Why Are Those Trays In Microwave Ovens?
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- เผยแพร่เมื่อ 28 ก.ย. 2024
- Ruminations on the ubiquitous microwave.
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This makes so much sense to me now.
I can confirm this used to be a problem!!
My mum had exactly this experience with a late 70's early 80's Rank Arena microwave without a turntable.
She heated a mug of water to make her coffee one morning, as soon as she went to take it out of the microwave, or she may have just put a spoon in it to stir the water, the water instantly exploded.
Luckily she wasn't seriously burned, she must have had super fast reflexes, and the roof of the microwave took most of the hit😲
The phenomena you describe is called thermal nucleation, IIRC.
I had that happen in a way with Soy Milk and I think from memory I was getting the cup out by holding the body of the cup and it was very hot plus some splashed on my hand, I just threw the cup back in the oven and made a mess of course. I had a pot of water sitting in the sink and was able to dunk my hand into it, but it still burned and hurt a lot.
@@goodun2974 Yes, I think you're right. As Fran said, I rekon the mug must have been very clean, (my mum is a bit of a clean freak) and must have had virtually no scratches or pits etc for nucleation sites to form steam bubbles.
In the 70's I was at a snack bar at an Air Force base and heard a loud pop and a scream. A guy bit into a peeled hard boiled egg he'd heated in a microwave. He got hospitalized with stream burns in that mouth and on his face.
Speaking of egg's when my parent's were away (many Moon's ago)my Brother and I thought it would be funny to put an egg in whole. We put it in a sealed Tupperware container and sticky taped the lid on and it exploded alright and there was yolk like powder in there and took us ages to clean. It sure smelled as well, I can imagine what happened to the guy above.
There's a video out there where a comedian called Jack Dee would microwave eggs with peoples faces on until they exploded. All fun and games until he got one that blew the door open. Quite amusing but shows the power possible.
I seem to remember back in the seventies when the rotating platter was being introduced, microwave oven manufacturers claimed it was added to more uniformly heat the item with no mention of it being added as a safety feature to eliminate the dangers of superheating.
Our 1970s microwave did not have a carousel. Every one I've used since has had one. I always thought it was to ensure even heating, but the lawsuit angle makes much, much, much more sense. Thank you for reaffirming my cynicism, Fran!
Functionality < liability.
it helps with more even heating as well
I gues its 2fold
Fun fact, in the Netherlands, where Philips introduced the first domestic microwave ovens, they were branded/named after the microwave tube in it, the magnetron. Hence, in contrast to just about every language where its name is a translation of micro-wave (oven), in Dutch the appliance is called a magnetron.
As another commenter remarked, I also remember there was a second reason for the revolving plateau, the standing wave pattern that forms inside the microwave oven creates uneven heating, so one could end up with for example meat that was well heated/cooked in spots but cold and raw in other spots, which could cause problems with bacteria or parasites that were not killed, leading to infections or food poisonings.
I always thought it was to prevent hot and cold spots in food due to standing waves inside the oven. I've seen microwave ovens with a rotating reflector at the top of the oven which I thought was a clever way to prevent standing waves, or at least stir them around a bit.
I'd say it's more so this. You can do an experiment with a vertical grid of neon indicator bulbs standing inside the chamber without the rotisserie to visualize where the RF nodes are, some will illuminate bright others will be dim or not illuminated at all. With the rotisserie you can see how more of the food or item will be evenly exposed as it rotates.
Same here. Interesting. Fran teaches this old brat again.
@@_BangDroid_ you can also do this with uncooked poppadoms
What I have always heard is that microwave ovens used to use rotating vanes to prevent standing waves, but switched to carousels because they were cheaper to make. Vanes are supposedly better and many commercial microwaves still use them.
@@null2405 Do you read "What If?" too?
Hi, Fran - our new Panasonic microwave doesn't have a turntable, or rotisserie as you call it. I could be wrong, but I understand that it's a relatively new design in which the antenna itself rotates under the flat bed of the oven.
That's a flatbed design. They're supposedly better, they often heat from below as well which creates convection currents.
It's not new. Been around since the 1980s. I've had many, including the latest one I have from Whirlpool, MWF421.
As I wrote in another post, I believe Philips microwave division were among the first to use it, maybe they even pioneered it (they were later acquired by Whirlpool).
FYI, many “flatbed” microwaves just have stirrer vanes under the floor.
That's an _old_ design.
Here the recipe for a superheat water that worked for me.
I discovered it by myself a long time ago. As I was testing the brand new first microwave my mum ever get, I found fascinating to see water boiling "by itself"
So I put a coffee cup half filled with water nicely centred and start the microwave to see it boil.
It usually take 40 second and after seeing the bubbles I stopped the microwave and let the cup inside.
I do this a couple time, this allow the dirts (calcium) to sit at the bottom of the cup and thanks to the closed door, no dust fall in.
Just before bed I give a last try, but after 50 second (it was an electronic digital control with count down) the water wasn't hot enough to boil. I was afraid to have broken the brand new microwave just by doing this multiple time.
My nose was stuck on the door when the steam explosion occur seconds later!
The amount of water was low and the superheat not to high, so no damage as all stay into the microwave, but what a burst !
So don't do it it can be really dangerous, and if you do, (as I know some will) put only a small amount of water like 12 millilitre of water (size of a ristretto) to limit the power of the burst, and if nothing happen let it cool, never try to poke it and don't apply heat more than 50% it take to boil (if it boil in 30 sec don't go further than 45 sec) as the energy put over the boiling temperature will be liberate in microsecond, it can be really powerful even blasting the door open. Even with these precaution it's dangerous, again let's someone stupid do this !
It happen by accident, and never did it again after knowing what happen
My first microwave oven had a warning somewhere in the manual along the lines of "do not re-boil water inside the oven".
@@MCPicoli maybe this is where the rumor that twice boiled water is bad for you?
Bravo Fram, Bravo!
- Please, go ahead and take bow...
- - To recognize and acknowledge my applause praising this video.
I remember the very first Radar Range I saw...it was in 1966 in the kitchen of a wealthy family in Oahu whose dad was a scientist working for Raytheon. It blew my young mind. I remember this as if it were yesterday.
I had heard a couple of times, maybe in the 90s, of liquid exploding when taking it out of the microwave. However, I never knew of it happening to someone I knew, or in my house. So after a few years I kind of just forgot about it and in the back of my mind took it as a kind of urban legend. I always thought the rotating plate was purely for even heat until now. We got our first microwave around 1978 as well. At that time no one I knew had one. Couple of years later lots of people started getting them.
My parents got an Amana Radarange around 1980. I remember it being the first time I saw a membrane style keypad. It had a heavy glass dish that sat in a recess in the floor of the interior and the rather unusual bottom hinge door.
Are you sure that they were membrane? I think they were capacitive touch.
A similar phenomenon: Supercooling, where very pure water in a very smooth container will remain in the liquid state even if the temperature is under the freezing point. Then, a slight disturbance will trigger the cristallisation, where all the water turns to ice in a few seconds.
I’ve actually experienced this first-hand. Literally. It was a cheap-o brand microwave, don’t remember whether the table was just broken and didn’t spin or if it didn’t have a rotating tray or what. But I was heating up a plastic cup of water, and when I reached in to grab it - it went absolutely nuts. Started boiling vigorously right as I grabbed it and spilled over the edges burning the backside of my hand. Terrible experience. 1/10. Do not recommend. At the time I wrote it off as a freak accident, justifying it that perhaps it simply started boiling at the very moment that I opened the door. One of those “perfect timing” type things. Turns out it’s even weirder than that. This is actually really cool. I mean the scientific reasoning behind the occurrence. The more you know. Thanks for this nugget of knowledge!
whoa - it would seem like this should be grade school science - evidently, not so, at least during my school years - - I'm in my 70's and have never heard of the "surface tension / super heating" phenomenon before - - fascinating - - thank you Fran.
We bought a Radar Range for Mom in 1969. I still use it today. Only repair was the light bulb. We had to license it with the FCC as a transmitter of some type.
My Parents had the 1980 version of this Amana. It had a fantastic "touch control" keypad, much like those sensitive touch-dimmer switches of the 80s. Worked great! Had the 1/8" jack for the "temperature probe". Since that era, I despise every lousy membrane keypad on basically ALL modern ovens, despite other improvements.
My rich neighbors had a Radar Range in the early '60s. It broke, and they didn't have anyone on the west coast to repair it. They would have had to pay for someone to fly out to fix it, or ship it back. My dad was a physicist, and I remember him and one of his colleagues taking it apart and fixing it.
I bought a Litton microwave in 1978 for $649. I remember because I was making $3.50 per hour at the time. It had a waveguide over the top and stirring fans on each side. It cooked very evenly.
Will add that the superheating takes place in the bulk fluid, making a volume of fluid that, is going to get hotter and hotter, as the microwaves set up a standing wave in the cavity, so this pattern does not move around much other than jitter at mains frequency with the FM modulation of the basic microwaves. thus the turntable, there to ensure the food is stirred through the pattern, so all parts will get more or less even heating.
Incidentally I have a microwave with no turntable in it, it has a flat glass rectangle in it as base, but up under the roof is a large plastic microwave transparent window, which has inside it the waveguide outlet, and as well a stirrer fan, driven by the airflow over the magnetron cooling fins, which turns this light steel blade around, so the microwave radiation pattern in the cavity gets swept around, instead of the turntable and static wave pattern. However the blade is a lot more complex, and takes up a lot of room in the roof, and needs a big plastic cover over it, so the cheaper option of the round turntable, with the pancake motor to turn it, won out, as that is a lot easier to scale up in size, and the rotation does result in more even cooking, as the radiation pattern in the centre of the oven will be more even that at the edges.
First microwave in the family was around 1979, when Dad brought home a brand new Sharp convection microwave, which, in addition to having an all stainless steel interior, also had a convection oven element in the cavity, and a microwave oven built in, so you could do things like cakes, where the microwave did most of the cooking, and the convection side would result in a perfectly browned exterior of the food, be it bread, cake or a roast. Biggest drawback was that this was also "self cleaning", which was actually the roof being made from coated mild steel, and this rusted out. Not a problem, my father ground off all those spot welds holding the top on, and fashioned a new cover for the top of the cavity, made from stainless steel perforated plate, welded in to the existing cavity walls, and then the heating element assembly, along with the new non rusted convection fan, was screwed back on top of it.
I currently have a regular small microwave with turntable, but also a 1980 made KIC microwave, with no turntable, and the aforementioned stirrer, that has done sterling work over the years, a great buy for the $4 I paid for it as a beige and brown box on auction in the 1990's, and it is still going strong. Small one is heavier than the big, as it is made with actual steel plate, not the thin foil of the new ones, and has a power transformer made with real copper windings all over, not the undersized and CCA wire the current ones use.
It's more about the standing wave hotspots. Superheated water can happen with the tray, too, but less often. The container needs to be very smooth, water very pure, etc.
I didn't know about the rotation. But a borosilicate tea glass once exploded in my microwave oven despite being rotated. The door flew open with a bang, no one was hurt, the microwave oven was not damaged. And is still working properly. It is made in the UK and has been in daily use since 1990. I think the delayed-boiling explosion happened to me because I first brought the water to simmer and then heated it again to get it a little hotter. By simmer, the water was gas-free and could overheat, even to the point of exploding. It is better to boil water in an electric kettle, which uses almost half the energy of a microwave. Microwaves are ideal for heating food, milk and the like.
My parents had that Amana Radarange Fran shows the manual for. Worked great for decades. I once in my current modern microwave oven that has a carousel heated up a cup of water for some tea. I heated it for 5 minutes not realizing 2 to 3 minutes would have been enough. I opened the door and the water was not boiling. I dropped the teabag in before taking the cup out. Good thing I did the teabag first because as soon as the teabag hit the water the water boiled like crazy and half the water boiled over instantly. No explosion just an instant raging boiling. I can only imagine what would have happened had I microwaved for 10 minutes.
I grew up with one of these Amana RadarRange's. My parents taught me to heat it slowly, & periodically move it around & check the temperature.
Back in the 80s we had a Nordic Ware Micro Go Round in our microwave. It helped even out the heating.
I don’t agree with your conclusion. Turntables were put in to replace spinning wave guides. It was the cheaper microwaves that got turntables first. Eventually most microwaves got turntables as a cost-cutting measure. Very expensive commercial microwaves have no turntable even now.
I love all of your videos ! Perhaps one day you could explain why microwaves have a metal rack in them. Mine has one that's above the carousel. I always thought you couldn't put metal in the microwave.
I remember my mom talking about this phenomenon! Once when I was a kid, I don't remember what brought it up but she described superheating to me (without actually calling it that), and I remember wondering how one would actually achieve that particular set of circumstances. On a possibly related note, this was around the time my folks finally replaced their old flat-bottom microwave for one with a rotisserie in it...
Stale donuts can be softened by a short time in a microwave, but that is a common cause of burns when doing that with jellied center donuts - the central jelly, insulated by the donut cake, gets much hotter than the exterior of the donut.
The jelly in the center heats up faster because of its water content. Water being a polar molecule is more susceptible to heating by microwaves.
Back in the 70's, Heathkit made a microwave oven kit. I vaguely remember it being included in a Consumer Reports' review of microwave ovens, where it got a rather mediocre rating.
Superheating is also a problem with tank-type water heaters. The relief valve on top of every tank water heater is pressure and temperature sensitive, and without it, a tank water heater can become a quite powerful bomb. The boiling point of pressurized water is higher, and even the aqueduct pressure is enough to raise the boiling point a little bit. Now assume a tank water heater without relief valve, with a defective thermostat that allows the water inside the tank to get above the boiling point... Everything is fine until someone use hot water... The pressure inside the tank suddenly drops, therefore all the water in the tank instantly turn to steam.
The original microwave oven was the size of a refrigerator and used 6,000 watts. It would over cook a hot dog in less than 15 seconds. It sat in the kitchen of one of the executives for decades and was still working. Finally after his passing the wife wanted to remodel and tried to get the company to come and get it.
My first microwave oven was a Philips in the late 1980's and none of them had any rotating bottoms, still heated very evenly. Manufactured in Sweden at the time (Norrköping). I bought a new microwave 2 years ago, no rotating platter, just a smooth glass bottom, still also heats very evenly. Before that I had a Panasonic with rotated and that was a great oven, but not any better than the one I have today.
As I understand it all these models (even the first Philips ones), have hidden rotating deflectors which spreads the microwaves evenly inside the oven. Some models even have two, at the top and the bottom for even better results.
The thing that all such ovens have turntables to avoid superheating must be an American phenomenon (people suing companies frequently?) because where I live we always had both types up until this very day.
I recall my parents buying their first microwave in the late 1970's and part of the sales price was a night class cooking lesson to learn how to actually use it!
Over in the UK once I heated 2 cups of water in a Pyrex measuring cup in my microwave. It beeped, I opened the door, and there were no bubbles. As soon as I touched the handle the water erupted. Scared the h*ll out of me!
great explanation Frannie, I also remember our first 70s MW was huge & stationary, we later added one of the wind-up turntables that were popular during the transition. The built in carousels were much more convenient..
We also bought one of the wind-up turntables for our microwave in the 70's. Good times.
Early microwaves had a mechanical shutter reflector system in the waveguide to spread the waves evenly over the food.
More expensive to get right than just rotating the food.
Also shifting the waves means more usable space in the rectangle shaped oven.
I notice that turntable, like in every microwave I've ever used, has a slightly jumpy motion, and I'm now wondering whether this is why - extra stirring effect. Or just an odd turn mechanism?
BTW, mine is the one kitchen that doesn't have a microwave, but only because my present studio flat is tiny, slightly smaller than the main FranLab room. Thinking of getting a much stronger shelving rack so I can have one again.
Bumpy turntable is down to cost cutting, as the originnal turntables used somewhat decent bearings for the table, and a motor with a moderate amount of torque. The modern one is a lot lower torque, and the bearing wheels are now an injection moulded and mostly unfinished thermoset resin, so they have somewhat uneven turning, and the tables themselves are also wavy, poor control of the moulding, along with a stamped cavity floor that often is warped, as it is made from thin steel, and the die set was both made for thicker steel, and is well worn.
tiny kitchen I have never seen one too small to fit a microwave in, the smallest ones are 20l, which is the size of 2 loaves of bread, and even caravans that are pop up come now with a microwave as part of the deal, as they can be small but useful.
So your telling me a modern microwave with a burn out rotisserie motor suffers the same fate. That explains some weird blow ups I have had.
No microwave oven in my house. Nope.
I remember my mother had a radar range , she used it to store pots and pans LOL !
Heating water in a microwave seems a very American thing to do.
Yes. Because it is the most energy-inefficient way to boil water. Americans celebrate the most energy inefficient and carbon intensive way of doing things. It pops up everywhere, from microwaving water for tea to water glasses filled bottom to top with ice in restaurants. Think of all the energy used to make all that unnecessary ice.
@@franklittle8124 no wonder, they threw all the tea in the river. Didn’t invent microwaves yet.
@@franklittle8124 I suspect that boiling water in a pan on a stovetop is less efficient than a microwave. My 1985 Amana is around 50% efficient (just slightly better than its competitors at the time) . For 1000W of heat put into the food, it consumes 1920W of power. With stovetop boiling I expect that you’d be sending more than 50% of the energy out as waste heat into the room.
O.K. I'm confused. You talked about the rotisserie, ( or turntable, as we call it in here the U.K., over here a rotisserie is a horizontal turning spit, usually with a chicken on it)., but you did'nt talk about the tray you mentioned in the title of the video ?
@@ralphj4012 O.K. That sort of makes sense. Cheers.
There are some microwave ovens appearing now that do not have a turntable, but instead have a pattern of angular bumps on the walls that are supposed to spread the microwaves around and prevent hot spots. But it seems like that wouldn't do anything for the superheating problem. Any thoughts? Are we going to see a resurgence of superheating incidents because of this?
Hot water can be bad, but steam, even at the same temperature, is spectacularly worse. I suspect many of you already know why, but it has to do with "heat of fusion" and "heat of vaporization" at the points where something changes state. In this case, water and usually at some nominal atmospheric pressure. For water, it is 80 calories per gram to convert ice to water and 540 calories per gram to convert water to steam. In the case of ice, ice cubes work so well because they absorb those 88 calories just converting from ice to water and after that the cold water absorbs only 1 calorie per degree C per gram as it warms above freezing. But steam has that massive 540 calories per gram. So, if you get steam on your skin, it releases all that heat just turning back into water. Steam at the boiling temperature is therefore vastly worse than water at the boiling temperature. These points are different at different atmospheric pressures (and for different substances). A common physics class experiment is to pull a partial vacuum and demonstrate water existing liquid, solid, and gas (boiling) at the same temperature in a partial vacuum. This is called the "triple point" where all three states are in equilibrium.
Fascinating science lesson. Thanks. ..another question: Why did they introduce the loose plastic ring with the wheels on which makes the rotary tray jump sometimes and spill the fluid or even worse, come off the spiggot and not turn at all, instead of fixed wheels in the base that were much more reliable?
people also assume all ceramic is microwave safe, but some are not. Some ceramics have paints or glazes with metallic ingredients. My old MW manual had a warning about Corning Centura & Corelle Livingware
I enjoy watching you! You pleasantly relate news and events and do so on *my level. Kinda like we are ole Jr High chums! Thanks for a great diversion from the humdrum, every day stuff. ps. love to hear you 🎤 🎶
my family first got a microwave in the mid 80s (I still have and use it), and not only does it have a turntable, but also a spinning mirror (behind a cover) in the ceiling to more evenly distribute the microwaves. This is spun by the air being exhausted from the cooling fan...
My first microwave was a flatbed with rotating antenna. One day smoke issued from it, so i removed the cover to investigate, no sign of burning. Scratch head, eh? I used to put three rafia mats inside it in a vain attempt at even heating. I peeled off the outer layers and the middle one was mostly charcoal. Problem solved. By this time, the price of microwaves had halved so I replaced it with a budget Matsui (with rotating platter), much better. Sadly the Matsui died, post mortem: the magnetron self destructed, it rattled when shaken. RIP Matsui.
For whatever reason all the professional kitchen microwaves I've used were flat bottom.
It's likely that these microwaves have something in it that would look like slow rotating fan blades made of metal. A mechanism that stirs the microwaves inside the oven to spread them more or less evenly. And I think professional microwave ovens shall be flat and easy to clean. And you can put in big rectangular dishes without having to worry about it jamming (like how it would happen in a microwave with rotating tray).
@@maxmuster3297 Interesting. Cheers.
I had a home microwave with one of the fan like mechanisms you mention.
There is one type of microwave I know of that doesn't have a rotisserie turntable: Commercial ones that places like gas stations have. I know this because my work place recently replaced all the ordinary microwave ovens with those commercial ones.
Thank you for the fransplaination. Stay safe
We had an Amana Radarange in 59. Along with a color TV.
This can still happen. Well it happens to me occasionally with cold coffee with milk and a small amount of sugar. I also put the cup on the edge of the rotating glass platform and not in the centre. I can mostly tell if it looks like it's going to explode so I put it in the sink. Then I either break the surface tension with a tea spoon or drop a small amount of sugar in it. However I don't want it to do that as I've just lost a load off coffee. I've had this happen in 2 different microwaves, so it's most likely down to the very particular set of criteria I create. I will endeavour to record this happening, but don't expect proof any time soon.
Today I learned! Thanks, Fran.
The user's manual of my microwave has another fix:
When heating liquids, always put a spoon inside and try not using an extremely long and narrow vessel.
And yes, a spoon in the microwave won't hurt either the microwave or the spoon, as long as there's water inside.
10:23 I almost remember that aftermarket 3rd party rotators were available for Microwaves that didn't have them.
I heat water for tea in a microwave in a Pyrex measuring cup.
Sometimes when I drop in a teabag it boils around the teabag.
They definitely were a thing. I have an old wind-up one.
This is something to watch out for. Water boiled in a microwave can indeed be well over 100C/212F. This is why a tea bag or coffee granules cause the water to foam up.
I recently took apart a microwave and found that the part that rotates the plate can be used as a shocking device if you hold the 2 contacts and turn part that connects to the plate
Even nowadays, with the the turntable, when I heat a glass of water for my tea it happens when I insert the teabag: then it boils abruptly.
My turntable thing broke a year or so ago. When i'm carefully trying to convert my frozen lasagne into a hot one i have been moving the tray around manually. Sometimes regularly, sometimes less so. Had started to notice it seems to make no difference... Thanks Fran
Same problem here. For me makes no difference with food, but with food I have to rotate else food is charred in spots and raw in others.
i do have a 900watt bloody hot air grill combo big-ass microwave :-D yep. .
Put a teaspoon of non-dairy powdered creamer in a mug of hot water after you remove it from being heated to a point of more than necessary. It will foam and spill over quite violently.
Really enjoying these Fran's Chemistry/Physics episodes
Maybe I am weird but this is one of those things I knew about and tried to reproduce without luck. Like trying to get linseed oil soaked rags to spontaneously ignite.
I have experienced this with soy-oat milk, new mug, really clean, really smooth. And I put the handled milk frother in... As soon as i touched the milk, poof! It was a small explosion, I have not felt anything, no burns but damm scared me! And it was not even that hot and I heated it for a little time... crazy!
A nice story but not true!
lookup "Superheating of water (Mythbusters)" here on youtube.
they superheat water in a regular microwave with a rotating plate.
they even put the glass on the edge of the plate - not in the middle.
(they used 2 glasses one with regular water and one with distilled water in order to know when the water should have boiled)
That was about the best way I’ve ever heard anything explain thanks Fran
Time to replace that little rotisserie motor that has been dead for 3 years. During that time I discovered my microwave's hottest area. Also, noticed for even heating of water like substances placement does not make much of a difference, but for even heating of food items I have to turn microwave off and manually rotate plate/item several times or more depending on cooking time, else parts get charred. Now if you can just tell me how to prevent that little friggin motor from burning out every year? May try sealing rim of hole of that mandrel thingy with some material -any suggestions on material to seal?
Very interesting VID on microwave history. I was captivated throughout - you could try ending couple octaves lower though.
I do not have a microwave oven.
Hey Fran, I’d like to see you do a video on removing the magnets out of a microwave….That would be a lot of fun….Thanks for all of your great content….Take care…
Am I missing it, or have you commented on these balloons (.) we’re hearing so much about?
Our first microwave had a metal tray and a probe you were supposed to put into water to heat it up
Not everyone has a microwave oven.
The earliest induction ovens were made to melt metal.
I remember the cautionary tales about superheated water, but I did not know the full story. Thanks for the explanation and entertaining presentation
Thanks for the super explanation of superheating, Fran! Didn't know that was the real reason for those revolving platters in microwave ovens. Cheers!
Fran, This is a reach out.
I'm thinking you could pull this off.
Create a musical greeting card using some sort of speaker, Chip/ram..... and Lastly use Music Macro Language for Notation.
It would kick-A$$
I remember tales of Idi Amin in Uganda having a new microwave... It seated six..!
Oh, that's why that happened ha ha ha. I thought it was because the light exploded but I guess the light not working must have been a consequence of the water exploding. They should put warnings on microwaves. Maybe they do? I wouldn't know because instructions are the last thing I'd read when trying to microwave water lol. If it weren't for Fran nobody would know this because no one has ever read the instructions. I'll bet her microwave says the actual time. Mine says 12:00
Oh, I love your channel
Interesting story. Now... Give my best to Arne Magnusson! Because unforeseen consequences are everywhere.
Well, now I have another way of boring people around me. Thanks Fran. Seriously though, well told, even I understood why this was happening. Thanks Fran!
Cut a grape in half and microwave it to make plasma. Just don't put it on the bare surface of the microwave, it'll make a burn spot.
My current microwave has the spreader in the top and it is so much better than those stupid turntables.
I don't have a microwave.
Try grapes with seeds in a microwave;-)
My parent's had a microwave without the spinning twirly-ma-jigger and I remember being told to not put an egg in a microwave because it will explode. Well, I thought that was just nonsense 😄 ... soooo one day I put one in there for 30 seconds (nothing happened) and then another 30 seconds (again nothing), I did that again and I pulled the plate out of the microwave to further examine the egg. I noticed that it was sweating and I saw a tiny crack in the shell. I grabbed a toothpick and gently poked it into that crack ... **KA-BLAMMO!!!** , it eggsploded like a grenade 😄🤣 ... egg and shell all over me and the kitchen. I then proceeded to clean up the scene of the crime. The following day I was talking with my mom (in the kitchen) and suddenly she looked up and said "How in the world did eggshells get all the way up on the ceiling?". I tilted my head and said "Hmmm, that is rather odd isn't it?". I quickly changed the subject 😄🤣😄🤣
Ah ah ah, I tried a similar experience when I was a novice owner of a microwave.
I wanted to prepare a boiled egg, and I though to just put it on the microwave. I put it inside (I think it was in a water glass), and just started the oven, set for some minutes of cooking. After some minutes I heard a real explosion, the microwave door opened smashing glass and water on the floor, and the egg was really pulverized on the oven walls with pieces on the floor. 😱
It took me an incredible amount of time to clean up the egg from the inside of the microwave oven...😓
I learnt that YOU SHOULD NEVER PUT AN EGG IN A MICROWAVE.😁
Many old microwave ovens had what looked like an unpainted fan in the top interior that in reality was a deflector for the microwave beam, serving to sweep the beam throughout the interior of the enclosure. This had the unfortunate effect of requiring the microwaves to enter from the top, which reduced the useful interior volume and added the expense of a microwave waveguide.
The lazy susan was added to simplify the overall system, as it could be driven by the same motor used to drive the fan that cooled the microwave source and power supply. Plus, the lazy susan mechanism was less expensive than a waveguide, as the raw beam could be dumped in from the side, with little regard for beam shape or uniformity.
Today's multi-mode microwave ovens (that include, say, an air-fryer or convection capability) can't use the lazy susan, and instead use beam forming, sweeping and interior reflection to help ensure uniform cooking.
Very interesting! :)
our 1980s one (see other comment) has this, but it's behind a cover in the ceiling. The blades are spun by exhausted air from the cooling fan, but the turntable is driven by a motor.
Also, it's 60cm wide (the width of a standard large appliance in Europe), which is way wider than modern machines, I think this made room for the magnetron and spinning wave guidance system, though of course everything else inside there looks super clunky in comparison anyway
Our 70s Thermador had the "fan" deflector. It also had 3 power settings, but did not manage the power by changing the duty cycle of the magnetron as all modern microwaves do. Instead, it put the magnetron in series with a power resistor, which dropped the radiated energy of the tube.
🇬🇧 we have a built-in Neff combo microwave that I think has the rotary fan thing above the grill elements, as it also functions as a second “small” oven and grill, the lazy Susan thing is missing but it is still managing to evenly heat food, and we “thankfully” haven’t had that thermal runaway thing with overheated water
A funny story..... My father was USAF during WWII and Korea. He said that guys would put their waxed paper (common before lots of plastics) wrapped sandwiches in the fixed giant radar dishes and sometimes later enjoy a hot lunch. I guess the first Radar Ranges were courtesy of Uncle Sam :).
Also sometimes happens with my induction cook top when heating up water in a non-stick pan. There is no sound, but as soon as you pour out the water it *instantly* boils viciously! A very weird (and frightening) phenomenon.
This happens to me quite often in my turntable mw when I use a Pyrex measuring cup to heat water and miscalculate the amount of time to heat by just a little bit. if I'm adding anything to it. it will explosively boil over. I've just learned to add a tiny amount of whatever and it fizzes up less violently and then it's done and I can add the rest of whatever. (usually Cocoa or bouillon powder). if I just way over blow the time I will usually hear a pop and the pyrex plinking on the turntable and of course there's water everywhere.
I've worked in various Cafe kitchens in the UK, and none have had a turntable.
Generally industrial microwaves don't have a carousel, nor do powerful domestic microwaves.
We've got a 1000W Sharp domestic microwave, and it has no carousel.
@@johnnodge4327 Maybe power levels are the deciding factor?
Always heard those things called a turntable or carousel, not a rotisserie like the rotisserie chicken cookers at Costco. Anyway, the primary reason for the carousel was to make cooking more even. Uneven cooking was a major problem with microwaves up into the 80s and made microwave food a joke. And it stayed that way until the 80s when very smart engineers were able to do a better job tuning the wave guides and adding fuzzy logic to the controllers. But the carousel was a simple, low tech and cheap way of dealing with the issue while at the same time commanding a premium price at retail.
I'm not sure I buy this theory! You can still superheat water in a microwave with turn table, and the uneven heating resulting from not rotating is pretty marked! People don't want spots in their food still frozen. And I'm not sure I buy that it's that expensive to feed rotation through the shell!
We got our first microwave, a big woodgrain Kenmore, in '85. No turntable, but it did have a temp probe, so you could set it to cook to a set temperature. Worked perfectly with only a couple lightbulb changes until 2012.
Kenmore still seem to last forever, once its steel inside
You can still superheat water with a rotary microwave. I've accidentally done it several times over the years. Fortunately not energetic enough to shatter glass and spray scalding water all over me, but it certainly scared me when the container of water flash boiled when disturbed. All our microwaves have had turntables, every time it's happened the water had been boiled, left for a while then 'reheated'. I've even managed to get the container out of the microwave and then had it 'explode' when a spoon or ingredient was added.
I think the biggest risk factor is heating the water to boiling, letting it cool a bit, then heating it again. When you heat it the first time dissolved gases come out of solution first, creating bubbles that act as nucleation points for the subsequent boiling. But once it's boiling those dissolved gases get carried to the surface, so they can't form bubbles for the second heating.
Pits, cracks, and scratches help by trapping a bit of vapor when the bubble breaks loose, so the nucleation point is preserved, but if they're filled with liquid they don't act as nucleation points, you still need a gas-liquid boundary for that.
One of the few things I remember from chemistry lab: boiling distilled water in new glassware can do this. It is called "bumping". Scratch the bottom of the vessel with something metal so there is an edge for the the boil to "seed". You can use glass chips, too, but that's a very bad idea in the kitchen.
I have seen this phenomenon. I had a mug of water in the microwave too long. when I reached in to pick up the mug, the water in it suddenly exploded in a rapid and intense boiling that splashed some hot water on my hand. It was quite painful.