I got some requests to write this diary from responses to a post about how wise we'd all be to grow as much food as we can and preserve it. I mentioned building a solar dryer last spring, and how it tripled the amount of food I was able to preserve (and my family to eat) from my beloved garden that grows the great weeds. If there is interest, I could do more diaries on such things, since it's really not that hard to grow food, preserve it, and make fine dishes with what you've provided for yourself.
I was searching through 'net-land last winter when I came across a site with plans for a home-made solar dryer. It was big-harvest large, but I quickly understood that I could make one myself with what we have here on my place. Basic components are a window, a box, a screen, a rack, and a piece of tin roofing.
First I dug around under the shed and got an old window salvaged years ago that still had all its glass. The old white paint was flaky and probably lead-based, so I scraped it good and repainted it with a flat black acrylic (the tough kind for outdoor use). The window in its frame is deeper on one side, so I designated the deep side 'inside' and attached a lightweight cotton black cloth (one of those loose-weave Indian cottons) to the frame on that side with tacks. This is for shade on whatever's drying, as direct sun through the glass will discolor things rather badly. Food can be dried without it, but it won't be very pretty!
Then I made the box. Used 1x6 boards obtained from a neighbor with a sawmill, he considers it scrap and gives it to us for free. It's heart pine (full of resin) that's never been treated. You do NOT want to make your food dryer with arsenic or creosote treated lumber, though salt treated is probably okay if you can't get raw. The box is for the window, it will not have a bottom. I just cut the pieces and screwed them together with the drill-driver. Attach the window at the top with a couple of heavy duty hinges (you'll be opening and closing a lot), and I put a hook-and-eye latch at the bottom for when I want a tight closure.
There are food-safe plastic screens you can buy for the bottom, but since the screen is mostly to keep flies out I just used some window screen and attached it with staples. It doesn't have to be pretty, but you do want to make sure it thoroughly covers the box (I stapled to the outside sides to make sure), and you'll want to fold it over a lath strip so there's no raw edges - you don't want to poke yourself with stray screen wires all the time.
I found a refrigerator rack from some 'fridge we'd taken to the dump years ago (compulsive saver of things that "might come in handy someday" here) out in the shed, still nice with its white enamel coating after a little cleaning. It happened to fit inside the box perfectly! So I put in a few little screws by hand two inches above the bottom on which the rack can rest. The depth dimensions are 1 inch between the glass and the cotton shade, 4 inches from the shade to the rack, and 2 inches from the rack to the screen. The 4 inch depth allows for initially bulky stuff like collards and kale and such to fit nicely without being pressed.
Now you're going to want to add an inch or two to the bottom sides. I used 1x2 strips, just screw them to the side boards on top of the screen. Leave the top and bottom boards as they are. Attach a piece of metal (I used a piece left over from one of the sheds, cut it carefully as that stuff will gash if it gets half a chance) to the strips on both sides. I put the dryer on a table on the front porch (south side) where it gets lots of sun, but you can put it on legs, on sawhorses or even on the ground. So long as the sun is shining, the box will get hot.
Prop up the top side a few inches (I use a brick) so that air can flow from the open bottom, through the chamber at the back where the metal is, and out the top. This is necessary convection that carries moisture away from what's drying in the box, and keeps your box from being an oven instead of a dryer. If it's really hot I prop the window open a bit - you'll need to experiment a little with various foods and conditions to optimize drying time and temperature. I play it by ear, but you could get fancy and use a thermometer or something, I guess. ;-)
Most all of the food you will dry from your garden or farmer's market (buy in bulk when it's cheap or slightly overripe!) is primarily water. Drying means removing the water content as much as possible, and that shrinks things considerably. Different fruits and vegetables should be dried to different levels of dryness so let me recommend a wonderfully useful book that has all the details as well as great recipes:
Food Drying with an Attitude by Mary T. Bell. She's writing for those who are using plug-in kitchen counter dryers - which are indeed handy during rainy days but cost a lot - but you'll know how dry things should be and how to use the results as food. When we get into our rainy period, usually right about the time the apples and pears are coming in by the bushel, I've been known to use the oven on its lowest setting. Bell talks about how to do this as well.
Drying the dark green leafies (kale, collards) has been my biggest discovery to date, as most of it went to waste because I always grow more than my family wants to eat on a daily basis. They're tremendously good for you and high in vitamin K as well as C, A and iron plus minerals, but none of us can stand canned greens. You can freeze them okay, but our electricity isn't the most reliable in the winter and that all takes up a lot of room anyway. I found that I could crumble the dried greens into flakes, which can be tossed onto or into just about anything - salads, pasta, soups, snacks, baked into bread, etc., etc. AND you don't get burned out on the taste of boiled greens!
Tomatoes were a surprise too. I sliced and dried a total of 16 pounds of heirlooms, as dry as they'd get. Then I put them into a ziplock freezer bag (all fit into one quart bag) for a couple of days so they got very brittle. Then I put 'em in the blender and turned them into powder, all of which fit into a pint jar which I still keep in the freezer. You can sprinkle that on stuff too (it's especially great on pasta), or use it to make soup stock or tomato sauce, a few teaspoons at a time. It rehydrates nicely! I figure I'll be out before this season's tomatoes come in, so I'll hope to dry much more this year. Cherry tomatoes I cut in half and dried not so hard, keep them in a bag in a fridge drawer, they rehydrate nicely too and taste far, far better than winter tomatoes from the store. I dried squash, eggplant (and powdered it for baba ganoush mix), snow peas, pumpkin, bananas, pears, apples (that didn't even last until Thanksgiving, family loved 'em as snacks), cranberries, blueberries, leeks, onions, garlic, herbs, oranges, celery, carrots, peas, beans... just about everything we had in excess, plus what was cheap at the farmer's market. Even made fruit roll-ups from apples, pears and my ample concord grapes, they got eaten fast.
Some things should be blanched or parboiled before drying, and I went ahead and quick-cooked fresh peas and beans before drying. That way they take only a fraction of the time to rehydrate and get to the table as beans dried raw. Corn can be done that way too, though if you grind your own meal like I do, just let it dry in the field. Dried food doesn't have to be processed further. No ball jars or caps to boil, no water bath or pressure cooking. Since food comes in mostly during the summer, the temperature of your house with stay cool. You can put it in ziplocks or saved jars or whatever. Just wash and dry the containers good. If it's not dry-dry, it should be kept in the fridge (or freezer). But dried food is so reduced in bulk that you can store massive amounts of it in not much room.
I enjoy my solar dryer so much I'm making another one. I could put them on sawhorses down in the garden so stuff can be loaded in right there, but I like to clean everything well and many things should be peeled or sliced first. So I put it on the porch right outside the kitchen and it's very convenient. There's a great feeling you can get from growing your own food, and being able to preserve it for the coming winter is also a good feeling. Some things just have to be canned, my grandchildren would just DIE if they couldn't get granny's pickles on demand - heck, I keep a gallon jar of refrigerator pickles going all summer, they go faster than I can refresh them. Some things can be kept nicely all winter in hay in a root cellar (pumpkins, winter squashes, potatoes, sweet potatoes, onions, leeks, turnips, celeriac, parsnips, etc.). Some crops are best to grow fall, winter and spring for fresh eats (lettuce, spinach, radishes, kale, peas. As you get used to gardening and preserving, you'll get used to what's what.
Powdered dry vegetables with strong taste (such as tomatoes) also make good gourmet table salts. I make my own garlic, onion and herb blend too. I combined a bunch of powdered stuff to make a bullion mix, which I use as soup stock or just as a cup of broth during the day (1 tsp. per cup, it's very good). Dried herbs - we grow five kinds of mint, 3 kinds of basil, sage and others - make fine hot teas in the winter too. I have a large hedgerow of wild roses, harvest the hips in October and freeze. Sweeten with raw local honey and you'll be amazed at how resistant to the usual coughs and colds you'll be! With recipes like cold melon soup, rhubarb popcorn, dragon crackers, rawmelette, moussaka, half-dried tomato spread, stuffed vegetable loaf, bloody mary jerky, etc., the book linked above has plenty and explains using dried instead of fresh or canned ingredients in any of your favorites.
Anyway, that's the basics on my home-made solar food dryer. I think just about anyone could make one that works fine - the sun's hot, it'll dry some food! In this economy I don't think it would hurt any of us to spend some time and energy reconnecting with our food supply, and you may even find you enjoy it so much that the food, exercise and fresh air and real relaxation you get from gardening might be a welcome change from couch potato-ness or hectic running-around. There is some real money to be saved growing your own, and by preserving your own you'll be encouraged to do more of your own cooking. Not eating out can save a bundle too! Hope this helps those who are interested.
Have fun!!!