Cut the ends off the onions, then slice the onions in half, remove the outer edge of the skins. Then slice and chop into desired pieces. Set your dehydrator on your dehydrator models suggested temperature. My Excalibur Dehydrator states 155 degrees. These took about 10 hours to dehydrate them. The time will always depend on the humidity of the room you are using to dry your food. Dehydrate them until they are leathery. Let them dry another two weeks until totally dry before placing them in mason jars to seal by using use your FoodSaver. These will keep for one year in your pantry. Use the dehydrated onions to make onion powder. Place a small amount of the dry onions in a blender to pulverize them into powder. Only make powder for the month you will use it because it will lose the strong onion flavor rather quickly.