Though my wife and I had been freezing, canning and root cellaring our garden's produce for years, one food storage method had escaped our attention until just recently: drying. This technique offers substantial savings in storage space. One bushel of fresh tomatoes, for example, equals 32 quarts of canned or just two quarts of dried, with minimum nutrient loss. And there's no lengthy stand-by-the-stove processing time. If you're a gardener with a penchant for do-it-yourself woodworking projects (or know someone who's handy), here's a dehydrator you can make, with the following step-by-step instructions and the accompanying illustrations. Or, use them as a starting point for designing your own version.
My dehydrator took me about 16 hours to build, and—using some salvaged materials—cost less than $100. It consists of four major components: the "box," a heating chamber, a vent system and five drying racks. The prototype shown here operates as an "open" recirculating system, in which the warmed air rises through the food chamber, extracting 80% to 95% of the moisture from the fruits or vegetables, and is then blown by a fan through the ductwork back over the heating element so the moisture evaporates. The "open" part of the system is the fresh air supply from the cutout in the door. When the dryer is in operation with the door completely shut and the heating element on, the upper three shelves are kept at a constant 130oF (ideal for most vegetables), while the lower shelves run a little warmer, making them best for drying fruits. To adjust the temperature (for drying herbs or certain vegetables), I simply open the door to varying degrees. Rotating the position of the trays helps to assure even drying and prevents overcooking the food on the lower trays.
Step 1. Milling and Cutouts. Lay out and cut the 5/8" plywood to fashion the dryer door, back, bottom, top and two side pieces (see the illustration for dimensions). Make cutouts on the back piece for the exhaust fan, vent pipe and electrical wire (if you are using a different fan system or model, modify your cuts as needed), and on the front for the air intake.
Step 2. Tray Slides. On the insides of both side pieces, mark guidelines for the top edge of the tray slides. From the ¾" 1x6 strips, cut 10 17 ¾"-long pieces for the slides. Glue and nail, using 1" finish nails, the slides in place, 5/8" in from the back edge of the sides (to allow room for the back piece to be set in place).
Step 3. Box Assembly. Attach the back to the sides with 1 ½"-long finish nails and glue, then attach the top and bottom. Turn the box over on its top and install the casters at the bottom corners, if desired. Set the box upright and prime it and the door with a good exterior-grade paint, followed by a glossy exterior paint when dry.
Step 4. Rack Construction. From the remaining ¾" strips of 1x6, cut 10 17 ¾" pieces and 10 16 ¼" pieces. Glue and nail or screw the pieces together to form five 17 ¾"-square trays. Cut the hardware cloth and nylon screen to size and staple it to the top of the frame.
Step 5. Heating Unit and Air Circulation System. Attach the heating assembly, the electrical box, porcelain light fixture and heating element. Once the electrical box is secured to the paint can lid and a 3/8" hole is drilled for the wire, you can wire the porcelain socket and install it to the electrical box. Be sure to ground the bare copper wire to the box.
Next, cut a 2"-wide slot, rim to rim, in the main body of the can for the heating vent, and cut a 4"-diameter hole in the bottom of the can for the moist air to enter back in from the main chamber. To secure the can to the 90o elbow, use metal snips to make equally spaced 2"-long cuts 1" apart on the crimped end of the elbow. Insert these "tabs" into the 4"-diameter hole at the back of the heater can and fold them back to secure the elbow to the heater body. (Note: If you have chosen to use vent hose instead of vent pipe, attach the hose to the fan and to the elbow with clamps.) Attach the 3" to 4" adapter coupling to the fan and the other elbow to the coupling. Cut the pipe to fit.
Once the air circulation system is in place, wire the fan box and install the two- prong plug. Install the heater can lid to the heater body, run the wire out the back through the hole provided, and install the three-prong plug. Finally, install the door hinges, a cabinet catch and a door handle, if desired.
Thomas H. Lavallee gardens, works with wood and writes in Salmon,
Idaho.
Copyright NGA
Reprinted with permission HouseNet, Inc.
Build-it-Yourself Food Dryer
by Thomas H. Lavallee