka pot is very low. The diffusion plate may be low or high depending on material's surface finish (anodized aluminum is high, but a polished steel would be low). Likely what you are seeing is a reduced heat loss through the sides of the pot because of the hot air flow around the pot in the air, and also you are using the stored thermal energy in the Moka pot to continue the brewing process. Nonetheless, this was very well done - congrats!
WOW!!! This is actually groundbreaking research, I don't think at any other point in time has the Moca pot been studied as in depth as this!!!! Love it!!!!
One interesting upgrade to consider is Bialetti Brikka - it has additional valve to build up pressure and prevent brewing with colder water I think. It would be great to hear your thoughts about such upgrade.
When you talked about diffusion plates on a gas stove, it reminded me of a solution I had to making my moka coffee a few months ago. The gas stove I was using had grates too large to fit my tiny moka pot on it, so I had to place a frying pan on the heat, and then place my moka pot on top there. Maybe this could help you in the diffusion plates situation. A frying pot should be able to hold heat, though I don't know how it would compare to a diffusion plate. I can say that usually on a gas stove I find it difficult to make a good pot because of the high heat that even the low setting provides, and a frying pan helped with that.
I've had a mokapot for years, but i have an induction stove, so I've never tried it. Why didn't I think of using a frying pan??? I'll do it the first time tomorrow! I'm so excited!
@@Bulleht It works a charm. I've been using an original aluminium pot on induction for 7 years now using a thick bottom pan as a sacrificial heatdisperser. Now I've seen this vid I'm really going to experiment a bit :)
I Imagine something like a cast iron would do a similar thing too, with even more thermal mass to sort of "smooth out" the heat like james was talking about.
@@EdoKarachannel yes definitely! Though, I'm not sure it would really be worth it. Cast iron is great at distribution, but I wonder if it's really all that necessary since your average moka pot would be much smaller in diameter than you're average cast iron pan. Cast iron heats evenly and would get the edges of the pan as hot as the middle, but the middle might be the only place you really need heat stored. Cast iron would hold the heat longer, but I'm not sure it would be needed for how short a moka pot takes to finish
As someone with a physics degree: I don't think the effect on the starting brew temperature is a result of evaporation of the water inside the boiler. The most significant factor is probably the temperature of the air that gets trapped inside the boiler when you seal it. As soon as you put in hot water, it will heat the layer of air above it, so when you seal it, you're trapping hotter, less dense air. If you put in cold water, the air trapped in the boiler will be colder and more dense. The colder air will undergo a greater rise in temperature, so it will expand more, and push water through the coffee sooner. *UPDATE* I just realised that the safety valve on the boiler can be manually opened by pulling on the little nub protruding from the centre. (It has a bulbous end that you can grip with fingernails.) It's probably a bad idea from a safety point of view to do this when the Moka is hot, but you could in theory use this to bring the boiler pressure back down to atmospheric pressure at any water temperature, and control the starting temperature of the brew.
based on the mass of water and the mass of air and latent heat in the metal, I doubt the air density really matters. The water vapor is what is pushing the liquid through the grinds. It's more than likely a function of the boiling regime and you could assume the space between the water and the paper to be a vacuum at the start in all cases.
@@sO_RoNerY Funny reading your post where you can't even contribute a potential explaination, but are trying to sound smart anyway by criticising people with perfectly reasonable theories. 'Hahahah'.
I think this is my favourite brewing method. The combination of simplicity of design and inexpensive quality home brewed coffee for the people makes this light years ahead of any modern pod design. I agree with all your suggestions about temperature control through the brew. But I would like to add, we keep an unheated cast iron fry pan on the stove next to the coffee pot. There is a foamy phase towards the end of extraction (may vary depending on coffee and grind of course) before it starts sputtering. During this foamy phase is when I pull the pot off the heat and put it on the Cast iron fry pan which acts as a giant heatsink . it prevents any sputtering and get a delicious rich coffee without any of the watered down character of angry sputtered coffee. Besides one needs to drink ones coffee before making the eggs and bacon for breakfast. Love your detail as always and nerdiness. This is why you have 1.2M subscribers.
Thank you for doing all the science, James! I'm happy (and surprised) as to how much on point I am with my own Moka Pot brewing, based on this video. I have an induction stove and I previously used a heavy-bottomed saucepan to heat up my Moka Pot, however after getting a heating plate a few weeks ago I notice that I could extract more coffee by using lower temperatures on the heating plate, and in turn of a slower brewing time, get a much more tasty result. I definitely will be testing out the AeroPress filter soon, as it also seems to make cleaning of the Moka Pot easier and the gasket last longer, in addition to approving taste. Edit: I forgot to mention that in terms of dilution I've found a ratio of 3 parts brew to 2 parts water is a good starting point. I usually do this when making coffee for guests in a 12 cup Moka Pot, then ask them if they think the coffee is too strong and add more water if necessary.
You've basically explained in 1 video what tuck me 20 years of mokapot experience to understand, although I've always preferred aluminium pots because they dissipate the heat faster making it easier to not burn the coffee. I also highly recommend an electric pot they are much much easier to get a consistent brew and efficiently brew without burning
I'm so happy he mentioned the Wired Gourmet's video, which has been the best tutorial for using a moka pot up until now. One thing I think James could test would be blooming the coffee by taking the pot off the heat once the first coffee comes out, then putting it back on after 30 seconds. I wonder how well this specifically affects the evenness extraction.
I brew with the 3 cup moka pot. I remove the pot from the heat when coffee starts to seep through, and that's enough energy to fill up the upper chamber(20grams in 60 out, 1:3). I've timed the extractions, anything over 23secs tends to taste bitter. I use grind size and heat to modify brew times. I guess the voodoo magic didn't work for me, as the brew time was too long and the coffee too bitter.
My family are Italian immigrants to Canada and the Moka part was always a big part of Italian expression when living outside of Italy for us. Thank you for making videos that taught me so much about something that has always been in the background of my life.
I can’t imagine the amount of time, effort, thought, and resources that have to go into making videos this in-depth. I know we can’t have these every week, but I am so grateful that you are willing to go through the work to share this with the community. Thank you for all that you do.
I KNEW it! Moka pot is finicky as hell. It's basically a surprise box, where sometimes it's very good, other times is super burned. This video help me confirming many things I suspected ( the spurting phase, the temp surfing, the grind). Amazing video
Would love to see what a test with a substantial cast iron pan instead of a heating plate would look like. I suspect lots of people are likely to have that in hand, and if it's roughly equivalent to the heating plate, might be a simple option.
Agreed, I was about to post a similar suggestion. The base of a reasonably heavy-based stainless-steel saucepan will essentially be a slab of metal about the same as that heating plate. I guess that's what makes horrible non-induction electric hobs usable at all. So... put your moka pot in a heavy saucepan? Worth a try on old-fashioned electric.
I’ve just made a cup of coffee using the Pot on my Rayburn coal fired range. It has a cast iron plate that changes temperature from one side to the other. With the knowledge from James’s video that the angry steamy bit at the end is a result of too higher temperature, Once the flow had started, I just slid the pot across to the cooler end of the plate and watching to make sure I never got to the angry bit and it made the best coffee so far ( I’ve only had the thing a few weeks) . I’m not suggesting this for everyone but I’m pleased with the result.
I've been making my Moka pot coffee on a heavy set stainless steel pan with a fairly thick base since seeing this video and I'm getting excellent results on the gas stove!
One thing I didn't see you thinking about: I stumbled upon the effect of the relation of water to air in the base; A higher air to water ratio in the base stores more "pressure energy" even at the same pressure. When that pressure is released it will drop slower and take longer to do so. Imagine a car tyre and a bicycle tire at 2 bar, one will take much longer to reach ambient pressure. At some point you will get LESS brew out of a moka pot when adding MORE water into the base, not because you can't reach the pressure to start the brew but because you don't have the volume to sustain it. Not sure yet what to conduct from that and if that effect is significant enough to have an effect on brewing. But maybe that knowledge can make for better coffee. Thanks for your work and passion!
Good point Kalimerakis. I have a 3-cup moka pot that, because of a different base shape, accommodates slightly less (5-10%) water below the valve and more air above than other 3-cup pots and it seems to gurgle and sputter less, making a more consistent brew. It is definitely something for JH to look into!
i also think that you are not able to store more pressure energy since it is a continous process. Imagining having your two tires but you have the normal valve and mount a second pressure relief valve set to some fixed pressure (e.g. the ~1.3 bars at wich the moka pot brews). Now at the beginning both tires are empty and you start pumping air in them. At the beginning both just fill up and the bigger on obvouisly takes longer until you reach the 1.3 bars at which the pressure valves opens. However, once the 1.3 bars is reached when you continue pumping the exact amount of air you press into the tire will come out at the pressure valve again since it lets out all air which exceeds 1.3 bars. So you always effectivley just use the pressure energy you are putting into the system which is over 1.3 bars so your pumping energy which equates to your heating energy in the moka pot case. That said the air water ratio will still have an influnece but i would expect more in terms of how fast you'll reach which temperatures and in smoothing out possible pressure peaks or even influence possible pressure osciliations and other transient effects...
@@peterheinzo515 Look at loodog555's videos of myths about mokapots. He go through scientific papers about moka pots and it's really great. One of the thing that stuck with me is that if you add less water that just under the valve, you'll get more water than if you will it to the valve. I really reccomend the series! th-cam.com/channels/HJ6HdCUV5hgdwQdkfNuz0Q.html
Thank you for your experiments. Your previous videos were extremely beneficial to myself in helping me prepare and brew my mocha pot coffee. Sincerely, I endeavor to persevere.
Aero Press and Moka are my main drivers, this series is amazing! Moka pots are so fussy and I've had great problems with repeating brews. Very cool that you mention the Wired Gourmet technique, his video really helped improve my technique, Looking forward to the next installment.
This video starting with "This thing broke me intellectually, emotionally. It just destroyed me" is not what I would've imagined when I clicked the link. A virtual hug to you, and thanks for this analysis, especially for the "dilute it in water" recommendation, I'll try it next time.
As an avid Moka user I'm loving this series lol. They are very temperamental things, when I first got mine I was researching for weeks to find "the perfect method", all the videos online I was watching had slightly different variations of ways to brew (some completely different), in the end I just kept experimenting until I found the way that worked for me. I think it's about time that someone invented a "Moka 2.0" that has a foolproof method that gives a lovely cup of coffee every time without fail.
So. I've waited many nights for episode 2. After xmas I bought my first moka pot....after playing with just about every other brew method. I've experienced just about everything you took the time to intelligently capture and share! It's a frustrating beast and I am on a mission to make the absolute best coffee I can make at home---and despite it's ongoing challenges, I think it can produce flavours unlike anything else. I have a glass top electric stove. I brew at about a "6" on the dial. The stove works by coming on for a few seconds, then shutting off...then coming back on. At first I thought it would be terrible. But I think it might be perfect....I've NEVER had a sputter at the end. I wait until the coffee fills the carafe 1/2 of the way to the spout channel. I then pull the pot momentarily and I turn the heat to MIN. Then I return the pot to the element (now effectively off but still really hot), and I let it finish. I let the liquid rise to the very very bottom of the spout channel. It's the best I've been able to do so far. And I've counted---exactly 21 "on/off" cycles until coffee flows. And this seems to be the case regardless of how much coffee I use in the filter basket. Thank you for this (and all) episodes!
In 1993, I was gifted a stainless Ilsa version of the Moka pot: it has been used almost EVERY DAY since then. I have no doubts that it will provide me with delicious coffee, to that day when I shall be obliged to surrender my on-loan molecules to the Cosmos❤️ Thank you for this wonderful Doc!
Obviously I wasn't recording any data to back this up but anecdotally, I've also found that using a lower temperature delays the sputtering phase and ultimately gives me a better cup of coffee.
That seems to be my experience as well. I have also found that any sort of compressing the coffee seems to result in issues later like too high heat/pressure and too long brew time and as a result sputtering. I do, however, fill the basket to the brim, unlike James here.
I just got my first moka pot recently after being inspired by your home milk drink episode. I got a stainless steel pot for an induction stovetop. At first I thought I was having trouble building pressure, so I turned up the heat. Nothing but sputter and harshness. Got very little liquid out. I took a step back, and just boiled the base with an empty basket to observe how heat and basket filling correlated and quickly discovered that I had things completely backwards. The basket can fill perfectly well on low heat. So, I switched to a technique where I use medium heat until I get my first liquid and immediately go to lower heat from that point forward. Lo and behold, less sputter, and tasty coffee! One thing to note about induction (or maybe just mine) - they heat in "pulses" so I don't get a continuous consistent flow. It increases and decreases with the heat pulses.
depending on your induction stovetop , it either pulses or it also has other modes where it can supply continuous heat. I had the same problems when I first got mine but realised I had a "boiling" function where it's contanstly heating.
@@terry6080 I think that is the difficulty with electric coils and some induction systems. They can supply continuous heat but it will be at a maximum. The pulsing averages out to "medium" or "low" heat. They might exist, but I have never had an experience with an electric setup that could supply steady heat below maximum.
I love my Bialetti! Over the moon that finally you're focussing on the little beast! I do just off the boil water up to the valve, with 18g dark roast with my 3-cup, drank neat every morning as a heart starter! Thanks, James!
Hi! I do the same so I wonder at what moment you turn of the heat? And how grind your coffee is? Because I use around 16g of coffee but sometimes the taste is not good, I think is something between the grind size or the moment I take the moka out of the stove or maybe I need to add more coffee?
@@ricardozapata3728 Hi Ricardo. My routine is that I boil water, add it to the pot, put coffee in the coffee holder, tap it twice on the table, add a little more and level it with the back of the spoon or with a knife. Then I assemble the pot and put it on a small gas stove (half the size Mr Hoffmann uses) on low heat. I buy ground coffee from a coffee store that grinds especially for moka pots, that means that it is thicker than espresso. I also noticed that if my pot is slighty wet (I always shake well the pot if it hasn't dried from the last washing) the taste is sweeter, less acidic and with stronger aroma. don't use fine grind, it blocks the brewing and tastes awful. I hope you try my method! I perfected it during 30 years of using this 3 cups bialetti.
@@Gotholia I also use low heat but don't know exactly when to turn it off. I just pull the moka out of the stove when the burbling starts but maybe I should turn off the heat before? maybe while brewing?
@@ricardozapata3728 I keep a small cereal bowl with a little cold water, by the stove and when I hear it gurgle, I take the Bialetti off the heat and submerge the base into it to stop the brew. I pour the coffee into a warm, empty cup (I'd warmed the cup with boiled water whilst the Moka is on the stove and emptied it as the moka starts to brew before I pour). About two or three pours will get the full amount as there's still that little bit extra to get out. Pour, upright, pour, upright. Hope that helps. 16g light roast, 18 dark. Grind not too fine.
This is amazing, thanks James! Even though my fav style is filter coffee, as an Italian I was raised among mokas ;) Two urban legends I am aware of two habits from my country and would be curious to hear your take on them: * press the coffee before brewing (sorta of what you would do with an espresso machine).. in theory, this would make for a more "espresso" taste. * keep the lid of upper part open at the beginning of the brewing, and close it once the first coffee starts to come up, while also turning the heat off.. for a more rounded taste. While the first doesn't really hold in my opinion, with all the testing around temperature and pressure in your tests, maybe the second would make a difference? Anyway, keep up the great work!
For your next video, I would be really curious for you to explain the differences of technique between a 3 cup moka pot and a 6 cup moka pot. I own a 2, 3 and 6 cup moka pot and I find it relatively convenient with the small ones to produce nice coffee. With the big one however, it seems incredibly difficult to brew coffee without getting to the wild spitting phase way too early in the process. I am excited to see what you do and how you can possibly avoid this to happen and get enough liquid through before the wilderness starts :D
Any suggestions for the 6 Cup moka? I have a 4 cup right now and am thinking about getting the 6 Cup Coffee Gator Moka. Have you found a method to better heat management with the 6 Cup moka? If you lost your 6 Cup moka would you replace it? Thank you 4 your help.
I love the "nerdy" stuff here. Please do more of these. I tried my moka pot with the filter and it did definitely create a different taste profile. Also it brewed differently as it didn't have the initial foam at the beginning, but came around half way and lasted to the end. I have always knocked the temp down to the lowest setting after the initial brew, but this time I had to keep it up more as it wasn't coming out well with the filter. I will try again with the filter and see if this is repeated.
Thanks! I’ve struggled with the moka pot in the past, to the point that I eventually gave up using it altogether for an aeropress. With these tips I’ve brewed good coffee with my moka pot all weekend. Plus, as someone who teaches Arduino at a college this video has given me the motivation to create my own frankenmoka….
James, another superb video! I have been using a moka pot as my daily for about 8 years now, and found it much easier to get a more consistent (and hands-off) brew using the method you referenced. 👇🏽 This is what works the best for my sealed-top electric range, which has a small element the size of the moka pot base: 1) Measure and add cold water to the base, heat on high to a boil 2) Turn element down to 4/10, remove base from heat, add coffee 3) Screw on the collector, replace about 1/8th of the base (depending on roast and grind) back on the element *No sputtering, no scalding hot collector, no high-acid profile, and a well-textured, nuanced brew* Here's my setup: Moka Pot: Ilsa Slancio 6 cup stainless (this is an older model that has very thick stainless) Coffee: ~30g Water: 400-430g Good luck with your own tests everyone!
As a newbie I had to replay more than I care to admit but there is a tonne of useful advice here - many thanks James! Wondering what else I might glean in the next episode - outstanding work!
The specific heat capacity of aluminum is 0.89 J/gK, and for steel is 0.47 J/gK. So each gram of Al is storing twice as much heat as a gram of steel, at a given temperature. That almost certainly has a lot of impact on your thermal imaging results. It'll also influence how removing the heat source affects the brew: an Al base will have more residual heat to give the water. We could also analyze the moka pot as a heat engine for raising water from the lower chamber to the upper, to get an idea of how many joules we need, at minimum, to complete the brew. At 15cm of height difference between the water and the top of the tube (a total guess; measuring would be better), it should take about 0.24 J to raise 160g of water, once the system is hot enough that things have started moving. Not much, compared to the thermal mass of the base. So I think mostly, once the first drops flow, you just need to keep the base from cooling down (losing heat to the air in the room) to complete the brew. No need to add any significant additional heat.
As the specific heat capacity, it's probably better to use the volumetric heat capacity since the wall thickness are similar rather than the weights of the system.
To rehash what @KJ Dude said, specific heat capacity is per gram. Aluminum has a specific gravity of 2.7, while steel is 7.9. So a given volume of steel will store _more_ heat than the same volume of aluminum. That being said, the steel moka pots I've seen have walls much thinner than aluminum ones (mechanical strength/cost is likely what drives the design). So, in the end, to know which pot has more thermal capacity... you really need to weigh them and multiply for the specific heat capacity.
I'm so glad for this video because all of my moka pot brews were inconsistent and I couldn't understand why. I would do the "exact" same thing and the still weren't consistent so thank you for the mind blowing insight
I think some of the finicky nature for James is his use of light roast specialty coffee. Most of the millions of people using the moka pot are brewing darker roasts. They have also never uttered the words " mouth feel". Traditionally in my Italian/American family, "black coffee" is an after dinner coffee made with a moka pot and diluted. But while diluting it with water is good, diluting it with Sambuca is way better. And by diluting I mean a 50-50 ratio. :-)
James is right. Even when you get your technique nailed down, they can sometimes just have a bad day and channel, or spit, or whatever. Occasionally frustrating.
Thank you! I always wondered what exactly causes this sputtering at the end of the brew. I tried the "the wired gourmet" method a few times, but was always struggling to keep the flow rate low enough to reach 3 Minutes brew time. And it always ends up sputtering. Its great this Mokka Pot topic finally got some attention. There are about a million videos about a dialing in your grind size for espresso but (including this one) only two usefull videos about brewing with a Mokka Pot. My recommended workflow if you use your Mokka Pot for camping: Boil the water in the lower part of the Mokka. In the meanwhile you can grind the beans and fill the basket. When it's about to start boiling put the filter in the pot, screw the upper part onto the pot lightly, put it on the floore where you can fixate the pot with your shoes. After applying the correct amount of torque bring it right back to the stove. The downside is that most people will give you weird looks. But being acquainted to that will make your life easier in general so I count that as a plus.
Gee, I always thought the angry sputtering was the POINT! The announcement... YOUR TRAIN is pulling into the station... your hair flies in the shockwave! Having been introduced to the moka pot 20 years ago, I never went back. Thank you Bialetti! And thank you James for this really informative vid! I too prefer my steal pot, but the aluminum has it's charm. I think it's definitely SWEETER somehow. I won't be bying a heating plate but I will be practicing removal to get max fluid.
There is a rod stand that fits over a gas hob that's designed specifically to hold a Moka pot. It may have enough thermal mass to add enough heat after the gas is turned off. Just a thought.
As a researcher watching this video, brings me so much satisfaction from rigorousness this man is putting in and at the same time starting to doubt whether I put enough thought to my actual scientific experiments!
I really appreciate this research! Not many people (if any) have put this much time and effort into researching this, and released it to the public. We all know more about Moka pots because of your work! 😊
The induction plate discovery makes me think there's an opportunity to build a different bottom section for the moka pot with a heavier metal base. That way you can cut the heat entirely and the base retains enough heat to maintain the rest of the brew
@@confusedwhale I was very surprised by that caption saying that the top section isn't stainless steel. I have that exact pot, and the top section definitely looks, feels and behaves exactly like stainless steel. Plus the product is described by the manufacturer as "stainless steel", and I believe them.
I've been thinking for a long time that I wanted a moka with a thicker bottom and a deeper milling in the center around the basket's tube. Would likely make for a steadier brew temperature with less wasted water left in the bottom.
I'm not sure if someone else mentioned this but you can change the emissivity setting on a thermal camera to account for the reflectivness of a material. It is normally set to around .95 for non reflective materials. Set it lower for more reflective materials. Love your work! You've taught me quite a bit over the past couple of years :).
This was a fantastic video. As someone with a background in infrared imaging systems, my heart swelled when you got to, “so of course we then had to rent an expensive thermal imaging camera…”. Honestly, I’ve been diluting my Moka pot brews for years for that better balance with my own preferences, so it was good to see that you found that helpful as well. I’m really looking forward to experimenting with temperature control and diffusion now, because we bought some Cometeer to try it out and now I’m torn between the obviously superior flavor balance of the Cometeer and the more full-bodied texture that I love from the Moka pot.
This is why this guy is the best here on youtube for coffee no stupid gimmicks or zoom shots / nonsense , pure class content, thanjs james us nerds are grateful
James you scientifically explained exactly what I found after 2 years of experimenting with my Moka pot. The one thing that is absolutely correct, these pots are finicky. Every little change you make changes the brew dramatically. Thanks for showing the data.
As a nerd, physicist, and daily moka pot drinker i love this! After waching this i have been playing around using much lower heat than what i used to do. Doing this i found that on my induction stove (with seemingly stepless adjustment) the lowest heat will make the brew slowly stop, i.e. the temperature in the bottom chamber drops to a level where the pressure is not enough to force water through the coffee. This means that there is an setting (in the upper end of whats presented as 1) where i can make the water flow nice and slow, and keeping the water in the bottom chamber below so low that it never sputters, in the end there is just steam. This completely elinimates the harsh tastes from the high temperatures that you record during extraction. During these experiments i also figure that i expect the cause of sputtering is not steam comming from the bottom chamber, but water that is so hot that it is still above boiling poing after passing through the coffee and filter. In the bottom chamber and in the puck there is an increased pressure that will keep the water from boiling, but in the tube in the top part there is not, so any liquid that will get to the tube with temperatures above boiling point will instantly boil, causing the sputtering.
While it isn't something I've seen in domestic stoves, a temperature controlled hotplate might be your next step in experiments. They're often used in chemistry labs, and if you use one and set it to 100°C, the water shouldn't rise above that temperature. You did test with boiling water, but this would allow for higher temperatures as well. This functionality is something I really want to see in induction stoves, as it would be brilliant for so many types of cooking.
Some very expensive induction stoves do have that (cheaper ones too but I don't really trust them). If I recall correctly they even have connection for a probe to stick inside the pot or whatever (haven't seen a cheap one with that).
I was thinking of a self heating electric moka pot that could regulate the amount of heat it pumps into the water based on the steam temperature measured at the top of the base. A well-tuned PID controller could maintain a very even steam temperature. Maybe this could be the next generation of moka pots (if it doesn't already exist)?
The temperature of the object being heated can rise above the temperature of its heater if it gets heated up faster than it loses heat. So if your insulation is good enough you can definitely rise above the temperature of the heater. Moreover the temperature of the heating plate does not correlate linearly with the temperature of the water inside a moka pot, what matters is the rate of heat transfer so that doesn't give you much control. It does give you some more control over the gas stove but only because it essentially gives you a lot more granular power input setting. What you would need is to somehow control your power input (the heating of the moka pot) based on the temperature inside the moka pot (either the water or "coffee bed" temperature).
@@InTimeTraveller Sorry but that's not how it works. Yes, if it more heat flows in than out it will heat up, but heat always flows along the temperature gradient from hot to cold. So if the heater really is temperature controlled, the pot wouldn't get hotter.
@@FlorianLinscheid the temperature of an object is but an indication, a metric of the thermal energy it has stored inside. The surface temperature of the heating plate is an indication of the energy it has inside, but it's not the only path of energy transfer. For example when he lifted the pot off the plate it kept getting hotter because energy was still getting supplied to the pot via radiative heating and convection and it couldn't lose that energy to the environment fast enough. Rate of heat transfer between the plate and the moka pot and between the moka pot and the surrounding environment is what is going to determine the actual temperature of the moka pot. Especially since we're talking about a timescale of two to three minutes. Temperature gradient does affect rate of heat transfer but it's not the only variable. It's just like voltage in electric circuits: you can temporarily charge a capacitor to a voltage higher than your supply voltage and that's the entire concept behind boost converters. Voltage is similarly an indicator of the energy stored in the system and electrical energy does flow along a voltage gradient as well, but the rate of energy transfer (current) together with the total energy are going to determine the instantaneous voltage at any point in the circuit.
I found a couple comments made in this video very helpful - the bit about pressure increasing temperature, and too high of both being the cause of sputtering. I'm quite new to decent coffee brewing, having just gotten an encore a little over a month ago, and moka pot is my almost singular brewing method. However, I've only been working with fresh beans for the last few days, and due to the Co2 release they behave SO differently from the much older beans I had been using before. Using my old technique on fresher beans was causing my moka pot to clog up and produce very bitter brews. I had a vague idea forming of how the gas release must be affecting the brew but watching these videos clarified it for me - I can visually see the gas release is temporarily retarding the brewing process, so that must cause a build of pressure and thus an increase in temperature, and as Mr. Hoffmann explains that would be a clear cause for the crazy bitterness and sputtering I've been getting. So this morning I tried a lower temperature, and magic! It works, it flows, and way smoother! I had only ever used much older or pre-ground beans so I just didn't understand what my moka pot was doing, but now I feel like I've learned more about the dynamics of this deceptively (not so) simple little brewer. Thanks so very much for the assistance Mr. Hoffmann! Really appreciate it.
I love this breakdown and appreciate all the hard work you put into this! You know it's gonna be great based on how many times he said "and I'll come back to that later". I haven't pulled out my Moka pot in a few years because it was frustratingly inconsistent and takes a longer amount of time and attention, but when it was good, it was great! I do miss the little guy.
Fascinating video. Other things I would like to see tested are - the effect of lightly tamping the coffee to create more resistance, aeropress filter in the base of the coffee basket for more even flow of water, replace filter with E&B competition filter and pre-wetting the coffee bed with cold water to reduce brew temps.
I even fully tamp (like espresso) at this point and get way better extraction that way. Gotta have that coffee filter tho in the base of the basket (!), otherwise you get a ton of channeling...👍
Very cool experiments as usual James! Although the thermal camera part isn't very scientific as aluminum and SS have different thermal emissivity. The shape of the pot also matter as it determines the air flow around the pot thus heat distribution.
The paint used on the strips he measured will have the same emissivity so the temperature readings will be fine. Emissivity is only a surface property, not a bulk material property. The only question is what emissivity he used (should be .91-.95 for most paints).
As someone involved in research I can really appreciate this, it takes a lot of time and effort to set this up. Us viewers are all appreciative of your in depth dive into this now modern classic coffee making method. I hope you and your team actually manage to publish some of this @James. The stainless vs aluminium was what I was waiting for in particular. There is an art to getting a good moka coffee, always seems as if a bit of luck is required.
Putting the water added at the end in the upper pot instead(prior to brew) keeps the temp down on the grind and smooths out the spike in temp at the end, other than that this was friggin awesome!!
I’d be curious to know more about how the amount of coffee you add to the basket influences the brew (taste especially). As a Southern Italian, I was taught to create a “little mountain” of coffee in the mountain (without pressing coffee down), but I know in other parts of Italy they’d put way less coffee in (like you showed). Would you test this further?
I have a Brikka version of the Moka pot so it added additional pressure to the system which make it tricky to “control “ the pressure. I use 17g of medium roasted coffee with hand grinder at a very fine setting. Hopefully James will get to the Brikka soon.....
I think it could be interesting to look at the design of the lower chamber. Does more or less airspace at the top mean higher and lower brew temp because it's more area that needs to get pressurized? Does lower chamber design dictate how the water raises once heated? Space vs mass of water vs surface area (tall and narrow vs wide and low) Also, a larger thermal mass could be interesting to experiment with, like a larger steel plate that would heat slower and lose heat slower.
An add on to this would be noting how the placement of the pressure valve (if indeed you shouldn’t fill above it) restricts capacity and impacts the ratios you brew with
This is a really good thought. I could see using a side chamber with a bladder, or sprung piston to have a reservoir of pressure to remove it from the heat but continue the brewing.
I'm very excited because I've actually used this same exact induction plate method for months now (as I got the inspiration from wathing Wired Gourmet and the slow brew he presents) and it really works! Thank you James for one of your best videos!
Hey, James. This video is truly amazing for understanding what's going on in moka. I have an idea for better heat accumulation, maybe you should place moka in a pan with sand, like a cezve in Turkish coffe making method. It has really large thermal mass. So you heat the sand, cut the heat from stove and place moka there.
Thermal engineer here! To answer why the Aluminum moka pot is colder than the stainless steel one: Specific heat is a thermal property measuring how much heat can be absorbed into a material. Think of it as a sponge. Aluminum has a higher specific heat than Stainless steel (921 J/kgK vs 502J/KgK). This means that for the same amount of energy put into the aluminum vs stainlss steel, the aluminum will "soak up" the energy better, and have a lower temperature rise than the stainless steel.
The biggest revelation for me in this video was the overheating and sputtering. Now I get an evenly extracted clean brew every single time through preventing the water from from steaming inside... I have three (3) Moka pots and I have struggled to create some systematic around brewing to get a decent cup frequently. Now the biggest problem is solved. Off to coffee heaven!! Ps. This is easily the best video on TH-cam, and I will be forever greatful for your input for the Coffee community.
It is very satisfying to hear how finicky these are. I have had so many extremely delicious coffees from a Moka pot and even more horrible bitter ones. I have a love hate relationship with the pot because I'm convinced it is capable of making a delicious brew but have had enough bad experiences that I keep trying different methods for brewing. This was a very enlightening video on the subject. Thank you so much!
This is one of my favorites of all your videos. Really interesting, and I always appreciate your honesty and humility when the data teaches you something.
Regarding the termal imaging portion: The first thought that comes to my mind is that the steel pot likely has much thinner walls than the aluminium one, so even though aluminium is a better conductor, the steel has far less thermal mass to heat, which is why it heats quicker. This would also explain why the cooler brewed coffee shows through the thin walls much more quickly.
2 ปีที่แล้ว
That’s a good input. To add to it, I think the geometry plays a role here as well, with the wider base of the aluminium pot shielding the hot air better than in the stainless steel pot. To support this, I think it is noticeable that the heating in the SS pot starts on a localised, isolated spot, rather than continually from the bottom up.
Thermal imaging also varies based on thermal refraction factor. He's seeing different depths of heat here because the material thermal refraction properties are different.
Hoffmann mentioning my idol "The Wired Gourmet" made my day! I gotta admit, his technique for Moka Pot made my coffee way better than Hoffmann's and now he's kinda "recognizing" it with scientific data. What a great tool TH-cam is! Coffee brewed to perfection !
I was surprised you didn't look at the amount of coffee used as a variable. I'd imagine that less coffee would both reduce extraction as there is less to extract, but also pressure, as there is less coffee to press against. What would be the recommended coffee to water ratio?
I tried this method with a ribbed cast iron skillet & didn’t get any sputtering at all! I tried it with the recommended method: • Stainless steel moka pot • Good quality fresh ground coffee • Boiling water Heated the moka pot on a HOB with a cast iron ribbed skillet as the heat shield. Came out delicious! Not over extracted. Nice sweetness. This setup kept the moka pot on a slow pace and never went further (no sputter at all). Perfect!
I just wanted a cup of coffe and now I'm involved in a brewery cult:- °
FOR THE GREATER GOOD!
😂😆😂 we're all diving in
Oremus, frater
@@uffa00001 🤣😂
😂😂😂
Nerdy content about coffee is why I'm here. Please don't stop making it nerdier with the nerdiest in mind ♥️
Speaking of the intro, is it just me or did anyone else (mis-)hear a naughty undertone?
100%. This is the reason I watch James's content. Other channels might do tests and experiment. No one else is going to have not one, but two, frankenmoka pots built. And then proceed to do a couple weeks worth of testing and data collection. I come to James Hoffmann for coffee science
Master, Master the Mokapot is alive.. Don't let the villagers see it!
Could we exchange "nurdy" (does rime with "durdy") to "inventively analytic" ?
Hear hear…
The way that James said “telephone” instead of “phone” really made me believe he’d hooked the Frankenmoka up to his landline.
Hello? Yes this is moka
Glad I wasn't the only one confused by that choice of words
brought a dialup modem to mind for sure
My first thought also was: "there's nobody going to call you from in there, why would you do that?"
@@awogbob "scusi? a-YEs, this is a-MOka"
This could literally satisfy the requirements of a BSc thesis. Very well done
Close to an MSc thesis if you were to include the design and build of the two frankenmokas.
As a scientist in basic research, I’m flabbergasted by your approach! From designing the experiment, building the equipment, methodical data collection and documentation to the critical analysis - just awesome!
As an engineer, this is exactly the content I love to watch. Data, analysis, and experimentation. I love this so much.
This could also be a full on dissertation too. James probably should go for James Ph.D at this point.
Maybe test for asperger/autism you maybe on the spectrum.
As a fellow engineer, I completely agree. I love his methodical, analytical approach.
@@muklukPL you are projecting
@@muklukPL you're on the spectrum as well
Arguably the best video you’ve ever made. As an Italian guy I feel flattered that you decided to dedicate your attention to this brewer. It’s really frustrating the process of making a good brew out of this thing. I’m looking forward to watch your next video in this series and I’m sure it’ll give me a huge help! THANK YOU
Do most Italians who drink moka pot coffee share your opinion on moka pot?
I'm Italian as well and the whole family and Nonna included uses this Moka. I've never imagined it would be so tricky. I just use lavazza oro up until the top of the filter (a little bit before that actually), room temperature water at the limit. No induction, gas. Low heat.
Always works fine...
I believe using the plate is wrong. They designed a Mock specially for induction also if you check in their website.
:)
@@KAESowicz afaik most italians believe the wives tale about letting coffee build up in it and to never clean it with more than a rinse under the tap.
@@jonmahashintina Well then you don't know much.
Nobody that I know does that.
We don't clean with soap. But we vociferously clean it to make it like new. They usually outlast you.
@@incognito8023 What is your sample size for moka pots that out lasted their owners?
Honestly, this amount of science behind the Moka Pot in terms of the coffee community producing the results is long overdue, and very much appreciated coming from you. Thank you so much for your dedication to the data!
@@pamusso1466 This isn't about the boiling point of water, it's about the average temperature of the water going through the coffee.
@@pamusso1466 You seem to have misunderstood how a Moka pot works - the water is pushed through the tube by steam pressure, it doesn't go through the coffee while it's steam.
James: "Warning: The video gets very very nerdy."
Me: Yay! :D
But you're food geek not food nerd, the betrayal ! ...
First time I've hit an instant like for a video)
As an Italian I'm very grateful to be properly schooled on moka. Thx so much for your service to our culture.
P.s. I still can't have coffee at my parents because it sucks badly, but my home brew is now top notch 👌
I'm sorry. That really sucks. As they get older their taste buds are less sensitive and they will just feel the bitterness of the coffee rather than actually tasting the sweet, fruity, and floral notes.
I had a friend who's dad was in his 80s and he used a stove top percolator and just let that thing sit for so long. Bitter mud was produced. That stuff would blow out your intestines!
May you have a great day and many Happy brews!
😢😅
@kg8568 😂 my uncle was in the military and his wife clean their coffee machine and he had a complete freaking meltdown because she ruined the flavor. He calls the build-up of oils and stuff seasoning instead of realizing once you leave it sit for a couple weeks when you're on vacation there just Rancid coffee oils. He buys cheap coffee in bulk and the darkest roast so I got an inkling what you dealt with but I've never had to deal with super over percolated coffee except one time when I personally didn't know what I was doing and tried to make it for a holiday party haha... some of the older folks were fine with it but the rest of us were just like nope or made it mostly sugar (like 7 tsp sugar in my mug, half full of half and half 😳
This was great. It explains why I started grinding finer when I was living at altitude (12,000 ft / 3650 m), where water boiled at 190F (87c) - meaning impossible to make a decent French press - but a mocha pot with the finer grind worked -- forced pressure up, and therefore temperature. It also explains why that part of the world is not a coffee culture - you couldn't get the water hot enough to do a decent extraction -- unless you had pressure.
this sounds like an idea for a video! brewing at different altitudes 😁
Its crazy that you lived that high up for any extended period. Were you in South America or Asia?
Oh, that's great observation! Where did you live, if you don't mind answering?
James be like: "I'm currently inside of a pressure chamber at 12k ft above sea level. In this video I will show you how to make coffe in a french press, aeropress, mocha pot and yes a bripe. I am also not going to keep this pressure chamber as it will go to one of my patreons."
Follow-up video will be him in scuba gear, brewing coffee under water.
@@kivzzzz that is the altitude of la paz, the capital of Bolivia ( just a guess from another high altitude coffee enthusiast )
The aluminum vs steel test was very interesting and also makes sense to me. Basically answers the question of why we have clad cookware. Aluminum heats very evenly but retains heat poorly, while steel retains heat well but heats uneven. When you sandwich aluminum between steel (ie, cladding it) you get the best of both: even heating and good retention. Now someone just needs to make a clad moka pot!
Aluminium retains heat well, but needs to be a bit thicker to do so successfully. The reason why aluminium is sandwiched in clad cookware is because it is highly reactive to food AND cleaning detergents. I have a thick Demeyere Proline pan that retains heat as well as my cast iron pans.
@@lgolem09l I think that aluminum conducts heat well, so it distributes well across the metal, but it retains heat poorly, which is why if you move aluminum away from a heat source it cools down rapidly. Steel conducts heat poorly, but retains it well. This observation tells me that conduction and retention are related; if it conducts well, it retains poorly and vice versa.
@@Taku071090 aluminium has almost twice as much heat capacity than carbon steel, but that is per kg. Carbon steel is a lot more dense though, so at the same thickness, it wins because of that. A thick aluminium pan can have both advantages, that's what I use. Also, copper does well at both, even at low thickness.
We can't do an ironclad comparison (pun intended) of different alloys by just discussing singular elements. Yes pure aluminum is a better heat conductor than pure iron (it also dissipates heat faster), but Stainless Steel (Austenitics or "300 series") is comprised of 0.015% to 0.10% carbon, 16% to 21% chromium, 6% to 26% nickel, 0% to 7% molybdenum, with the remaining being iron of course. I've had some difficulty tracking down the grade/series of the aluminum moka pots used by Bialetti, but I did find one study that used an XRF Spectrometer on their sample and identified the bottom boiler to be comprised of 67.07% aluminum, the basket/filter to be 94.92% aluminum and upper chamber to be 78.51% aluminum; feel free to guess the grade/series being used... I'm SURE heat retention was taken into consideration when developing these products, but I believe the main reason Bialetti aluminum pots have thick casting is simply because aluminum is rather malleable. Have you ever tried crushing an empty steel can of green beans by hand? Its thickness is comparable to an aluminum can of soda, but the aluminum can is miles easier to crush. Who wants to use a pot that warps too easily? If I was going to sell aluminum cookware, I'd make the metal thick too. Keeping all that in mind, the earlier heat read of the stainless steel model is likely due to the upper chamber simply being so thin, after all it's steel, it doesn't need to be super thick to be sturdy.
There's something beautiful and very Hoffman about taking the Mokka pot, the epitome of simplicity and turning it into something that looks like it belongs on the ISS
ISSPRESSO
@@errornogo 👏👏👏
@@errornogo Perfect!!!
That's my contender for The Word of the Year 2022 contest right there.
Watched this video yesterday, dug my moka pot out of storage, and proceeded to make the best moka pot coffee of my life this morning... Thank you, James!
It's amazing the amount of effort James put into these "understanding" videos. I'm an owner of a moka pot, it's my main device to make coffee and this is super useful, can't wait to the next video.
One common recommendation I got when I had a moka pot was to put a bit of cold water in the top chamber to kind of regulate the temperature during brewing, so that once the coffee comes out, it doesn't hit overly hot metal. I had some encouraging, but mixed results with it, and I feel like it would be interesting to test with your, much more controlled setup.
Yes, this! The moka by-pass. I got that from the previous moka pot champion from... Italy (where else?) Alberto Polojac.
yeah, I was gonna mention this one also. :)
the reason for it, according to my friend at the time, was to control the temperature also as you said, but after watching this video it made me wonder if it also helps by diluting it a bit.
it is a lot less water than suggested in the video for diluting it, but it should still increase the final amount for at least a "sip" I guess hahaha
Great idea!
Also, what about a few ice cubes?
Edit: It works, I suppose! I set aside 40-50g of ice in a cup and dump them in my ("3 cup" bialetti) moka as soon as the brewing starts. I can't say for certain if it tastes better as I haven't felt like brewing two pots in a row but I do know that it's cooled down to a good drinking temp.
Interesting one. Thank youu
The David Attenborough of coffee taking us on a journey into the fascinating life of coffee interacting with the Mokapot. Bravo!
Ah, a mashup is obviously needed: “There are some four million different kinds of animals and plants in the world. Four million different solutions to the problems of staying alive. And another million solutions to the problems of brewing a delicious cup of coffee.”
I love that you said "ignorance is bliss" and I couldn't agree more! I love this nerdy videos despite me understanding almost nothing of it. I use a moka pot and for me is extremelly easy because I don't know all the little things about the coffee I'm drinking.
Great video as always!
Absolutely agree. I don't understand a lot of what he is talking about but I could listen to him all day.
as italian, growing up with nerdy million dollar questions on all the variables to make moka coffee, I was surprized when you said about the aeropress "this is exciting because you can control so many variables and have competitions on how to make coffee".
Now I see that all my waiting to see how crazy you can go with the moka was well worth it!!!!
Thanks for the video!!
(in my opinion this video alone should grant you italian citizenship if you do not have it already)
I love it! 😆 Here in Italy, the "sputtering" sound does mean Coffee time! And that's probably why Moka coffee sucks most of the time! Lots of learnings here! thanks! ✅
Somehow this has validated like 90% of my technique that I’ve developed through trial and error over the years and I am thoroughly pleased about that. Very excited to use all this next-level info that I otherwise wouldn’t have access to on my own to play around with things and tweak my technique to an even more ideal and repeatable brew. Thank you James!!
Would you mine develop it? Is it classified information?
Agree, same here.
My Moka pot was extremely inconsistent until I lubricated the joint and the screw with vegetable oil (I used peanut; then of course the first(s) brews need be disposed of). This very simple yet effective trick I randomly found on the Internet after a lot of frustration and bad coffee made my pot not only work consistently, but also (and most surprisingly) almost fully stop the angry spluttering. Thanks to the lubrication there's virtually no pressure loss through the joints and coffee flows evenly throughout the brew until the end, where it gently and not angrily foams a bit and becomes lighter in color. It is at that point that I remove it from the stove and cool down the pressure chamber as indicated by James. I have the steel (induction) Bialetti, where I use medium-ground coffee, pour boiling water in the cold pressure chamber, and brew on a gas stove at quite a low flame (not the lowest though). Coffee is really good and balanced in this way.
hope he sees this! so interesting im gonna pick one up tomorrow morning 🤧
I might not be understanding this correctly, but by "joint and the screw" do you mean the screw-thread that joins the upper and lower chambers together? If so, that thread is not intended to provide any seal at all - the seal is provided by the rubber gasket. Applying some lubricant to the gasket may allow a degraded gasket to seal better (temporarily) but replacing the gasket would be the best thing.
@@Rowlph77 Thanks for your reply! With joint I meant the sealing gasket indeed. With screw I meant the screw thread indeed. I know that this particular screw is not air tight, but lubrication really does help the whole thing work more consistently (I'm an engineer, I know a thing or two about screws ;-) ). Also, the gasket was new and the machine was inconsistent from day one, so it was not an issue of a degraded gasket, which indeed as you mention would need be replaced. In any case that's what I did and it works for me, so I was happy to share the tip :-).
@@ignaciopardo8963 Thanks - I'm going to try this tomorrow then! Although my gasket is not new, it's still in good condition. I just have ordinary vegetable oil to hand, will be interested to see if it stops/reduces the sputtering at the end.
I may give this a try. I have found I have had to torque the nuts off (the technical term, I believe) the thread to ensure a decent-sized extraction. So actually could a better gasket from different material save all of this hassle or can it not be saved without a tighter toleranced thread?
N.B I also have one of the stainless versions
We just tried the suggestion of turning down the heat once the coffee starts flowing, and our volume output increased. Cool! We made our usual milk drinks. Then, because we had some extra coffee, we each took a taste of it straight. Wow! The flavor is wonderful, noticeably less bitter, and my husband was so impressed, he even said he could probably drink this coffee without milk. Obviously, we didn't want to waste our milk drinks, so we then drank those, but next time, I might try out a cortado-style drink instead of my usual "latte." Cheers!
I turn off the heat when i see coffee comes out.
So for your milk drink, add whipped cream on top. Then take that extra coffee and pour it over the whipped cream. Adds a lot of depth to the drink and the sweetness tamps the bitterness of the straight coffee so you really get the other notes.
Did you stop the brew with cold water at the end? I believe it helps.
@@kg-Whatthehelliseventhat Yes, we always use a bowl of cold water to dip the bottom of the Moka Pot into it (rather than go across the kitchen to the sink with a hot metal thing while our cats are rubbing all around our legs for attention and/or food).
@@dstinnettmusic That sounds heavenly. I'll mention it to my husband for next time!
What an incredible video. I changed a few things today: starting temperature (hot rather than cold), heating on a moderate heat and whipping the pot off when it sputters/running it under the cold tap. Wow -- *what* a smoother brew! And credit, as always, for chapter headings in the video. Another subscriber right here!
This is James at his very best, the most detailed video ever on the moka pot brewing technique, enjoyed every minute of the review!
It really seems like THIS is the content you love making 😁 So much attention to detail, so much time invested, you can even hear the excitement and interest in your voice as you explain the real world effects of the data
All this time, money, and resources dedicated to just helping people understand a coffee brewer, and even then you hold a raffle for a charity doing wonderful work... You're a coffee saint, James
This man is insane, and I love it! It’s literally physically exciting to watch a video of a guy doing all the stuff you wouldn’t/couldn’t ever do yourself, although you probably fantasize about all of this. Truly amazing.
James, what you are doing for the Mokapot is amazing. Showing everyone what has to be done in any development ... staying curious.
Nice video James! I've been a thermal engineer for almost 40 years and you handled this testing well - very well. I'd give you an A+ grade!
My only comment is that the radiative heating when you lift the Moka pot off the diffusion plate isn't has large as you think - because the emissivity of the Moka pot is very low. The diffusion plate may be low or high depending on material's surface finish (anodized aluminum is high, but a polished steel would be low). Likely what you are seeing is a reduced heat loss through the sides of the pot because of the hot air flow around the pot in the air, and also you are using the stored thermal energy in the Moka pot to continue the brewing process.
Nonetheless, this was very well done - congrats!
Thermal engineer sounds like a job in the engine room of the enterprise
WOW!!!
This is actually groundbreaking research, I don't think at any other point in time has the Moca pot been studied as in depth as this!!!!
Love it!!!!
One interesting upgrade to consider is Bialetti Brikka - it has additional valve to build up pressure and prevent brewing with colder water I think. It would be great to hear your thoughts about such upgrade.
Episode 4 will cover this and other pot variations
@@jameshoffmann So we will be blessed with even more episodes! Thank you for your great work.
@@jameshoffmann can't wait!
@@jameshoffmann Have you heard of the Essopot? Also included in ep.4?
@@jameshoffmann is the Ikea version included :D?
When you talked about diffusion plates on a gas stove, it reminded me of a solution I had to making my moka coffee a few months ago. The gas stove I was using had grates too large to fit my tiny moka pot on it, so I had to place a frying pan on the heat, and then place my moka pot on top there. Maybe this could help you in the diffusion plates situation. A frying pot should be able to hold heat, though I don't know how it would compare to a diffusion plate. I can say that usually on a gas stove I find it difficult to make a good pot because of the high heat that even the low setting provides, and a frying pan helped with that.
I've had a mokapot for years, but i have an induction stove, so I've never tried it.
Why didn't I think of using a frying pan???
I'll do it the first time tomorrow!
I'm so excited!
@@Bulleht It works a charm. I've been using an original aluminium pot on induction for 7 years now using a thick bottom pan as a sacrificial heatdisperser. Now I've seen this vid I'm really going to experiment a bit :)
I Imagine something like a cast iron would do a similar thing too, with even more thermal mass to sort of "smooth out" the heat like james was talking about.
@@EdoKarachannel this, cast iron pans are used because they act as an energy store that evenly releases heat into the food.
@@EdoKarachannel yes definitely! Though, I'm not sure it would really be worth it. Cast iron is great at distribution, but I wonder if it's really all that necessary since your average moka pot would be much smaller in diameter than you're average cast iron pan. Cast iron heats evenly and would get the edges of the pan as hot as the middle, but the middle might be the only place you really need heat stored. Cast iron would hold the heat longer, but I'm not sure it would be needed for how short a moka pot takes to finish
The moka pot and aero press are my two favorite ways of making coffee. The induction compatible Venus Moka pot is great.
As someone with a physics degree: I don't think the effect on the starting brew temperature is a result of evaporation of the water inside the boiler. The most significant factor is probably the temperature of the air that gets trapped inside the boiler when you seal it. As soon as you put in hot water, it will heat the layer of air above it, so when you seal it, you're trapping hotter, less dense air. If you put in cold water, the air trapped in the boiler will be colder and more dense. The colder air will undergo a greater rise in temperature, so it will expand more, and push water through the coffee sooner.
*UPDATE* I just realised that the safety valve on the boiler can be manually opened by pulling on the little nub protruding from the centre. (It has a bulbous end that you can grip with fingernails.) It's probably a bad idea from a safety point of view to do this when the Moka is hot, but you could in theory use this to bring the boiler pressure back down to atmospheric pressure at any water temperature, and control the starting temperature of the brew.
based on the mass of water and the mass of air and latent heat in the metal, I doubt the air density really matters. The water vapor is what is pushing the liquid through the grinds. It's more than likely a function of the boiling regime and you could assume the space between the water and the paper to be a vacuum at the start in all cases.
Funny reading both your posts trying to sound smart. Hahahah.
@@sO_RoNerY hahaha ikr
Basically it relates to taste either starting at cold or hot brew as the Chef always sensitive to the tastes...
@@sO_RoNerY Funny reading your post where you can't even contribute a potential explaination, but are trying to sound smart anyway by criticising people with perfectly reasonable theories. 'Hahahah'.
I think this is my favourite brewing method. The combination of simplicity of design and inexpensive quality home brewed coffee for the people makes this light years ahead of any modern pod design.
I agree with all your suggestions about temperature control through the brew. But I would like to add, we keep an unheated cast iron fry pan on the stove next to the coffee pot. There is a foamy phase towards the end of extraction (may vary depending on coffee and grind of course) before it starts sputtering. During this foamy phase is when I pull the pot off the heat and put it on the Cast iron fry pan which acts as a giant heatsink . it prevents any sputtering and get a delicious rich coffee without any of the watered down character of angry sputtered coffee.
Besides one needs to drink ones coffee before making the eggs and bacon for breakfast.
Love your detail as always and nerdiness. This is why you have 1.2M subscribers.
Thank you for doing all the science, James!
I'm happy (and surprised) as to how much on point I am with my own Moka Pot brewing, based on this video. I have an induction stove and I previously used a heavy-bottomed saucepan to heat up my Moka Pot, however after getting a heating plate a few weeks ago I notice that I could extract more coffee by using lower temperatures on the heating plate, and in turn of a slower brewing time, get a much more tasty result. I definitely will be testing out the AeroPress filter soon, as it also seems to make cleaning of the Moka Pot easier and the gasket last longer, in addition to approving taste.
Edit: I forgot to mention that in terms of dilution I've found a ratio of 3 parts brew to 2 parts water is a good starting point. I usually do this when making coffee for guests in a 12 cup Moka Pot, then ask them if they think the coffee is too strong and add more water if necessary.
You've basically explained in 1 video what tuck me 20 years of mokapot experience to understand, although I've always preferred aluminium pots because they dissipate the heat faster making it easier to not burn the coffee. I also highly recommend an electric pot they are much much easier to get a consistent brew and efficiently brew without burning
I'm so happy he mentioned the Wired Gourmet's video, which has been the best tutorial for using a moka pot up until now.
One thing I think James could test would be blooming the coffee by taking the pot off the heat once the first coffee comes out, then putting it back on after 30 seconds. I wonder how well this specifically affects the evenness extraction.
I brew with the 3 cup moka pot. I remove the pot from the heat when coffee starts to seep through, and that's enough energy to fill up the upper chamber(20grams in 60 out, 1:3). I've timed the extractions, anything over 23secs tends to taste bitter. I use grind size and heat to modify brew times. I guess the voodoo magic didn't work for me, as the brew time was too long and the coffee too bitter.
@@Pseudosurfer I noticed that with the 3-cup Bialetti as well. Once it starts, it has enough energy to finish by itself.
My family are Italian immigrants to Canada and the Moka part was always a big part of Italian expression when living outside of Italy for us. Thank you for making videos that taught me so much about something that has always been in the background of my life.
I can’t imagine the amount of time, effort, thought, and resources that have to go into making videos this in-depth. I know we can’t have these every week, but I am so grateful that you are willing to go through the work to share this with the community. Thank you for all that you do.
Ditto!
I KNEW it! Moka pot is finicky as hell. It's basically a surprise box, where sometimes it's very good, other times is super burned. This video help me confirming many things I suspected ( the spurting phase, the temp surfing, the grind). Amazing video
Keeping it clean and doing vinegar or just boiling water on the stove should stop the burnt taste.
Would love to see what a test with a substantial cast iron pan instead of a heating plate would look like. I suspect lots of people are likely to have that in hand, and if it's roughly equivalent to the heating plate, might be a simple option.
Agreed, I was about to post a similar suggestion. The base of a reasonably heavy-based stainless-steel saucepan will essentially be a slab of metal about the same as that heating plate. I guess that's what makes horrible non-induction electric hobs usable at all. So... put your moka pot in a heavy saucepan? Worth a try on old-fashioned electric.
It would also be pretty convenient if you make eggs for breakfast, preheat you cast iron by making your coffee
I’ve just made a cup of coffee using the Pot on my Rayburn coal fired range. It has a cast iron plate that changes temperature from one side to the other. With the knowledge from James’s video that the angry steamy bit at the end is a result of too higher temperature, Once the flow had started, I just slid the pot across to the cooler end of the plate and watching to make sure I never got to the angry bit and it made the best coffee so far ( I’ve only had the thing a few weeks) . I’m not suggesting this for everyone but I’m pleased with the result.
Yes, exactly, commented before seeing this!
I've been making my Moka pot coffee on a heavy set stainless steel pan with a fairly thick base since seeing this video and I'm getting excellent results on the gas stove!
One thing I didn't see you thinking about:
I stumbled upon the effect of the relation of water to air in the base;
A higher air to water ratio in the base stores more "pressure energy" even at the same pressure.
When that pressure is released it will drop slower and take longer to do so.
Imagine a car tyre and a bicycle tire at 2 bar, one will take much longer to reach ambient pressure.
At some point you will get LESS brew out of a moka pot when adding MORE water into the base,
not because you can't reach the pressure to start the brew but because you don't have the volume to sustain it.
Not sure yet what to conduct from that and if that effect is significant enough to have an effect on brewing.
But maybe that knowledge can make for better coffee.
Thanks for your work and passion!
i dont think thats correct.
Good point Kalimerakis. I have a 3-cup moka pot that, because of a different base shape, accommodates slightly less (5-10%) water below the valve and more air above than other 3-cup pots and it seems to gurgle and sputter less, making a more consistent brew. It is definitely something for JH to look into!
i also think that you are not able to store more pressure energy since it is a continous process. Imagining having your two tires but you have the normal valve and mount a second pressure relief valve set to some fixed pressure (e.g. the ~1.3 bars at wich the moka pot brews). Now at the beginning both tires are empty and you start pumping air in them. At the beginning both just fill up and the bigger on obvouisly takes longer until you reach the 1.3 bars at which the pressure valves opens. However, once the 1.3 bars is reached when you continue pumping the exact amount of air you press into the tire will come out at the pressure valve again since it lets out all air which exceeds 1.3 bars. So you always effectivley just use the pressure energy you are putting into the system which is over 1.3 bars so your pumping energy which equates to your heating energy in the moka pot case. That said the air water ratio will still have an influnece but i would expect more in terms of how fast you'll reach which temperatures and in smoothing out possible pressure peaks or even influence possible pressure osciliations and other transient effects...
@@peterheinzo515 Look at loodog555's videos of myths about mokapots. He go through scientific papers about moka pots and it's really great. One of the thing that stuck with me is that if you add less water that just under the valve, you'll get more water than if you will it to the valve. I really reccomend the series! th-cam.com/channels/HJ6HdCUV5hgdwQdkfNuz0Q.html
James is the David Attenborough of Coffee.
Absolutely!!!
totally agree about that!
Thank you for your experiments. Your previous videos were extremely beneficial to myself in helping me prepare and brew my mocha pot coffee. Sincerely, I endeavor to persevere.
Aero Press and Moka are my main drivers, this series is amazing! Moka pots are so fussy and I've had great problems with repeating brews. Very cool that you mention the Wired Gourmet technique, his video really helped improve my technique, Looking forward to the next installment.
This video starting with "This thing broke me intellectually, emotionally. It just destroyed me" is not what I would've imagined when I clicked the link. A virtual hug to you, and thanks for this analysis, especially for the "dilute it in water" recommendation, I'll try it next time.
As an avid Moka user I'm loving this series lol. They are very temperamental things, when I first got mine I was researching for weeks to find "the perfect method", all the videos online I was watching had slightly different variations of ways to brew (some completely different), in the end I just kept experimenting until I found the way that worked for me.
I think it's about time that someone invented a "Moka 2.0" that has a foolproof method that gives a lovely cup of coffee every time without fail.
the "9Barista"James showed seems to be a Moka 2.0
@@tristanwegner They're cool, but like the Moka they're also a bit finicky, and they're pricey, and there's only one size as far as I'm aware.
So. I've waited many nights for episode 2. After xmas I bought my first moka pot....after playing with just about every other brew method. I've experienced just about everything you took the time to intelligently capture and share! It's a frustrating beast and I am on a mission to make the absolute best coffee I can make at home---and despite it's ongoing challenges, I think it can produce flavours unlike anything else. I have a glass top electric stove. I brew at about a "6" on the dial. The stove works by coming on for a few seconds, then shutting off...then coming back on. At first I thought it would be terrible. But I think it might be perfect....I've NEVER had a sputter at the end. I wait until the coffee fills the carafe 1/2 of the way to the spout channel. I then pull the pot momentarily and I turn the heat to MIN. Then I return the pot to the element (now effectively off but still really hot), and I let it finish. I let the liquid rise to the very very bottom of the spout channel. It's the best I've been able to do so far. And I've counted---exactly 21 "on/off" cycles until coffee flows. And this seems to be the case regardless of how much coffee I use in the filter basket. Thank you for this (and all) episodes!
Great job. I am happy 4 you. Coffee is a great hobby/ obsession, may you have many Happy brews.
This is very helpful for me, a glass-top burner owner. I'm just about to start with a Moka pot and your comment will save me much experimentation.
In 1993, I was gifted a stainless Ilsa version of the Moka pot: it has been used almost EVERY DAY since then. I have no doubts that it will provide me with delicious coffee, to that day when I shall be obliged to surrender my on-loan molecules to the Cosmos❤️ Thank you for this wonderful Doc!
Obviously I wasn't recording any data to back this up but anecdotally, I've also found that using a lower temperature delays the sputtering phase and ultimately gives me a better cup of coffee.
That seems to be my experience as well. I have also found that any sort of compressing the coffee seems to result in issues later like too high heat/pressure and too long brew time and as a result sputtering. I do, however, fill the basket to the brim, unlike James here.
so what temperature do you use?
I found the same.
We're using tongue data. No numbers, but if it tastes better then we keep doing it :)
I just got my first moka pot recently after being inspired by your home milk drink episode. I got a stainless steel pot for an induction stovetop. At first I thought I was having trouble building pressure, so I turned up the heat. Nothing but sputter and harshness. Got very little liquid out. I took a step back, and just boiled the base with an empty basket to observe how heat and basket filling correlated and quickly discovered that I had things completely backwards. The basket can fill perfectly well on low heat. So, I switched to a technique where I use medium heat until I get my first liquid and immediately go to lower heat from that point forward. Lo and behold, less sputter, and tasty coffee! One thing to note about induction (or maybe just mine) - they heat in "pulses" so I don't get a continuous consistent flow. It increases and decreases with the heat pulses.
depending on your induction stovetop , it either pulses or it also has other modes where it can supply continuous heat. I had the same problems when I first got mine but realised I had a "boiling" function where it's contanstly heating.
@@terry6080 I think that is the difficulty with electric coils and some induction systems. They can supply continuous heat but it will be at a maximum. The pulsing averages out to "medium" or "low" heat. They might exist, but I have never had an experience with an electric setup that could supply steady heat below maximum.
I love my Bialetti! Over the moon that finally you're focussing on the little beast! I do just off the boil water up to the valve, with 18g dark roast with my 3-cup, drank neat every morning as a heart starter! Thanks, James!
Hi! I do the same so I wonder at what moment you turn of the heat? And how grind your coffee is? Because I use around 16g of coffee but sometimes the taste is not good, I think is something between the grind size or the moment I take the moka out of the stove or maybe I need to add more coffee?
@@ricardozapata3728 Hi Ricardo. My routine is that I boil water, add it to the pot, put coffee in the coffee holder, tap it twice on the table, add a little more and level it with the back of the spoon or with a knife. Then I assemble the pot and put it on a small gas stove (half the size Mr Hoffmann uses) on low heat. I buy ground coffee from a coffee store that grinds especially for moka pots, that means that it is thicker than espresso. I also noticed that if my pot is slighty wet (I always shake well the pot if it hasn't dried from the last washing) the taste is sweeter, less acidic and with stronger aroma. don't use fine grind, it blocks the brewing and tastes awful. I hope you try my method! I perfected it during 30 years of using this 3 cups bialetti.
@@Gotholia I also use low heat but don't know exactly when to turn it off. I just pull the moka out of the stove when the burbling starts but maybe I should turn off the heat before? maybe while brewing?
@@ricardozapata3728 I keep a small cereal bowl with a little cold water, by the stove and when I hear it gurgle, I take the Bialetti off the heat and submerge the base into it to stop the brew. I pour the coffee into a warm, empty cup (I'd warmed the cup with boiled water whilst the Moka is on the stove and emptied it as the moka starts to brew before I pour). About two or three pours will get the full amount as there's still that little bit extra to get out. Pour, upright, pour, upright. Hope that helps. 16g light roast, 18 dark. Grind not too fine.
This is amazing, thanks James! Even though my fav style is filter coffee, as an Italian I was raised among mokas ;) Two urban legends I am aware of two habits from my country and would be curious to hear your take on them:
* press the coffee before brewing (sorta of what you would do with an espresso machine).. in theory, this would make for a more "espresso" taste.
* keep the lid of upper part open at the beginning of the brewing, and close it once the first coffee starts to come up, while also turning the heat off.. for a more rounded taste.
While the first doesn't really hold in my opinion, with all the testing around temperature and pressure in your tests, maybe the second would make a difference?
Anyway, keep up the great work!
Second one, I'm curious how you can tell if it's done? Maybe looking out for steam where the pour hole is that it gets more steamy?
He cautions against tamping when he talks about the moka pot in his book the World Atlas on coffee.
@@rabidbasher yes everyone does, but why? Lets find out?
For your next video, I would be really curious for you to explain the differences of technique between a 3 cup moka pot and a 6 cup moka pot. I own a 2, 3 and 6 cup moka pot and I find it relatively convenient with the small ones to produce nice coffee. With the big one however, it seems incredibly difficult to brew coffee without getting to the wild spitting phase way too early in the process. I am excited to see what you do and how you can possibly avoid this to happen and get enough liquid through before the wilderness starts :D
Yes. I've struggled with adjusting the technique to the various size pots too. The smallest ones are the most fidgety to work with. :(
Couldn’t agree more. I find the 6 cup impossible to manage…I have the tiny single shot moka which is actually pretty good.
I have this same problem. I get consistent results from my 3-cup, whereas my 6-cup works so poorly I wonder if it's somehow defective.
Any suggestions for the 6 Cup moka? I have a 4 cup right now and am thinking about getting the 6 Cup Coffee Gator Moka. Have you found a method to better heat management with the 6 Cup moka? If you lost your 6 Cup moka would you replace it? Thank you 4 your help.
I love the "nerdy" stuff here. Please do more of these. I tried my moka pot with the filter and it did definitely create a different taste profile. Also it brewed differently as it didn't have the initial foam at the beginning, but came around half way and lasted to the end. I have always knocked the temp down to the lowest setting after the initial brew, but this time I had to keep it up more as it wasn't coming out well with the filter. I will try again with the filter and see if this is repeated.
Thanks! I’ve struggled with the moka pot in the past, to the point that I eventually gave up using it altogether for an aeropress. With these tips I’ve brewed good coffee with my moka pot all weekend. Plus, as someone who teaches Arduino at a college this video has given me the motivation to create my own frankenmoka….
I have observed that adding an aeropress filter dramatically decreases sputtering. It also produces a cleaner taste imo
Super interesting! Really want to try it now haha
This might be helpful for larger moka pots which seem to sputter much more easily
James, another superb video!
I have been using a moka pot as my daily for about 8 years now, and found it much easier to get a more consistent (and hands-off) brew using the method you referenced. 👇🏽
This is what works the best for my sealed-top electric range, which has a small element the size of the moka pot base:
1) Measure and add cold water to the base, heat on high to a boil
2) Turn element down to 4/10, remove base from heat, add coffee
3) Screw on the collector, replace about 1/8th of the base (depending on roast and grind) back on the element
*No sputtering, no scalding hot collector, no high-acid profile, and a well-textured, nuanced brew*
Here's my setup:
Moka Pot: Ilsa Slancio 6 cup stainless (this is an older model that has very thick stainless)
Coffee: ~30g
Water: 400-430g
Good luck with your own tests everyone!
As a newbie I had to replay more than I care to admit but there is a tonne of useful advice here - many thanks James! Wondering what else I might glean in the next episode - outstanding work!
The specific heat capacity of aluminum is 0.89 J/gK, and for steel is 0.47 J/gK. So each gram of Al is storing twice as much heat as a gram of steel, at a given temperature. That almost certainly has a lot of impact on your thermal imaging results. It'll also influence how removing the heat source affects the brew: an Al base will have more residual heat to give the water.
We could also analyze the moka pot as a heat engine for raising water from the lower chamber to the upper, to get an idea of how many joules we need, at minimum, to complete the brew. At 15cm of height difference between the water and the top of the tube (a total guess; measuring would be better), it should take about 0.24 J to raise 160g of water, once the system is hot enough that things have started moving. Not much, compared to the thermal mass of the base. So I think mostly, once the first drops flow, you just need to keep the base from cooling down (losing heat to the air in the room) to complete the brew. No need to add any significant additional heat.
So you are saying I should insulate the base of my moka pot?
That is if both pots weigh the same, but they most likely dont.
As the specific heat capacity, it's probably better to use the volumetric heat capacity since the wall thickness are similar rather than the weights of the system.
To rehash what @KJ Dude said, specific heat capacity is per gram. Aluminum has a specific gravity of 2.7, while steel is 7.9. So a given volume of steel will store _more_ heat than the same volume of aluminum. That being said, the steel moka pots I've seen have walls much thinner than aluminum ones (mechanical strength/cost is likely what drives the design). So, in the end, to know which pot has more thermal capacity... you really need to weigh them and multiply for the specific heat capacity.
@@daniloxyz Best answer to this thread yet. Totally agree.
I'm so glad for this video because all of my moka pot brews were inconsistent and I couldn't understand why. I would do the "exact" same thing and the still weren't consistent so thank you for the mind blowing insight
Million of people : making Moka Pot coffee is easy
James : this is such a fussy frustrating things
😍😍😍😍
I think some of the finicky nature for James is his use of light roast specialty coffee. Most of the millions of people using the moka pot are brewing darker roasts. They have also never uttered the words " mouth feel". Traditionally in my Italian/American family, "black coffee" is an after dinner coffee made with a moka pot and diluted. But while diluting it with water is good, diluting it with Sambuca is way better. And by diluting I mean a 50-50 ratio. :-)
Millions of people easily make mediocre coffee in the moka pot daily.
James is right. Even when you get your technique nailed down, they can sometimes just have a bad day and channel, or spit, or whatever. Occasionally frustrating.
Thank you! I always wondered what exactly causes this sputtering at the end of the brew. I tried the "the wired gourmet" method a few times, but was always struggling to keep the flow rate low enough to reach 3 Minutes brew time. And it always ends up sputtering.
Its great this Mokka Pot topic finally got some attention. There are about a million videos about a dialing in your grind size for espresso but (including this one) only two usefull videos about brewing with a Mokka Pot.
My recommended workflow if you use your Mokka Pot for camping: Boil the water in the lower part of the Mokka. In the meanwhile you can grind the beans and fill the basket. When it's about to start boiling put the filter in the pot, screw the upper part onto the pot lightly, put it on the floore where you can fixate the pot with your shoes. After applying the correct amount of torque bring it right back to the stove. The downside is that most people will give you weird looks. But being acquainted to that will make your life easier in general so I count that as a plus.
Gee, I always thought the angry sputtering was the POINT! The announcement... YOUR TRAIN is pulling into the station... your hair flies in the shockwave! Having been introduced to the moka pot 20 years ago, I never went back. Thank you Bialetti! And thank you James for this really informative vid! I too prefer my steal pot, but the aluminum has it's charm. I think it's definitely SWEETER somehow. I won't be bying a heating plate but I will be practicing removal to get max fluid.
There is a rod stand that fits over a gas hob that's designed specifically to hold a Moka pot. It may have enough thermal mass to add enough heat after the gas is turned off. Just a thought.
As a researcher watching this video, brings me so much satisfaction from rigorousness this man is putting in and at the same time starting to doubt whether I put enough thought to my actual scientific experiments!
hello colleague 🤓
He wasn't kidding when he warns us that this video gets very, very nerdy, it really, really does get very, very nerdy.
Never imagined that I would watch 32 mins long, nerdy video about coffee. And it is 1 of fourrrr :) good work really
I really appreciate this research! Not many people (if any) have put this much time and effort into researching this, and released it to the public. We all know more about Moka pots because of your work! 😊
The induction plate discovery makes me think there's an opportunity to build a different bottom section for the moka pot with a heavier metal base. That way you can cut the heat entirely and the base retains enough heat to maintain the rest of the brew
That might be what's happen with the "stainless steel" version since Hoffman writes on the screen that the top portion is not stainless steel.
@@confusedwhale I was very surprised by that caption saying that the top section isn't stainless steel. I have that exact pot, and the top section definitely looks, feels and behaves exactly like stainless steel. Plus the product is described by the manufacturer as "stainless steel", and I believe them.
fully cast iron XD
I've been thinking for a long time that I wanted a moka with a thicker bottom and a deeper milling in the center around the basket's tube. Would likely make for a steadier brew temperature with less wasted water left in the bottom.
@@richardemerson8075 same, I have it too and I'm pretty sure the top *is* stainless steel
I'm not sure if someone else mentioned this but you can change the emissivity setting on a thermal camera to account for the reflectivness of a material. It is normally set to around .95 for non reflective materials. Set it lower for more reflective materials. Love your work! You've taught me quite a bit over the past couple of years :).
This was a fantastic video. As someone with a background in infrared imaging systems, my heart swelled when you got to, “so of course we then had to rent an expensive thermal imaging camera…”. Honestly, I’ve been diluting my Moka pot brews for years for that better balance with my own preferences, so it was good to see that you found that helpful as well. I’m really looking forward to experimenting with temperature control and diffusion now, because we bought some Cometeer to try it out and now I’m torn between the obviously superior flavor balance of the Cometeer and the more full-bodied texture that I love from the Moka pot.
Judging from the image quality, that certainly was an expensive camera. I have a FLIR camera, and the resolution is nowhere near that good.
This is why this guy is the best here on youtube for coffee no stupid gimmicks or zoom shots / nonsense , pure class content, thanjs james us nerds are grateful
James you scientifically explained exactly what I found after 2 years of experimenting with my Moka pot. The one thing that is absolutely correct, these pots are finicky. Every little change you make changes the brew dramatically. Thanks for showing the data.
As a nerd, physicist, and daily moka pot drinker i love this!
After waching this i have been playing around using much lower heat than what i used to do. Doing this i found that on my induction stove (with seemingly stepless adjustment) the lowest heat will make the brew slowly stop, i.e. the temperature in the bottom chamber drops to a level where the pressure is not enough to force water through the coffee. This means that there is an setting (in the upper end of whats presented as 1) where i can make the water flow nice and slow, and keeping the water in the bottom chamber below so low that it never sputters, in the end there is just steam. This completely elinimates the harsh tastes from the high temperatures that you record during extraction.
During these experiments i also figure that i expect the cause of sputtering is not steam comming from the bottom chamber, but water that is so hot that it is still above boiling poing after passing through the coffee and filter. In the bottom chamber and in the puck there is an increased pressure that will keep the water from boiling, but in the tube in the top part there is not, so any liquid that will get to the tube with temperatures above boiling point will instantly boil, causing the sputtering.
Have you seen the video of James using a centrifuge on coffee?? It's great, you might like it. 👍
While it isn't something I've seen in domestic stoves, a temperature controlled hotplate might be your next step in experiments. They're often used in chemistry labs, and if you use one and set it to 100°C, the water shouldn't rise above that temperature. You did test with boiling water, but this would allow for higher temperatures as well.
This functionality is something I really want to see in induction stoves, as it would be brilliant for so many types of cooking.
Some very expensive induction stoves do have that (cheaper ones too but I don't really trust them). If I recall correctly they even have connection for a probe to stick inside the pot or whatever (haven't seen a cheap one with that).
I was thinking of a self heating electric moka pot that could regulate the amount of heat it pumps into the water based on the steam temperature measured at the top of the base. A well-tuned PID controller could maintain a very even steam temperature. Maybe this could be the next generation of moka pots (if it doesn't already exist)?
The temperature of the object being heated can rise above the temperature of its heater if it gets heated up faster than it loses heat. So if your insulation is good enough you can definitely rise above the temperature of the heater. Moreover the temperature of the heating plate does not correlate linearly with the temperature of the water inside a moka pot, what matters is the rate of heat transfer so that doesn't give you much control. It does give you some more control over the gas stove but only because it essentially gives you a lot more granular power input setting. What you would need is to somehow control your power input (the heating of the moka pot) based on the temperature inside the moka pot (either the water or "coffee bed" temperature).
@@InTimeTraveller Sorry but that's not how it works. Yes, if it more heat flows in than out it will heat up, but heat always flows along the temperature gradient from hot to cold. So if the heater really is temperature controlled, the pot wouldn't get hotter.
@@FlorianLinscheid the temperature of an object is but an indication, a metric of the thermal energy it has stored inside. The surface temperature of the heating plate is an indication of the energy it has inside, but it's not the only path of energy transfer. For example when he lifted the pot off the plate it kept getting hotter because energy was still getting supplied to the pot via radiative heating and convection and it couldn't lose that energy to the environment fast enough. Rate of heat transfer between the plate and the moka pot and between the moka pot and the surrounding environment is what is going to determine the actual temperature of the moka pot. Especially since we're talking about a timescale of two to three minutes.
Temperature gradient does affect rate of heat transfer but it's not the only variable. It's just like voltage in electric circuits: you can temporarily charge a capacitor to a voltage higher than your supply voltage and that's the entire concept behind boost converters. Voltage is similarly an indicator of the energy stored in the system and electrical energy does flow along a voltage gradient as well, but the rate of energy transfer (current) together with the total energy are going to determine the instantaneous voltage at any point in the circuit.
having trouble sleeping so going to play this and doze off to the sweet elegant sound of James Hoffman narrating his mental breakdown
I found a couple comments made in this video very helpful - the bit about pressure increasing temperature, and too high of both being the cause of sputtering. I'm quite new to decent coffee brewing, having just gotten an encore a little over a month ago, and moka pot is my almost singular brewing method. However, I've only been working with fresh beans for the last few days, and due to the Co2 release they behave SO differently from the much older beans I had been using before. Using my old technique on fresher beans was causing my moka pot to clog up and produce very bitter brews. I had a vague idea forming of how the gas release must be affecting the brew but watching these videos clarified it for me - I can visually see the gas release is temporarily retarding the brewing process, so that must cause a build of pressure and thus an increase in temperature, and as Mr. Hoffmann explains that would be a clear cause for the crazy bitterness and sputtering I've been getting. So this morning I tried a lower temperature, and magic! It works, it flows, and way smoother! I had only ever used much older or pre-ground beans so I just didn't understand what my moka pot was doing, but now I feel like I've learned more about the dynamics of this deceptively (not so) simple little brewer. Thanks so very much for the assistance Mr. Hoffmann! Really appreciate it.
I love this breakdown and appreciate all the hard work you put into this!
You know it's gonna be great based on how many times he said "and I'll come back to that later".
I haven't pulled out my Moka pot in a few years because it was frustratingly inconsistent and takes a longer amount of time and attention, but when it was good, it was great! I do miss the little guy.
James: “Warning. This video gets very, very nerdy”
Cousin Avi: “I know. That’s why we’re here”.
Fascinating video. Other things I would like to see tested are - the effect of lightly tamping the coffee to create more resistance, aeropress filter in the base of the coffee basket for more even flow of water, replace filter with E&B competition filter and pre-wetting the coffee bed with cold water to reduce brew temps.
I even fully tamp (like espresso) at this point and get way better extraction that way. Gotta have that coffee filter tho in the base of the basket (!), otherwise you get a ton of channeling...👍
Very cool experiments as usual James! Although the thermal camera part isn't very scientific as aluminum and SS have different thermal emissivity. The shape of the pot also matter as it determines the air flow around the pot thus heat distribution.
The paint used on the strips he measured will have the same emissivity so the temperature readings will be fine. Emissivity is only a surface property, not a bulk material property. The only question is what emissivity he used (should be .91-.95 for most paints).
As someone involved in research I can really appreciate this, it takes a lot of time and effort to set this up. Us viewers are all appreciative of your in depth dive into this now modern classic coffee making method. I hope you and your team actually manage to publish some of this @James. The stainless vs aluminium was what I was waiting for in particular. There is an art to getting a good moka coffee, always seems as if a bit of luck is required.
Wonderful video. Exceptional patience for James at his best. I look forward to episode 3.
Putting the water added at the end in the upper pot instead(prior to brew) keeps the temp down on the grind and smooths out the spike in temp at the end, other than that this was friggin awesome!!
Awesome. Thanks for the suggestion!
I’d be curious to know more about how the amount of coffee you add to the basket influences the brew (taste especially). As a Southern Italian, I was taught to create a “little mountain” of coffee in the mountain (without pressing coffee down), but I know in other parts of Italy they’d put way less coffee in (like you showed). Would you test this further?
J probably doses by weight than volume.
i.e. If you grind coarser then it'll fill the basket a lot more than a fine grind.
I have a Brikka version of the Moka pot so it added additional pressure to the system which make it tricky to “control “ the pressure. I use 17g of medium roasted coffee with hand grinder at a very fine setting. Hopefully James will get to the Brikka soon.....
@@Weeem good point, thanks!
I think it could be interesting to look at the design of the lower chamber. Does more or less airspace at the top mean higher and lower brew temp because it's more area that needs to get pressurized? Does lower chamber design dictate how the water raises once heated? Space vs mass of water vs surface area (tall and narrow vs wide and low)
Also, a larger thermal mass could be interesting to experiment with, like a larger steel plate that would heat slower and lose heat slower.
An add on to this would be noting how the placement of the pressure valve (if indeed you shouldn’t fill above it) restricts capacity and impacts the ratios you brew with
This is a really good thought. I could see using a side chamber with a bladder, or sprung piston to have a reservoir of pressure to remove it from the heat but continue the brewing.
I'm very excited because I've actually used this same exact induction plate method for months now (as I got the inspiration from wathing Wired Gourmet and the slow brew he presents) and it really works! Thank you James for one of your best videos!
I’m just happy that future generations will have this information available.
Hey, James. This video is truly amazing for understanding what's going on in moka. I have an idea for better heat accumulation, maybe you should place moka in a pan with sand, like a cezve in Turkish coffe making method. It has really large thermal mass. So you heat the sand, cut the heat from stove and place moka there.
I was thinking you could heat it on a cast iron pan. Those tend to retain a lot of heat as well
Thermal engineer here! To answer why the Aluminum moka pot is colder than the stainless steel one: Specific heat is a thermal property measuring how much heat can be absorbed into a material. Think of it as a sponge. Aluminum has a higher specific heat than Stainless steel (921 J/kgK vs 502J/KgK). This means that for the same amount of energy put into the aluminum vs stainlss steel, the aluminum will "soak up" the energy better, and have a lower temperature rise than the stainless steel.
The biggest revelation for me in this video was the overheating and sputtering. Now I get an evenly extracted clean brew every single time through preventing the water from from steaming inside...
I have three (3) Moka pots and I have struggled to create some systematic around brewing to get a decent cup frequently. Now the biggest problem is solved.
Off to coffee heaven!!
Ps. This is easily the best video on TH-cam, and I will be forever greatful for your input for the Coffee community.
It is very satisfying to hear how finicky these are. I have had so many extremely delicious coffees from a Moka pot and even more horrible bitter ones. I have a love hate relationship with the pot because I'm convinced it is capable of making a delicious brew but have had enough bad experiences that I keep trying different methods for brewing. This was a very enlightening video on the subject. Thank you so much!
This is one of my favorites of all your videos. Really interesting, and I always appreciate your honesty and humility when the data teaches you something.
Regarding the termal imaging portion: The first thought that comes to my mind is that the steel pot likely has much thinner walls than the aluminium one, so even though aluminium is a better conductor, the steel has far less thermal mass to heat, which is why it heats quicker. This would also explain why the cooler brewed coffee shows through the thin walls much more quickly.
That’s a good input. To add to it, I think the geometry plays a role here as well, with the wider base of the aluminium pot shielding the hot air better than in the stainless steel pot. To support this, I think it is noticeable that the heating in the SS pot starts on a localised, isolated spot, rather than continually from the bottom up.
Thermal imaging also varies based on thermal refraction factor. He's seeing different depths of heat here because the material thermal refraction properties are different.
Hoffmann mentioning my idol "The Wired Gourmet" made my day! I gotta admit, his technique for Moka Pot made my coffee way better than Hoffmann's and now he's kinda "recognizing" it with scientific data. What a great tool TH-cam is! Coffee brewed to perfection !
I was surprised you didn't look at the amount of coffee used as a variable. I'd imagine that less coffee would both reduce extraction as there is less to extract, but also pressure, as there is less coffee to press against. What would be the recommended coffee to water ratio?
Absolutely the best, most scientific, well elaborated, classy approach to the moka pot. All the answers to the questions we didn´t dare to ask! 😆
I tried this method with a ribbed cast iron skillet & didn’t get any sputtering at all!
I tried it with the recommended method:
• Stainless steel moka pot
• Good quality fresh ground coffee
• Boiling water
Heated the moka pot on a HOB with a cast iron ribbed skillet as the heat shield.
Came out delicious! Not over extracted. Nice sweetness.
This setup kept the moka pot on a slow pace and never went further (no sputter at all). Perfect!