Second in a two-part series (the first one is here), let’s discuss when dehydrated and freeze-dried ingredients are most optimal in trail food. We have posted many articles over the years on this subject; see Dehydrating/Freeze-Drying 101 for the links.
While you can dehydrate or freeze-dry almost any ingredient, not every ingredient is suitable for long-term storage or for lowering food weight. Some do better freeze-dried, in others, dehydration is your best option. This also plays into how you buy ingredients, should you choose to go that route, versus DIY at home.
Freeze-drying is generally better than dehydrating for foods that are high in moisture, delicate in structure, or sensitive to heat, because freeze-drying preserves shape, color, nutrients, and flavor much more effectively.
Quick rule of thumb
Freeze-dry if the food is:
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High in moisture (squash)
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Soft or delicate (where the ingredient would reduce by 90% of size due to dehydration)
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High in protein or fat (meat, dairy)
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Part of a cooked meal (A great way to use leftovers after dinner, freeze-dry a portion or two)
Dehydrate if the food is:
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Naturally low-moisture (herbs, greens)
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Fibrous or tough
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Meant to be chewy (such as jerky)
Freeze-Drying Basics:
Whereas dehydrating has a low threshold to do (you can use your oven, air fryer, or even the sun, or a dedicated dehydrator – which are affordable), a freeze-dryer is an investment. You have to be willing to spend the money, then use it enough to get your investment back. If you plan on processing enough food, it can be worth it (especially meat, or if you have a large garden). The Number 10 cans of freeze-dried meat sell for $65 to 90 now, so that can add up quickly if you eat a lot of protein while hiking and camping.
Food is processed into equal sizes, laid out on trays, typically pre-frozen (depending on the ingredient), and then placed in the freeze-dryer.
Food is frozen to well below freezing, then a high-power vacuum pulls the ice out as vapor. What is left is the dry food. You must seal it up air-tight as soon as the process is done, as it will pull humidity out of the air. Storing it with an oxygen absorber and/or a desiccant packet is important, as is sealing the container with a chamber sealer to remove all air. The process can take an entire day to complete, especially if the machine does all the freezing for you – it might be longer.
The food will be nearly the same size as before you dried it, retaining its shape nicely. It will rehydrate easily, especially if the food is cut into smaller bite-sized portions, and look nearly the same as when fresh. It will snap cleanly when properly dry. It should not have moisture left in it. At all. Avoid grease and fat, as they can cause storage issues; they will often not dry correctly.
Both cooked and raw food can be freeze-dried. Meat and eggs are stored well when properly freeze-dried. Avoid high-fat/greasy food. It will make a very nasty mess in your freezer (yes, I learned that lesson making breakfast sausage).
Freeze-dried food is lighter because it contains no moisture. But will take up more space in meals, for example, in your bear canister. And you must be more gentle packing it, as you can crush it.
With freeze-drying, you can dry both ingredients or full meals. It is up to you!
Rehydration is normally a 1:1 ratio of food to water. This ratio may change depending on whether the meat is soaked (it can take less) or sauces are used (they may take more). If meals, be sure to weigh each serving before freeze-drying it. Know how much it weighs, and once it’s dried, you can weigh it again. Then you have a better idea of how much water will be needed.
Many items can be rehydrated with cool water. Many freeze-dried ingredients can be eaten in the dry state (though drink water with it!)
Meals and ingredients will rehydrate in 10 minutes in boiled water, but if you are using both dried and freeze-dried items together, go for 15 minutes. As always, if you are at altitude or in cold temperatures, give your meals 15 minutes to warm up in a cozy place.
Freeze-Drying Tutorials:
- First Look Review Harvest Right
- Freeze-drying versus Dehydrating Pasta
- Freeze-drying versus Dehydrating Peas and Corn
- Freeze-drying Yogurt
- Freeze-drying banana bread (and pumpkin pie)
- Freeze-drying Salsa (with recipe using it)
- Freeze-drying cheese and store it.
- Freeze-drying rhubarb and celery
- Sealing Your Meals Like The Commercial Companies Do It
- Freeze-drying onions (sweet and red/purple)
- The Sweet Sides Freeze-Drying Cheesecake, Sweet Breads and Cake (link to our homesteading site)
- Freeze-drying the holidays.
- Freeze-drying Purple Onions.
- Freeze-drying and Using Refried Beans.
- Freeze-drying Eggs
- Primer On Cold Soaking Freeze-Dried Meats
- Freeze-drying Carrots As A Snack
When Freeze-Drying Is The Better Choice
Ingredients That Are Best Used Freeze-Dried:
Peas – Green peas shine being FD, and taste fresh. Use frozen blanched green peas for the best results.
Corn – Corn goes very hard when dehydrated. FD, it is like fresh. Use blanched frozen corn.
Green Beans – FD green beans rehydrate without being leathery. Use frozen green beans, as they are blanched.
Zucchini and Summer Squash – with the amount of water content, this freeze-dries beast.
Bell Peppers and other Peppers – Cut into slices or dice. They retain their shape with freeze-drying. When dehydrated, they go flat and become leathery.
Berries – Sliced strawberries, whole raspberries and blackberries, and similar. They are crunchy and light. Freeze fresh berries for best results.
Peaches – Freeze-dried stay the same size and are crunchy. Use as ripe as possible for the best taste.
Mango – Thinly slice or dice, use fully ripe.
Pineapple – Fresh or canned, freeze-dries well. Use as small a cut as possible.
Candy – This is the first item most people make in their new freeze-dryer.
Meat – You can freeze-dry meat you cook at home, or even canned meat like chicken. Dehydrated meat becomes hard and can go rancid. FD is far better.
Shrimp – Freeze-dry “salad” shrimp (the smallest). It is sold cooked in the fish department. I do not suggest using canned tiny shrimp, which is extremely salty. Stores far better than dehydrated. Dehydrated shellfish can go bad quickly.
Fish – Freeze-dry it cooked. Stores far better than dehydrated. Dehydrated fish goes bad quickly.
Sweet Breads – Thinly slice pumpkin, banana, and similar breads and fry them for a crunchy snack.
Cheesecake – Thinly sliced and FD for a crunchy snack.
Pies – Many pies can be FD, do thin slices, and eat as a crunchy snack.
Eggs – See this tutorial on doing raw eggs. For cooked eggs, scramble and then freeze-dry them. Eggs should not be dehydrated.
Yogurt – A tasty treat eaten dry (in drops) or in powder form, then you have instant yogurt to make up. Overall, yogurt should not be dehydrated.
Cheese – Almost any cheese that can be shredded freeze-dry well. It can also be cubed into small dice. Cheese should not be dehydrated in general.
Tofu – Thinly slice or dice, and freeze-dry, for use in soups. Or to stir-fry later on. It retains its texture, whereas dehydrating turns it leathery.
~Sarah