Humans have been using food dehydration as a method of food preservation for centuries. The process involves removing the moisture from the food, allowing the food to be stored longer without refrigeration. Common dehydrated foods include beef jerky, trail mix, dried herbs, sundried tomatoes and fruit rolls. While there are many countertop food dehydrators marketed to consumers, it is possible to make your own food dehydrator. An effective food dehydrator maintains a consistent temperature between 35 to 62.8 degrees Celsius.
When building a homemade food dehydrator, take special care with the food trays. While many do-it-yourselfers use kitchen screens for trays, as screens provide ample circulation and are easy to find, Scott Meyer's "The City Homesteader," warns against kitchen screens. According to Meyer, screens can contaminate foods due to the presence of certain metals. He recommends using ordinary oven racks, and wrapping them with cheesecloth.
Elements of a Homemade Food Dehydrator
Most food dehydrators have four basic elements: trays, housing, fan and heater. You arrange the food on the trays, which you put into the housing. The heater provides heat, the fan helps circulate the air, and the housing shelters the food trays and keeps the heat in the dehydrator.
There are many dehydrator plans available online. Charles Sanders give his plans for a wooden cabinet-like homemade dehydrator on the "Backwoods Home Magazine" website. The "Build it Solar" website offers plans and suggestions for solar-powered food dehydrators. Betsy Matheson's "DIY Projects for the Self-Sufficient Homeowner" gives an example of a homemade solar food dehydrator made from an old glass window sash. Solar dehydrators aren't a new concept. The October 1976 issue of "Popular Mechanics" includes plans for a solar dehydrator.
It isn't necessary to build an elaborate homemade food dehydrator to effectively dry vegetables, fruits and herbs. Ivette Soler's "The Edible Front Yard" suggests hanging herbs in a dry area of your home, in much the same way one dries a bouquet of flowers, upside down. Cover the bundle with cheesecloth to protect the herbs from pests and dust. Another suggestion is to spread sliced tomatoes on a clean screen and expose them to sun, for sundried tomatoes. Some try using an oven to dehydrate food, yet many ovens can't be set low enough to properly dry food. When using an oven, keep the door ajar and run a portable fan to assist in ventilation.