Just as packaged, dehydrated foods were the survival food of the 20th century, freeze dried foods are all the rage today. We get all the longevity, the light weight, the interesting recipes and we get better flavor and nutritional quality. We don’t get the compact form of dehydration and like dehydration, most dehydrated foods need rehydration which ups your water requirements, but it’s still great stuff for survival food.
Freeze drying is getting pretty high tech indeed. I think some guy called what’s-his-name invented it. Clarenece Birdseye. Anyways, remember how the crystallization of water in freezing tends to screw up the texture and nutritional content of food? Bird-man found a way that by rapidly freezing things really really cold–using stuff like liquid nitrogen–like colder than stuff normally gets on planet Earth, he managed to not only get around these problems but he found a way to extract tons of this frozen water out of the product when it heated back up to what we think of as normal freezing temperatures. With this technique we exceeded most previous preservation methods except the Pueblo dwellers who’s sprits still laugh at us and say “hope you liked the beans” which still happen to germinate. Unfortunately it’s a really high tech process involving highly specialized processing and equipment. We cannot freeze dry food at home.
Some argument exists as to the methods of freeze drying and whether some of them leave behind anything undesirable in our food. At this point there are many reputable vendors to choose from who pledge to sell us a quality product.