Thursday, October 3, 2013

Solar Powered Food

It's been a busy summer. I won't make any excuses or apologies for being gone from here for so long.
It's been a busy summer. (Did I say that already?)

A couple of months ago or more, I promised the readers of my newspaper column, The Gardener's Corner, more information and photos of the solar powered dehydrator that my husband built at a workshop last fall.

So here it is at last. The dehydrator is approximately 4 feet by 4 feet and contains four trays made of wood frames and a stainless steel mesh. Don't use aluminum or non-food grade plastic screens, since the food lays directly on the mesh/screen. The wood on the lid and screens is finished with food beeswax and natural linseed oil (not the stuff at the hardware store with lots of toxic things in it).

The lid has an aluminum metal plate painted black and is topped with clear, corrugated green house plastic. The metal is on the bottom of the lid and the plastic is on top, leaving air space between them. The black-painted metal allows the dehydrator to heat up, but does not expose the food to direct sunlight, preserving more of the nutrients and flavor. The screens sit on a frame of 2x4s. On the bottom of that frame is corrugated metal roofing. While the openings at each end of the corrugated plastic on top are blocked to prevent heat from escaping, the ends of the metal bottom are left open to promote air flow and prevent moisture build-up.

My husband built the stand on his own and added hinges to the top of the lid and a handle for lifting the lid. We use a length of 2x2 to prop the lid open for when we load and unload the dehydrator. Here it is loaded with tomatoes and eggplants. The dehydrator is set at an angle to better capture the sun's rays. Wheels would make this much easier to move, but new ones were expensive and we haven't been to the salvage yard yet. Wheels off of a lawn mower would work well here.

Because the trays can be removed, cleanup is quite easy.

I was really eager to get started drying tomatoes in late July. I had planned to dehydrate many of them and had planted Black Plum Tomatoes specifically for drying. They have a lovely dark color and are small, pear- to oval-shaped. See how lovely they are?

 The Black Plums turned out to be too pulpy for dehydrating, but they are the best tomatoes for roasting that I have ever tasted. So, the larger Amish Paste Tomatoes were the main ones for the dryer.

It took several tries to get a good batch of dried tomatoes. The mostly sunny days that the National Weather Service forecast for my first batch turned out to bet mostly NOT sunny. You kind of need sun to make a solar dehydrator work. Most of those tomatoes got moldy. Another batch also got moldy, in spite of considerable sunshine. The dehydrator was next to and facing a large area covered with a couple of feet of chipped wood. We figured that the wood made the area too humid and that mold spores blew into the dehydrator from the wood. After moving the contraption, we had more success with the tomatoes. They are quite wet and take at least two very sunny days to fully dry. So we left them in for at least part of a third day, or finished drying them in our little electric dehydrator after the second day.

Be sure to turn the tomatoes at the end of the first day, or they will be plastered to the screens and difficult to remove when fully dry.

Eggplant slices were quite easy. They took less than two full days to become crunchy dry. I like them crunchy, my husband likes them still a bit leathery. Tomatoes are leathery when properly dried; if crunchy, they are too dry.
From left and clockwise on plate, dehydrated tomatoes, plums and eggplant. Pretty much any vegetable or fruit can be dried.

We had a tree full of Stanley plums this year. At first we thought they were so-so in flavor, then they got a bit riper and we started to like them. But we also decided to dry some. After drying our first batch, we decided to dry all of the rest of them. I've been buying expensive figs for snacking, and the plums are every bit as good as those.

You can dehydrate pretty much any food. Dehydrated food takes up much less storage space than wet stuff. Dried foods should be kept in air-tight containers. We use canning jars with lids. For longer storage and better preservation of color and nutrients, store dehydrated foods in the freezer. Since we did not fully dry down our plums, they are in jars in the freezer. The tomatoes and eggplant are on a shelf. It's best to protect from light.

To dehydrate tomatoes: Core and cut off bad spots then plunge into boiling water for one minute (or steam for 3 to 4 minutes, don't steam more than a single layer at a time). Cool slightly and slip off skins. Cut larger tomatoes into quarters or smaller pieces; halve small tomatoes. Lay on drying racks and turn halfway through the drying process.

To dry eggplants: Cut off stem and blossom ends and cut out bad spots. Slice about a quarter inch thick or slightly thicker. The long Asian eggplant we cut on a diagonal to get larger pieces. Because we like to eat them as crunchy snacks, I toss them with a wheat-free soy sauce before putting them in a shallow glass baking dish. If you are going to rehydrate for cooking, skip the soy sauce toss. Bake at 350 degrees F. for 15-20 minutes (depending on how deep they are in the dish). Cool and place on drying racks. Never layer anything more than a single layer deep on drying racks and try to avoid having things touching.

To dry plums: Wash. Cut off bad spots. Halve and remove stones. Lay on drying racks.

Almost anything can be dehydrated. Vegetables generally need blanching, while fruits need no heat treatment. However, it is recommended to dip some fruits (apples, pears) in lemon juice or ascorbic acid to prevent discoloration. If you don't care whether they brown, skip that. Numerous books and online sites will give you particulars about dehydrating various foods. Even meats can be dehydrated -- but I'm not going there.