These increased energy costs and the fact that the oven may be needed for everyday cooking mean the oven may not be the best choice for drying large quantities of product. A food dehydrator is a small electrical appliance for drying foods. Most dehydrators consist of an electric element for heat, a fan to cause air movement, vents, and trays for holding the food. Some models come with a limited number of trays, but additional trays are available to expand drying capabilities. Successful drying of vegetables is generally not possible in a microwave oven.
Microwave heating tends to overcook foods before they are dried completely.
Leave bean pods on the vine in the garden until the beans inside rattle. When the vines and pods are dry and shriveled, pick the beans and shell them. If beans are still moist, complete drying in the oven or a dehydrator to prevent molding. No pretreatment is necessary before completing drying. The kind of equipment you need for drying depends on the drying method you use.