The Ronco corporation produces two food dehydrator models, and both rely on convection heat to remove most of the moisture from meats, fruits and vegetables. All models feature a removable lid equipped with vents that must be left open during the entire procedure, which can take roughly two to three days to complete, depending on the foods you are dehydrating.
The Ronco food dehydrator, built entirely of plastic, is available in five-tray and seven-tray units that heat the food using a small light bulb located in the bottom under the lowest tray. Instructions recommend leaving the top vent open at all times to provide an exit point for the moisture being drawn from the food and allow the heat to escape. There are no settings for the top vents. They are left either fully open or closed, and the lid fits easily onto the top tray.
When using the Ronco food dehydrator for the first time, wash all trays and the lid in warm soapy water to remove any manufacturing residues and dry completely. Place the unit on a firm surface near an electrical outlet and place sliced foods on each tray according to your preference. Place foods close together but not overlapping, as this slows drying time. Stack trays on top of each other and place the lid on top. Open the vents and plug the unit in. Rotate the trays throughout the process to assure that all foods are exposed to the most direct heat. Check foods from time to time until they have reached the desired dryness. Vegetable slices should be dry and crispy, and fruit or meat pieces should be dry, soft and pliable. Store dehydrated foods in airtight, insect-proof containers such as clean, dry jars or resealable plastic containers or bags.
When compared to other, more sophisticated dehydrators, the Ronco has several drawbacks, the most significant being the lack of a fan to circulate the air. This greatly adds to the drying time and necessitates shifting the food around to assure maximum exposure to the heat source. The Ronco also does not offer a heat control. The unit is simply plugged in and allowed to warm gradually to its maximum temperature of roughly 130 degrees F., and there are no detailed instructions on how to assemble the unit, turn it on or adjust the top or bottom vents.
Considering its drawbacks, the Ronco is a good first choice for anyone new to food dehydration or anyone with only a casual interest in the process who isn't interested in investing a lot of money in it. It's easy to clean and store, and the choice of five or seven trays allows you to process varying amounts of food based on your personal usage. Always start with clean, good-quality produce, and keep records of how long it takes for each item to dry. Drying is not an exact art, as each piece of food dries according to how much moisture it contains. The smaller the pieces, the shorter the drying time.