Before deciding to buy a dehydrator, some people experiment with other drying methods. Yes, you can dry food in the sun, as our ancestors did, but only in the most perfect of weather conditions (and absence of pests). You can dry using a homemade machine, or in your oven, but the results will be inferior to using a device designed specifically for dehydrating. If you use a home oven, there is no system for circulating dry air, and food will dry at uneven rates and temperatures. Your oven will be monopolized for hours or days, and the oven door must be left slightly open, which wastes energy.
Though small, inexpensive dehydrators can sometimes be found at department stores, if you are serious about preserving food in large quantities and for long periods of time, you should probably invest in a quality model. The easiest way to find one is to perform an online search. Excalibur and L’Equip are popular quality models.
You should look for a dehydrator with its heating element on the back or side, with a fan for circulating dry air through the system. Dehydrators with heating elements at the bottom don’t produce a uniform drying environment and yield inferior results (similar to using a home oven). Look for a dehydrator with a thermostat control.
Optimal temperature for dehydrating foods while maintaining their nutritional value is between 115 and 120 degrees. Find out what the trays inside are made of. Fiberglass or stainless steel trays are safest. Plastic may melt at high temperatures. If trays in a low-temperature dehydrator are made of plastic, make sure that it is nontoxic plastic, as it could accidentally leach into the food if the temperature rises too high.
Also consider your own personal preferences. If you will be dehydrating large quantities of food, buy a model with eight or nine trays. If you will be drying small quantities only, you may prefer a five-tray model. Consider where you will keep the dehydrator, and how much counter space you have.
At the recommended lower dehydrating temperatures, the dehydrator becomes warm to the touch, but not hot enough to burn anyone. It can be left running for at least three days at a time. Dehydrator fans generate a low hum, like other fans, but the sound is not likely to be bothersome in your home.