Eggplant lends itself well to drying, and the dehydrated slices are ready to use in a variety of dishes, including meatloaf, meatballs, soups and chili. An electric dehydrator is the easiest way to dehydrate eggplant, but you can also use an oven. According to University of Georgia Cooperative Extension, sun-drying is not a safe method because of the risk of spoilage.
Wash and Slice
To prepare eggplant for dehydration, wash it under cool water to remove surface dirt, then use a serrated knife to remove the green top before slicing. The best size for drying is sliced rounds about 1/4-inch thick. Young, tender eggplant are preferred for drying, and they require no peeling.
Blanch for Best Flavor
Blanching is necessary to halt the enzyme action that causes loss of flavor and color during the drying process. It also shortens the dehydration time. You can blanch eggplant in boiling water, but steaming is the preferred method because more nutrients are retained, according to Purdue University Extension. Use a deep pot with a wire basket or colander and a tight lid. Place several inches of water in the pot and bring the water to a full boil. Layer up to 2 inches of eggplant slices in the wire basket, then place the basket in the pot. Be sure the vegetables are above the water. After the eggplant steams for 3 1/2 to 4 minutes, plunge the basket briefly in cold water to stop the cooking. When the slices are still slightly hot to the touch, remove the basket from the water and let the slices drain thoroughly.
In the Dehydrator
Spray the dehydrator trays with nonstick cooking spray, then arrange the drained eggplant slices on the trays in a single layer with no overlap. Preheat the dehydrator to 140 degrees Fahrenheit and place the trays inside. Rotate the trays from top to bottom every two hours, until the slices are brittle or leathery, depending on your preference. The dehydrating time for eggplant is 12 to 14 hours.
In the Oven
Dehydrating eggplant in the oven requires special attention and is only possible if you can set your oven temperature to 140 degrees Fahrenheit. Arrange the slices on trays in single layers, then place the trays on the oven racks. To prevent crowding, be sure there is about 2 inches between each rack and at least 3 inches of clearance at the top and bottom of the oven. Place an oven thermometer on a tray in the center of the oven and check the temperature often. A temperature of 140 to 150 degrees is critical, so you may need to prop the door open with a potholder to prevent overheating. Rotate the trays from front to back and top to bottom every 30 minutes. When the slices are nearly dry and no longer sticky, turn off the heat and open the door wide, then let the eggplant finish drying for about an hour. Oven-drying can take as long as 14 to 20 hours.