One of the easiest fruits to dehydrate, apples can be dried long enough to turn them crispy, like potato chips. They make a healthy snack that can be stored for a long time without refrigeration. If desired, they can be rehydrated by covering with boiling water and soaking until fully moistened, about 15 to 20 minutes.
Choose firm, ripe, blemish-free apples for dehydrating. Fully ripe fruit makes the best tasting dehydrated product because the sugars are fully developed.
Wash the fruit well and air dry, or dry with a clean towel.
Stir 1 tsp. citric acid into 1 qt. cold water in a large bowl. Alternatively, mix equal parts of lemon juice and cold water in a large bowl. Either of these preparations are sufficient to pre-treat the fruit to prevent darkening, facilitate drying and enhance the destruction of harmful bacteria during the drying process.
Slice apples either peeled or unpeeled, depending on your preference, but remove the core and seeds prior to slicing. Peeled apples keep their shape better, but unpeeled apple slices have a better mouth-feel when eating the finished product. Ensure that the slices are relatively equal in width, to facilitate drying. Apple slices for apple chips should be sliced as thin as possible, approximately 1/8 inch.
Place sliced apples immediately into the citric acid or lemon juice bath. Allow them to soak for about 10 minutes. Remove from the solution with a slotted spoon and place on bakers' racks to dry prior to loading into the dehydrator.
Place apple slices in a single layer in the dehydrator. Apple slices will dry to a leathery consistency in about 6 hours and turn crispy in about 8 to 10 hours. Turn the fruit over and rearrange every 3 to 4 hours for even drying.
Remove the apple slices from dehydrator, place on racks and allow to cool to room temperature.
Condition the fruit by loosely packing into large glass jars when it has cooled to room temperature. Fill the jars about two-thirds full. Cover but do not tighten the lid. Allow the jars to sit in a warm, dry and well-ventilated area from 4 to 10 days. Shake or stir the contents daily to separate the pieces and ensure they are thoroughly dry.
Pack fully conditioned dried apple chips into small glass jars or plastic bags for permanent storage. Label with contents and date packed.