How does a freeze dryer work?

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Harvest Right Freeze-Dryer: affiliates.har...
What’s the difference between freeze drying and using a dehydrator?
Both the dehydrator and the freeze-dryer have the same goal, to remove moisture from food. Removing the water from food allows it to be preserved for a lot longer without it going off. This is because water helps facilitate the growth of things that contribute to foodborne illness, removing the water makes it harder for bacteria, mold, and other stuff to live and therefore the food stays fresher longer. Drying food as a form of preservation is pretty much as old as we are, but around 1930 the process of freeze-drying food was developed and although it also essentially just removes water, how it does it is completely different, which means the end result is completely different.
So today I want to show how these differ by making some cheese powder, which I think shows really well how these two different methods of removing water differ. Something not entirely new for this channel, a few months ago I made some instant mac and cheese and some Doritos using cheese powder I made in the dehydrator.
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