Fruits picked at their prime have the highest natural sugar content and best nutritional value. For best quality product, choose only fresh, ripe, unblemished fruits.
Wash fruit thoroughly and remove any imperfections. Remove skins (if desired), stems, and stones. Halve or slice in 1/4" to 1/2" circles or slices (a food processor or slicer will speed slicing and ensure more uniform slices, which will allow fruits to dry at the same rate.)
Some fruits have a natural protective wax coating such as figs, prunes, grapes, blueberries, cranberries, etc. If you want to dry these fruits whole, dip into boiling water for 1 to 2 minutes (amount of time needed depends on thickness and toughness of skin) to speed dehydration. This makes skin more porous by removing the natural wax coating and thereby speeds up drying time. Small lines appear on fruit skin allowing moisture to escape but may be too fine to be visible. Many fruits can be dried in halves with the pits removed. If drying with skins on, make sure to dry skin side down to prevent juice and pulp from dripping down through trays. Check frequently near end of drying process and remove pieces as they become dry. If fruit has been artificially waxed, it should definitely be peeled to remove wax. Pre-treat, if desired, and place fruit into preheated dehydrator at 135° F (57°C).
Should You Pre-Treat?
Pre-treatment isn't necessary for most fruit. The majority of fruits are simply sliced and dried. However, some fruits tend to oxidize more than others. Oxidation causes browning of cut food surfaces when fruit is dried. This causes a loss in flavor and vitamins A and C. Pre-treatment minimizes oxidation. Apples, pears, peaches and apricots are better when pre-treated before drying. To pre-treat, place cut fruit in a holding solution of ascorbic acid to reduce browning during preparation. DO NOT keep cut fruit in a holding solution for more than an hour.
Pre-treatments can vary from soaking in fruit juice [such as pineapple, orange, lemon or lime], ascorbic acid mixtures, syrup blanching, steaming, to sulfiting. The results of these methods also vary. Experiment and decide for yourself which one you like best.
Fruit Juices containing ascorbic acid may be used as a natural pre-treatment to reduce browning. Although there will still be some loss of color, pineapple, orange, lemon or lime juice can be used. Ascorbic acid mixtures, available at your supermarket, can also be used. Follow directions on package.
Slice fruit directly into juice or ascorbic acid mixture. Soak 5 minutes and place on trays. Fruits can also be dipped in honey or a honey/fruit mixture.
Fruit which has been syrup blanched is sweeter because it absorbs some of sugar from blanching solution. It also tends to be stickier, even though it is rinsed prior to drying.
Prepare sugar syrup by mixing 1 cup sugar, 1 cup white corn syrup, and 2 cups water. Boil and add prepared fruit. Simmer 10 minutes over low heat. Remove and allow to stand in hot syrup for 30 to 45 minutes. Drain fruit, rinse lightly with cold water, and place on drying trays.
Soaking fruits in a solution of sodium bisulfite slows oxidation and reduces browning, as well as the loss of vitamins A and C. Sodium bisulfite may be obtained from wine-making supply houses. Sulfating is not recommended for use if individuals are on restricted sodium diets or have asthmatic or respiratory conditions.
Dissolve: 1 tablespoon sodium bisulfite in 1 gallon water. Soak 5 to10 minutes. Rinse.
After fruits have been prepared for drying, garnish with spices, gelatin powders or coconut to give fruits a snappy flavor. Granola, chopped nuts, poppy seeds, sesame seeds or sunflower seeds can also be sprinkled on fruits. These adhere best to fresh fruits if fruits have first been dipped in fruit juice or honey. Use your imagination for other dips or sprinkles.
Moisture will tend to equalize throughout a container of dried fruit when left at room temperature for several days. If some pieces are drier than others, the conditioning process will allow moisture to equalize. If any condensation appears on lid of container, fruits are insufficently dried. Return to dehydrator and check periodically for dryness.
Hints and Suggestions
Fruit Rolls (Fruit Leathers)
Fruit Rolls, also known as Fruit Leathers, are a chewy fruit product made from pureed fruit which has been dried and rolled into snack-sized pieces. Fruit Rolls are easy to make and cost less than those in stores.
Almost any fruit will make an excellent fruit roll. Most fruits can be combined with others. The combinations are limitless. Some fruits, such as apples, are high in pectin and fiber and have an excellent texture when dried.
You can use fresh fruits, slightly overripe, irregularly shaped or even slightly bruised fruits. Some fruits, such as citrus, should be used in combination with other fruits because they have so much liquid and very little pulp. If you find a fruit too runny, combine it with apples, applesauce or a similar fruit which will give it more substance. When fresh fruits are not available, canned fruits may be used (either sweetened or un-sweetened). Drain liquid, and pour fruit into a blender. Applesauce can be taken directly from container. Frozen fruits can also be used, although they tend to be a bit more runny. First thaw fruit and then follow directions for using fresh fruits.
Wash fruits and cut away any bruised or spoiled portions. Puree fruit in a blender until it is very smooth. In some blenders with some fruits, you may want to add a little juice or water to start blending process. Fruits generally need no added sweetening, but if fruits are under ripe or particularly tart, you may add light corn syrup or honey. Add 1 or more tablespoons sweetening for each quart of puree, depending on preference (sugar added to fruit leather tends to become brittle during storage).
For added variety, sprinkle different garnishes on fruit rolls before they are dried.
Place Fruit Roll Sheet on dehydrator tray and wipe lightly with vegetable oil to prevent sticking. Puree should be about 1/4" to 3/8" thick and evenly spread. Dry at 130° - 140° F (55°-60°C) until fruit feels leather-like and is pliable, approximately 4 to 8 hours. There should be no sticky spots on top or underneath fruit. Remove leather while it is still warm, roll, cut into smaller sized pieces (if desired) and wrap in plastic wrap.
Individually wrapped pieces of fruit leather should be stored in larger airtight and moisture proof containers.