Dehydrating is one of my favorite methods of food preservation. It’s cheap, healthy, and you can dehydrate a lot of foods that you might not consider. For example, I love to dehydrate hummus, eggplant jerky and even entire meals.
But, while there are dozens of foods you can dehydrate, there are also some foods which simply don’t dehydrate well.
Here’s a list of foods you cannot dehydrate plus some hacks to make the foods better suited for dehydrating. If you want to learn more about dehydrating, read this Expert-Level Guide to Food Dehydrating.
Blueberries, raspberries, blackberries and many other berries have a thick skin around them. The skin does an incredible job of trapping water inside. If you try to dehydrate whole berries, the moisture won’t be able to escape from the skin.
Simply smash the berries a bit to break the skin. Then moisture will be able to escape and you can easily dehydrate them.
Peanut butter is approximately 50% fat by weight. Fat doesn’t dry out so, if you try to dehydrate peanut butter, the fats will start to oxidize and go rancid.
If you want to dry peanut butter, you’ll need to add a starch like maltodextrin to it. This will bind to the fats, dry them out, and turn the peanut butter into a powder.
You can also buy commercially produced peanut butter powder.
Like peanut butter, avocado is too fatty to dehydrate. In theory, you could use maltodextrin to turn the avocado fats into a powder. I don’t know anyone who has had success with this. Sorry – but it looks like you’ll have to freeze avocados if you want to store them long-term.
Sorry to break it to you but most home dehydrators are not able to dehydrate meat safely (safety being the main issue here).
Meat needs to reach a temperature of 160F in order to kill bacteria and other pathogens in it. Most dehydrators – especially vertical flow dehydrators – don’t provide a consistent temperature throughout. The bottom racks might reach 160F, but the top racks can be a much lower temperature. See our picks for best food dehydrators.
To make sure all pathogens in the meat are killed, you can either boil the meat (in a marinade for flavor) before dehydrating or bake the meat after dehydrating. You might consider salt curing instead.
Yes, you technically can dehydrate raw carrots. However, they turn into incredibly hard rocks. Try to snack on these carrot-rocks and you will experience some nasty indigestion. Even rehydrating dehydrated raw carrots doesn’t work very well. I’ve tried boiling them for over an hour and they still remain chewy and tough to digest.
*The same applies to many other vegetables which have hard fibers (celery, parsnip, broccoli, beets…).
First cook tough vegetables to soften their fibers. Drain and let cool before dehydrating. Then they will rehydrate quickly and are great in soups and stews. Read about dehydrating vegetables here.
Most fruit juices are 85%-90% water. (1) It would take a very long time to dehydrate all this water. Even if you did go through with the messy process, you’d only be left with a tiny amount of fruit powder. It’s simply not worth it.
Canning is much better for preserving juices. Read about canning here.
Some people say they have success using dehydrated eggs in baking. But, in general, dehydrating eggs is a terrible idea because the egg proteins harden. Rehydrating doesn’t work very well with eggs and they remain gummy and gross.
Buy freeze-dried eggs instead. The freeze-drying process is completely different than dehydrating and gives very good results with eggs. Read about freeze-drying here and freeze-drying vs dehydrating.
Olives are another example of foods too fatty to dehydrate.
You can dehydrate olives so long as they are blended with lots of other low-fat ingredients. For example, I blend olives with cooked veggies and tomatoes to make a pasta sauce. Because the olives are just a small percentage of the sauce and are dispersed throughout, the entire sauce can be dehydrated. I also make yummy dehydrator crackers with olives blended into the mix.
I’ve heard of people dehydrating cheeses like cheddar, American, and gouda. After dehydrating shredded cheese at the lowest setting, they then blend the dried globs into a powder.
While this technically does work, it doesn’t make sense to do. The high-fat content of yellow cheeses mean that the dried product will go rancid quickly. It also doesn’t rehydrate well.
White cheeses (like goat feta or cottage cheese) have much less fat than yellow cheeses. (2) This makes them a better candidate for dehydrating. You can cut feta into small cubes and dehydrate to make a salty snack. It still goes bad rather quickly though. You are probably better off just buying freeze-dried cheese powder.
Cooked Whole-Grain Rice
I often dehydrate cooked grains/carbs like pasta, buckwheat, and quinoa to take with me backpacking. My reason for doing this is to save fuel: it would take me 20+ minutes of cooking in the field to make quinoa. By contrast, I can rehydrate dehydrated quinoa in a matter of minutes.
Unfortunately, this same trick doesn’t work for whole-grain rice. It takes about 30 minutes of boiling to rehydrate dehydrated whole-grain rice, which is basically the same amount of time it would take to cook it raw.
Blend cooked whole-grain rice (or another grain of choice) with some cooked veggies and lots of seasonings. Spread the mushy mixture onto dehydrator trays to make your own crackers.
Nuts and Seeds
By themselves, nuts and seeds have too much fat to be dehydrated for long-term storage.
I’ve had very good success using nuts and seeds in dehydrated crackers, sauces, and spreads. For example, I blend sunflower seeds with tomato sauce and veggies then dehydrate the mixture. It lasts for about 4 weeks and rehydrates in minutes (making it great for my backpacking trips or whenever I just need a quick meal).
You cannot dehydrate butter. According to FDA standards, butter must contain at least 80% butterfat — and we know that fats don’t dehydrate and will go rancid quickly. Further, butter is made by whipping those fats with water. With the water dehydrated, the butter becomes “un-whipped” and you are basically left with an oily mess on the dehydrator.
I once made the mistake of trying to dehydrate grapes. The result was a brittle piece of grape skin with an unpleasantly-bitter seed inside. While grape seeds are edible and even healthy, they aren’t something you want to snack on.
You can dehydrate seedless grapes whole. Otherwise, you’ll need to cut the grapes in half and remove the seeds before dehydrating. It’s a major pain. You might as well make juice or wine from the grapes instead. 🙂