There is a lot of food storage. It isn’t as simple as going to the grocery store and picking out items to eat, while you have different types of foods to chose from you also have preservation methods, namely dehydrated and freeze-dried.
Moisture is a catalyst for food spoiling, that is why the two methods are used to pull as much water out of the food as possible to so it can last for a long time stored. When it is ready to eat you put the water back into them (reconstitution) and eat it. While there are different processes and ways to perform them we are not going to get into that all here. Instead we want to take a look at the differences between the two and some of the similarities so you can make the best choice for your family and your situation.
Difference #1: Shelf Life
Because freeze-drying does a better job at getting moisture out of the foods they tend to have a longer shelf life. Most dehydrated foods when stored in the right conditions (cool temps) and in the right packaging (Freeze-Dried Foods in #10 Cans) will last 10-20 years while their freeze dried counterparts will typically last 20-30 years. Both foods will be edible after those periods they will just have a reduced nutrition level and flavor.
Then there is the complication that comes from ready to eat meals. The times mentioned above are for individual items like corn or strawberries, meals on the other hand are another beast altogether. Lasagnas, beef stroganoffs, and other just add water meals can be a little more complicated. Because they have a wide variety of ingredients it is important that the food scientist that engineers them picks the right ingredients that will yieild a long shelf life. Picking fatty or oily ingredients are a bad choice as they will go rancid fast.
Not all meals you see in the food storage industry are 100% freeze dried. Some are, others have a mix of freeze-dried and dehydrated items while some are exclusively dehydrated ingredients. Just because some of the ingredients may be dehydrated doesn’t mean that meal will only last 10-20 years. There are some dry goods that will last up to 30 years and beyond such as rice and pastas.
Difference #2 & #3: Taste & Texture
When comparing the two there are also differences in taste and texture. Whether you eat them dry or reconstituted there is a pretty good difference between the two. For me I favor freeze-dried in every case except bananas and carrots where I prefer them dehydrated. The freeze-drying is gentler on the cellular structure and as a result the food returns to a more similar state than the dehydrated versions.
Difference #4 & #5: Size & Weight
Freeze dried items tend to stay closer in size to their pre-preserved state. Dehydrating tends to shrink the product more. What does this mean? It means you can get more dehydrated food into a #10 can.
The freeze-dried counterpart tends to be very airy, or air filled. Some cans of product will be filled all the way to the top but only have 7 ounces of product inside! Dehydrated items on the other hand are more dense and tend to weigh a little more.
Difference #6: Cost
Cost is another difference between the two types of foods. Freeze-dried foods can cost almost twice as much as the dehydrated in some cases. The freeze-drying process if completed on multi-million dollar equipment and to run a batch can take as long as 24-36 hours. The cost and slower processing time makes this process more expensive. Dehydrating on the other hand can take as little as 6 hours for a batch and the equipment is nowhere as expensive for the manufacturer.