There's another natural method you've likely seen but maybe didn't connect with dehydrating. Traditional New Mexican ristras are strings of chilis that can hang in the sun, under cover, or indoors, until dried. "When you hang them, you just hang them," says Jinich. Use strong thread or fishing line to string the chilies, directly under the stem. Make a knot to leave space between each one. Hang, and don't expect them to be ready for at least three weeks. Jinich uses dried chilis throughout her cooking, including blending anchos (dried poblanos) into ground beef to make a Mexican twist on hamburgers.
Advantages to using the sun: the bright resulting colors and possibilities of batches bigger than can be done in ovens and dehydrators. But DeLong points out disadvantages, too: Nutrients are lost from the lengthy exposure to sun and air, and foods are less sanitary than those dried in the oven or a dehydrator.
DeLong, a home economics teacher before she turned her attention to dehydrating, has traveled the world teaching best practices to countless people in varying cultures. While Friedman says a home oven is a fine option ("You just need a little more time"), DeLong prefers a dedicated machine. Though fine for someone experimenting, "An oven should be a last resort unless you have a convection with a very low temperature."
Convection ovens have a fan to move air, and an outlet to remove moisture. Exhaust systems are helpful too, so you don't have to leave the door open. But the difficulty of controlling temperature and air circulation can produce darker, less flavorful results.
While produce is easy and relatively safe to dry, the technique needn't be limited to fruits and vegetables. At the Red Hen, Friedman dehydrates ricotta salata (a semi-firm sheep's milk cheese whose curds and whey are pressed and dried before aging) so he can grate it. At the Pig - where they buy whole animals and try to avoid waste - Bonk dehydrates skin to make cracklings. "The process is pretty straightforward," he says, "but it took me several attempts to understand the nuances of pork rinds to get consistent results." Unlike produce, meats need to be first cooked to a temperature that kills bacteria and then kept at a certain temperature for drying safely.