Wednesday, July 1, 2015

Solar food dehydrating

Preserving food is essential for those who want to maximize home grown food year round. So far from our garden, we've canned a lot of stuff, put up a lot in the freezer, have dehydrated veggies in our Excalibur, and I even tried fermenting and made a batch of kraut.

To really reduce energy use in food preservation, solar is the way to go. There are a lot of designs to choose from, but I built our dehydrator based on the design developed by the homesteaders at

These homesteaders (Larissa and Bob) have been at it a long time, and the site has some other good stuff also.

I have enough materials to build a second one like that shown in the photos, but if we decide we need even more capacity, my plan would be to build the Appalachian State University design.

Until we decide to ( or have to!)  really cut back on power use, we will still freeze and can plenty of food, but right now we are experimenting with dehydrating various things, with the general intent to minimize energy, maximize retained nutrition, and of course, process in ways that leaves the food with good taste and texture.

You can use either glass or plastic for the transparent trapping layer, I used double wall polycarbonate. The glass or plastic needs to be suitable for the temps, as well as possible hail.

These are the 24" square removable trays the food sets on. I used stainless steel screen, and cedar framing. The black painted aluminum absorbs heat, and reradiates it to the food, while the heated air is channeled by the corrugated metal to send the evaporating water up and away. Larissa and Bob's website goes in to more detail.

Larissa and Bob have built theirs as a permanent outdoor appliance, but I used carriage bolts and made my legs and bracing removable, for storage indoors. Right now, I'm setting at a little over 15 degrees from horizontal. If this is too steep and food slides, I will just whack the back legs and redo the braces.

I used hi temp black stove spray paint on the heat capture aluminum sheeting. We'll let this outgas for a couple days, then give it a go.


  1. Hi Steve,

    Top work and thanks for the link. It will be interesting to see how it goes with your first use. Many years ago I ate sun dried cherries and they were amazing. Do you have a fruit in mind to put through the dehydrator?

    PS: I've been thinking about using an electric dehydrator too as I have so much extra electricity over summer.



  2. Chris, first through were some collard greens and kale. These did real well, and we will try some other veggies out of the garden as they are ready, but for fruit, it will be mostly apples from the old trees that came with the farm.

    Apples have done well in our electric dehydrator, so I think they will do ok in the solar. If we buy any local fruit, and decide to try dehydrating some, it will most likely be peaches. Our cherry trees are still young, so for several years, they will all be eaten fresh. If our grape vines ever kick in to gear, we'll also try making our own raisins.

    PS- I planted some paw paws this summer, but they take a long time to grow, and this is at thier northern limit, so don't know when I might see them.