Dehydrated vs. Freeze Dried Foods

May 29, 2014, by Ken Jorgustin


Curious to know the basic difference between dehydrated food and freeze dried food, or how they relate to your survival food storage?

Let’s start with a basic understanding of what each process.



Dehydration is simply the process of removing water from a substance, in this case – food.

In addition to professionally processed dehydrated foods, this is something that you can do right in your own home in a low-temperature oven or a purpose-built food dehydrator.

Moisture is removed from the food by slowly heating it at temperatures which may range from 115-F to 155-F depending on the food itself. Typically a fan circulates the air within the dehydrator to evenly distribute the heat.

Typical food moisture levels may be reduced to a range between 10 to 20 percent – depending.

Home dehydrated foods (which typically may not be as dry as professionally dehydrated foods) have a ‘typical’ shelf life ranging from six months to a year, however it is fairly easy to obtain much longer shelf life for many dehydrated foods by way of cool storage coupled with a vacuum sealed containment.

Dehydrating at home is a great way to store extra food from your garden, or vegetables and fruits you have purchased at the market at a great ‘sale’ price.

Advantages of Dehydrated Food

No waste
Low moisture
Do it yourself
Long shelf life
Not easily spoiled




Freeze drying is a dehydration process as well – with some differences which enable the food to become MUCH drier than dehydrated food.

The freeze-dry process is a professional process which is very expensive to reproduce at home.

The foods are cooked, processed and then they are frozen. During the freezing process, the surrounding air pressure is reduced (vacuum chamber) to allow the frozen water in the food to change from a ‘solid phase to a gas phase’ to remove even more moisture.

Freeze drying removes more water than dehydrating (down to just a few percent), so it lengthens a food’s shelf life. Many vendors of freeze dried foods claim shelf life as long as 25 years.

Freeze-dried foods can be amazingly tasty and good – due to the unique process which retains even more flavor and nutrients.

Advantages of Free-dried Food

Very long shelf life
Very lightweight
Very low moisture
Reconstitutes quickly
Best way to dry meat items
Generally tastes better than dehydrated
Retains original shape, texture, color after reconstitution


Both dehydrated and freeze-dried foods have a place in one’s diversified food storage. Freeze-dried is more expensive although very light weight with a long shelf life. Dehydrated food can be processed at home, albeit with a shorter shelf life – but that’s okay because you’re growing a garden every year – right??