Start with firm, ripe apples (as many as you like), with a strong, tart flavor. Peel and core them; then slice them across the core into rings about ¼” thick.
Dry the apples as quickly as possible before they spoil. String the rings on a length of twine and hang it between any 2 hooks in a warm, dry, airy place. Drying can be done indoors or out. If outside, be sure the weather is sunny and dry, and bring the apples indoors if it becomes damp or rainy and during the nighttime dew. If flies or insects try to feed on your drying apple rings, cover them with a piece of cheesecloth. Outdoor drying during warm weather may take only a few days, whereas it may take up to two weeks to dry the apples indoors.
For indoor drying, hand the string of apple rings in the driest and warmest place in your house. Depending upon the time of year, this might be in your kitchen, by a radiator or heater, or in the attic. Don’t try to dry the rings in the oven, since heating them too quickly causes an outside skin to form and prevents the inside from drying.
Dried apple rings are usually eaten as a sweet snack, but they can also be put into cereals, cakes and other baking recipes. They can be carried and stored safely without refrigeration, which makes them a perfect snack on hikes or long car rides. They can be stored (for years!) in a jar with a tight lid without losing their flavor.