Freeze drying and dehydrating are often mistakenly used interchangeably when in fact they are two very different methods of preserving food and both with their own advantages and disadvantages.
Food deteriorates when exposed to heat, oxygen and water
Three factors that cause food to deteriorate are heat, oxygen and water. Freeze drying is currently the best method of protecting food from these elements, which makes it a superior method of preserving food compared to dehydrating.
While freeze drying may be a better method of preserving food over dehydrating, both have their advantages and disadvantages that make one better than the other depending on the circumstances and your individual needs.
Key differences between freeze drying and dehydrating food
Below you'll find a list that covers these key differences, such as a nutrition, taste, cost, convenience, so you can easily decide for yourself which option better suits your needs.
| Freeze Dried | Dehydrated | |
| Nutrition |
This form of preservation does not use any heat, so the loss of nutrition is minimal (mostly vitamins C, A and E); free of chemicals and preservatives |
This form of preservation uses heat, so it's inevitable nutrients and vitamins are compromised, but there is no change in fiber and iron content; free of chemicals and preservatives (some commercial dehydrators use sulphur dioxcide as a food preservative) |
| Taste | Retains flavour | Change to flavour due to oxidization |
| Texture | Hard and crisp (as is) and returns to original texture after reconstituting | Tough, stretchy, chewy (as is) and depending on the food;can be chewy or softer after reconstituting |
| Aroma | Unchanged | Depends on the food (i.e., herbs become more fragrant whereas other food loses its fragrance) |
| Appearance | Retains shape and colour | Shriveled, darkens and loses colour (some commercially dehydrated foods contain sulphur dioxcide so the food retains its colour and looks more palatable) |
| Convenience | Lighter in weight than dehydrated food, but takes up more space; reconstitutes quickly (10 minutes or less) using hot or cold water; most items can be eaten freeze-dried | Light-weight and compact; most food needs to be reconstituted before eating; reconstitutes fairly quickly (20 minutes or longer) using boiling water |
| Preparation | Food does not need to be treated in advance; food can be freeze dried whole, either raw or cooked | Some foods need to be blanched before dehydrating; cut to 1/4" in thickness; exercise caution when mixing foods as some foods will overpower others |
| At-home cost |
An at-home freeze dryer is expensive and ranges anywhere from $3,000 to $5,000+
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Price varies greatly, starts at around $60 for a small dehydrator, all the way up to $2,000 for a commercial-grade at-home dehydrator
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| Processing time | Process takes anywhere from 24-36 hours; can freeze dry from fresh, frozen or cooked | Varies depending on the equipment and food, process takes anywhere from 2-30 hours; can dehydrate from fresh or cooked (some foods need to be blanched before dehydrating) |
| Storage & Shelf Life | No refrigeration required; store food in air-tight containers or bags; up to 25 years | No refrigeration required; store food in air-tight containers or bags; depends on the food, but anywhere from 2-5 years |
| Foods | Fruits, vegetables, dairy, meats, full dishes | Fruits, vegetables, some meats |
Freeze drying or dehydrating - which is better?
Undoubtedly, there are advantages and disadvantages to both methods of preserving food, so determining which method better suits your needs depends greatly on how you intend to use the food, as well as how much time and money you want to invest. Freeze drying is the clear winner in terms of nutrition, taste, preparation and shelf life, but dehydrating is definitely more accessible with its low-cost equipment and quicker processing times.
Comment below if you have any experience freeze drying or dehydrating. We want to know which is your preferred method of preserving food.