Food dehydrator A food dehydrator is an essential kitchen appliance designed to preserve food by removing moisture through a drying process. Consisting of trays, a heating element, and a fan, the dehydrator works by circulating warm air evenly across the food, gradually drying it without cooking or damaging its nutritional content. The versatility of a food dehydrator extends to a wide range of foods, including fruits, vegetables, meats, herbs, and even dairy products.