|Home || Art | Books | Dance | Garden | Homestead | Music | Recumbents | Schedule | Violins || Contact|
Building and Using
Solar Food Dryer
How-to ~ Ideas
Ideally we would get the majority of our food directly, from plant to mouth, as other animals do, with a minimum of fuss. It makes life a lot easier and is great when it happens -- certainly a goal worth pursuing. But most of us live lives and in places that require some food preservation for times when direct harvest isn’t possible. The solar food dryer makes this a lot easier for the busy homestead. And the results are good, too!
As a homesteader with more interests than
time, simple root cellaring tops my list for out-of-season eating and food
roots and many fruit do well this way -- easy in and out.
MATERIALS needed to build this dryer are not expensive, and many can be
salvaged. It is a design that is easily modified to suit you, your materials and
your budget. The accompanying photos and drawings should give you a good idea of
where you are headed.
<< underside of dryer
WOOD FRAME is a simple 2x4 grid with 1x3’s across the top and bottom. The top
1x3 is set down so there is a 3/4" air space across the top; the bottom 1x3
is set up so there is a 3/4" air space at the bottom. The bottom of the
windows sit on the bottom cross piece and the top of the windows sit on 1x4
pieces spaced appropriately. We also screwed scrap pieces on the bottom to keep
the windows from slipping down. The windows need to spaced high enough to leave
room for your food trays and shade frames. The air pattern is in at the bottom,
flowing under and up through the food trays, exiting at the top of the dryer
under the shade panels or glazing. Your dryer design needs to allow and
encourage this air flow.
<< looking from the bottom edge
CORRUGATED METAL ROOFING is the bottom layer, laying across the 2x4 frame. Fairly deep corrugations are best to allow good air circulation under the food trays, which rest on the tops of the corrugations. We could only get shallow corrugated roofing when we built our unit so we put rounded 1x1 sticks vertically under the food trays to get a bit more air space.
<< trays of apple pieces ready to dry
FOOD TRAYS are the next layer in the dryer sandwich. They have to be sturdy
enough to hold the wet food, non-toxic and able to withstand the heat of the
dryer. It’s hard to find a good, inexpensive solution here. Regular window
screening, whether metal or fiberglass, is not food safe. One option is to use
galvanized hardware cloth covered with lightweight cotton to keep the food off
the galvanized wire. Some foods are sticky and so won’t be easy to manage on
cloth, plus air won’t flow as easily through it. But it will work. Cloth
tightly stretched across a wooden frame is an option, too, though it tends to
sag under the weight of the food. A under-frame of small dimension wood would
help alleviate that problem.
<< shade sitting on open window ready to be place on tray of strawberries
SHADE over the screen is important to keep the sun off the food, plus it can
help absorb/transfer heat down to the drying food. A simple thin, black cloth
can be draped over the screens but it tends to stick to some foods and is a
hassle. Initially we stapled black material to wooden frames which sat on the
food trays. This kept the material off the food but the material faded fast and
had to be replaced too often. Meantime, Larisa had mentioned they had tried and
were happy with black painted metal attached to the underside of their windows
(they were using corrugated fiberglass glazing). It was easy to manage and
worked well. And they discovered that it worked best to paint the underside as
well as the top side of the metal black.
WINDOWS are the final piece of the unit, sitting on top of all, enticing the sun and heat into the dryer and discouraging rain and debris from entering. I prefer wood framed, glass glazed windows. But you can use whatever glazing suits you. For ease of use and dismantling, each set of two windows is hinged with loose pin hinges along their adjacent sides (slightly loose fitting nails work great for replacement pins). The windows sit slightly above the shade frames on supports that are part of the wooden frame, with bottom stops to keep from slipping down off the unit.
USING THE DRYER is simple, but it is not
mindless. The whole unit is propped at an slight angle toward the sun, using
shims to raise the back up. How much of an angle depends on how much your drying
food wants to roll to the bottom of the screens. And you need sunshine. Several
sunny days in a row. A few clouds will be OK, but if it gets very cloudy or
overcast, there won’t be enough sun heat for drying. How this affects your
food depends on what you are drying and what stage of drying it is in. A good
sunny day for the initial drying is important so I don’t bother filling the
dryer unless it looks like the weather will cooperate.
Once the food is more dry than not, I put it in a covered bowl or pot at night to equalize since the individual pieces dry at different rates. Then back on the screens and into the dryer the next day. If the weather clouds up so you can’t return the food to the dryer, spread it out on the trays anyway. Until the food is quite dry, there is the possibility of mold if left in the covered container. When it IS dry, however, I leave it in a covered container for several days, stirring once in awhile, before storing in lidded jars. All those canning jars that you are no longer using work just fine for dried foods, and you don’t need nearly as many as when you were canning the harvest.
THE FOOD itself is, of course, the heart and soul of the solar food dryer. There are many books on how to prepare food for drying, and I recommend reading all you can find. Most advocate much more aggressive preparation and warnings than I subscribe to, but you have to go where your beliefs take you. My favorite is Larisa Walk’s booklet "A Pantry Full of Sunshine - Energy Efficient Food Preservation Methods" ($11.75 ppd from Larisa Walk, 30319 Wiscoy Ridge Rd, Winona WI 44987; or online at www.geopathfinder.com) since I share her practical, cooperative approach to food. My food drying and the foods I dry are pretty basic but you can be as adventurous as you like with a wide variety of fruits and vegetables.
APPLES are one of the main inhabitants of my solar food dryer, though because of their seasonal timing, later batches often are dried indoors over the wood stove instead of in the outdoor solar dryer. We eat fruit sauce most mornings for breakfast (with raw oatmeal and other amendments), and apples are our main fruit, so I cut up and dry a lot of apples. Simply peeled, cored, cut into pieces (maybe half inch or so) and spread on the trays, this is much easier than canning. And you can eat the dried fruit as is, in addition to cooking it into a sauce. Apples are naturally a drier fruit than most so are easy to dry and will tolerate less than ideal weather much better.
STRAWBERRIES are fussier, but if we’re having a bumper crop, I do several batches of these as well. They are great additions to the dried apple sauce in late winter, or for camping. When backpacking, we simply add water to dried apples and strawberries at night, having "instant" breakfast sauce ready in the morning. Strawberries are incredibly sticky as they dry, so I prefer the small or medium sized berries that I can simply slice in half, laying them skin side down on the tray. Large berries get sliced in thirds or quarters so some of the pieces have to go wet side down on the tray. Later, they are peeled off and turned over. Once they skin over they are easier to handle. You want to have good sun for strawberry drying as they are quite a wet fruit.
SNAP BEANS are easy and one of the two main vegetables that I dry. I cut or snap them into relatively same size pieces (maybe half to three quarters inch), steam blanch them 10 minutes (they don’t taste as good if not blanched first), then spread on trays. They dry fairly easily. Reconstituted dry snap beans don’t taste like fresh or canned beans, so you may want to do a small amount before drying your entire harvest, depending on how picky you choose to be. They take a surprisingly long time to reconstitute/cook but give flavor and texture to winter soups and vegetable dishes.
CARROTS are easy to root cellar, but they don’t last until the new crop is ready, so if I have a good harvest, I dry some for that lean time. I found dried carrot pieces to take too long to reconstitute/cook for most of what I used them for, so I switched to shredding them. Either way, they are pretty easy to dry. Simply wash, shred on a grater, spread on trays and dry. I like to add a handful of dried carrots when cooking rice.
is probably my favorite dried food success -- green, or sweet, corn -- not
mature dry corn for grinding. I’ve never dried enough to last through the
winter, though I keep trying. It reconstitutes closer to its fresh taste than
any other food I’ve tried. Of course, to get that great flavor, the initial
harvest has to be of good, ripe, fresh, NOT overipe, green corn. If the corn is
chewy and past peak when you harvest it, don’t bother to dry it -- it won’t
get any better.
ARE MANY other vegetables and fruits you can dry in your dryer, of course. Once
you start using your dryer, you’ll discover what works or doesn’t work for
you. A handful of extra peppers are easy to cut up and dry, or leftover garlic.
Herbs can be dried in the dryer, but I find they do better simply hung in a back
room of the house. The dryer can be too hot for sensitive herbs. Homemade
camping food is easy to do-your-own, and much cheaper and better than
store-bought if you do even a moderately good job.
Copyright © 2006 by Susan Robishaw
We always appreciate links to our site www.ManyTracks.com from appropriate sites, and we thank you for recommending us!