For our longer term food options, in addition to canned foods, we store dehydrated and freeze-dried foods in #10 cans. Both methods remove 98% of the food’s original moisture, increasing their shelf life by years (and in most cases, decades), making them excellent choices for long term storage.
So what is the different between dehydrated and freeze dried? Process, shelf life, taste, and price.
Dehydrated Foods are foods that have been picked at their ripeness and then dehydrated, where 98% of their moisture is removed. During the dehydration process, heat is used to remove moisture from foods. This is done through either air-drying, sun-drying or kiln-drying. Most home dehydrating machines use hot air.
Freeze Dried Foods are first flash-frozen under extremely cold temperatures, then dehydrated using a vacuum process to suck out remaining moisture. Freeze drying removes the water, but not the flavor, so freeze dried foods retain much all their fresh food taste, vitamins and nutritional content.
Freeze dried foods rehydrate faster, while dehydrated foods take more soaking and/or simmering time. In our experience, not all dehydrated foods rehydrate well.
Which option will last longer?
Freeze dried foods have a shelf life twice as long as dehydrated foods, most are good for 20+ years, making them the better choice for really long term storage. While some dehydrated foods will last nearly as long, the average life-span for properly store dehydrated foods is 5-10 years.
Utah State University’s Cooperation Extension says this about shelf lives:
Properly processed canned, dried, and frozen (never thawed) foods do not become unsafe when stored longer than the recommended time, but palatability and nutrient quality are diminished.
Both freeze dried and dehydrated are stored the same way. The cooler the storage conditions the longer they will last. They need to stay dry too to avoid rust on the cans.
Which one tastes better?
If you compare dehydrated and freeze dried options straight across, no doubt freeze dried wins every time. Freeze dried foods retain their texture and flavor better than their dehydrated counterparts.
In addition, because less heat is used during the freeze drying process, freeze dried foods also retain more of their nutritional value. With that said, freeze dried entrees are higher in sodium and more expensive. The separate ingredients, whether freeze dried or dehydrated, are just ingredients with no salt added.
If you are wanting to store meat long term, we highly recommend either your own home canned meat or freeze dried meat. With the exception of TVP and jerkey, there are not a lot of dehydrated meat options.
What about the cost comparisons?
What dehydrated Food lacks in flavor (versus freeze dried, dehydrated tastes pretty good too!) it makes up ten fold in costs. Especially if you dehydrate food at home. Due to the process required to make them, freeze dried foods are considerably more expensive than dehydrated.
Because of the costs, we store mostly dehydrated basics like wheat, rice, beans, oats, milk, etc. We keep freeze dried fruits and vegetables on store to supplement our meals.
Is space an issue for you?
Dehydrated Foods take up less space because they shrink during dehydration, whereas Freeze Dried Foods are frozen solid during the dehydration phase and therefore maintain their size.
Even though a #10 can of Freeze Dried Apples takes up the same amount of space as a #10 can of Dehydrated Apple Slices, you get more food in the dehydrated can.
Whichever you choose, remember this… both Dehydrated and Freeze Dried foods will require water to prepare, so make sure store plenty of water too.