What’s the Best Solar Food Dryer?

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Appalachian Food Dryer. Image: Mother Earth News.

Dehydration is a great way to put up food. Second to freezing, it’s the best way to persevere nutrition without adding sugar or salt. And if you use the power of the sun, you won’t need to spend any money on electricity.

In a desert climate you can just put your food out on screened trays. But just a bit of humidity in the air makes this approach risky. Food can spoil before enough moisture is removed. That’s why you should build a solar food dryer.


Brace Direct Food Dryer. Image: FAO.

There are two basic designs for solar food dryers: direct and indirect. Direct dryers are just a box with a piece of glass on the top. Indirect dryers use a box to collect the heat of the sun and then, thanks to the fact that hot air rises, take that heat up into an enclosed box that contains the food you want to dry.

The Poistk Dryer

The Poisson Indirect Dryer. Image: Mother Earth News.

Which design works best? Dennis Scanlin, Coordinator of the Appropriate Technology Program and Professor of Technology at Appalachian State University in Boone, North Carolina has been studying solar food dryer technology for decades. ¬†According to Scanlin, indirect drying is the way to go. Scanlin tested three dryers, the Appalachian Solar Food Dryer (an indirect dryer that he invented) against a direct dryer developed by the Brace Research Institute and the Poisson indirect dryer. In an article in Permaculture Activist, “Evaluating Solar Food Dryers: Stocking Up with Solar Power,” Scanlin says,

The Appalachian indirect dryer produced higher temperatures than the other two dryers and also removed more moisture from the tomatoes drying inside each day. In one test, the Appalachian dryer removed 32 oz. (0.95 L) of water during ta day, while the Brace direct dryer removed only 20 oz/ (0.59 L), and the Poisson dryer only 15 oz. (0.44 L). The Appalachian dryer was able to remove as much as 3.73 lb. (1.69 kg) of water in a single sunny day from tomatoes drying inside.

Scanlin also notes that direct dryers degrade the quality of the food and possibly nutritional value due to direct UV exposure.


Our Appalachian Food Dryer, badly in need of a paint job.

We built a Appalachian Dryer several years ago and it works great. You do need to remember to bring in the food at night to prevent rehydration and spoilage (for some reason I often flake out and forget to bring in the food). For awhile I had an electric Excalibur Dehydrator on loan and it’s a lot more convenient. But, of course, it uses electricity and makes a lot of noise.

Since I built my Appalachian Dryer Scanlin has decided that it’s not necessary to use insulation. This makes the project even simpler. For just around $200 worth of materials you can easily make an Appalachian Dryer out of plywood nails and screws.

You can find plans for Scanlin’s dryer here.

Making Tofu From Scratch at the Institute of Domestic Technology


Around once a month I teach a bread class at the one of a kind Institute of Domestic Technology, founded by our friend Joseph Shuldiner. The IDT is not your usual cooking school and its offerings are difficult to define succinctly. If I had to take a stab at explaining what the IDT does it would be that it teaches things worth doing from scratch that most people haven’t attempted since the pre-Betty Crocker era: cheesemaking, home coffee roasting, bacon curing, bread baking, jam and exotic projects like making your own nocino and toothpaste.

One of the perks of teaching at the IDT is getting to sit in on some of the other classes. The coffee roasting class changed my life. Now, every morning, I look forward to fresh coffee I roasted myself in a Whirley-Pop Popcorn maker. This past weekend I sat in a new IDT class taught by author Andrea Nguyen on how to make tofu from scratch.

Continue reading…

From the Archives: Loquat Leather


Judging from the reaction to Mrs. Homegrown’s post yesterday it looks like some folks have a loquat obsession. Welcome home brothers and sisters.

At the risk of tooting my own loquat horn and repeating an old blog post, Mrs. H neglected to mention my controversial 2012 loquat leather experiment and recipe. You’ve still got to de-seed the damn things but at least there’s no need to skin them. Plus it makes use of booze.

I’ll admit it’s not a thrilling fruit leather but it’s not too bad.

Mrs. Homegrown chimes in:

My philosophy is simply that if one is going to go through the trouble of making fruit leather, preserves, pies etc., one should use outstanding fruit. The flavor tells in the end. After all, the starving times are not upon us. Even Erik can’t get super excited about this fruit leather–as I recall it tasted mostly of lemon and booze.

Then again, some people may have outstanding loquats–it sounds so from the comments on the last post. The ones we have access to just aren’t fantastic for preserving–too watery, too light. I just learned that there are over 800 cultivars of loquats, so there’s going to be lots of different loquat experiences.

Food Preservation Disasters


It’s ain’t 24/7 kittens and rainbows at the Root Simple compound. We do have our homesteading disasters. I was reminded of this after I emptied a box full of failed home preservation projects and contemplated a stinky trash can filled with a slurry of bad pickles and too-loose jams.

Of course you have to break a few eggs to make an omelet and, in the interest of learning from mistakes, I thought I’d review two lessons learned.

Not Using Tested Recipes
I vow to use tested recipes from trusted sources. Both for food safety reasons and culinary reasons, it’s a good idea to use trusted sources for home preservation projects. Some of the recipes I tried were from unfamiliar books and dubious websites. Some sources I’ve come to trust:

Between those two sources I’ve got just about all the recipes I need.


One Ring to rule them all
When you’re done processing jars and they’ve cooled down, remove the screw bands. Why?

  • So you can clean underneath the band to prevent spoilage and bugs.
  • The screw band can create a false seal.
  • Leaving the screw bands on can cause corrosion.

That’s advice from our own blog and yet I failed, for some reason, to remove the bands on many of the jars I emptied. I found all three of the above problems as a result.

Have you had any epic food preservation disasters?

Sauerkraut demo at the Hollywood Farmers Market

Photo: Library of Congress

Photo: Library of Congress

Fellow Master Food Preserver Shelley Marks and I will be doing a sauerkraut demo this Sunday February 2nd at the Hollywood Farmers Market. We’ll make the kraut at 10 am and 12 pm. Between the kraut demos we’ll be sitting in the Master Food Preserver and Master Gardener table to answer questions for the duration of the market. Please drop by and say hello! It’s freeeeeeeeee!