The easiest way to dehydrate potatoes (and onions)

Dehydrated potatoes are one of my favorites among all of the food stuff for camping and hiking. They are cheap and light weight, they have very long storage life, and they can be used with almost any ingredients one happens to find from his backpack for nutritious and delicious camp site meals.

However, before a happy camper can take advantage of the wonderful properties of dehydrated potatoes, the potatoes must first be hydrated, and that can be somewhat tricky process.

For quite a many of enthusiastic beginners, potatoes have been the reason why they have only tried to dehydrate anything twice – the first and the last time. The end product of the dehydrating experiment has been an ugly mess, in which horribly discoloured strips of potatoes are glued together into a blackish-bluish-brownish lump of something disgusting. Therefore, there must be something wrong with the potatoes, or the dehydrator, or the whole idea of successfully dehydrating anything at home.


About 70-80 % of the dry content of potatoes is starch, a long chain polysacharide, which in addition to being the major source of energy in potatoes, has some very glue-like properties. In fact, starch is a fundamental ingredient of many water soluble glues, and as some of the older, or more eco-conscious, readers may know, a boiled potato alone can be used as substitute for paper glue. Another undesirable property of potatoes is their tendency to turn black or brown when in contact with oxygen, i.e. air. The discoloration is a product of several enzymatic reactions within, and among, the cells in the potato.

From dehydrator’s point of view, a good thing is that once we know what causes these problems, there are ways to fix them. First thing to do is to choose a potato variety with the lowest possible starch content. After cutting the potatoes into thin slices or strips, a quick cooking or steaming session kills the enzymes responsible of discoloration, and after careful sieving and separating the individual pieces of potatoes, they are ready for the actual dehydrating process. Bad thing about all this is the required ridiculous amount of work.

Fortunately, our friend, the big food industry, has exactly the same problems with potatoes, and they have tools to handle the problems. As you may have noticed, within the other small print on the bags of frozen groceries, especially potatoes, you can usually find words like “pre-steamed” or “pre-cooked”. The big, if not so surprising, secret is that the big food industry did not pre-steam the veggies to “let you spend quality time with the family by reducing your time in the kitchen”. They did it because, due to the properties of starch and the enzymes, they had to.

Whatever the reason for the pre-steaming has been, love towards the mankind or industrial necessity, frozen potato products are an excellent starting material for home dehydrating experiments. They are cheap, pre-cut, pre-steamed, pre-separated, and, against the standard industrial procedure, usually do not contain any additives.

My personal favourite for dehydrating is a frozen potato-onion mix. Not that I particularly wanted the onions, which are easy enough to dehydrate by themselves, but I was not able to find other so perfectly sized thin strips of potatoes without them, and for most of my potato dishes I also use onions.

The work flow for dehydration is as simple as it can get:

1. Spread the frozen potato strips onto the mesh of the dehydrator.

2. Dehydrate for 6-9 hours at 40-50 C

3. Store the potatoes in ziploc bags, protected from light and moisture.

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