Food dehydration is likely the oldest form of food preservation. In food dehydration, water is removed from the food. With the water removed, mold and bacteria cannot grow and thus the food will not spoil. Additionally, dehydrated fruits and vegetables retain much more of their nutrients and flavor than canned or even frozen produce.
Food dehydration can also help you save money and avoid waste. You can dehydrate surplus produce from your own garden and fruit trees for use later in the year. It also allows you to take advantage of great sales at the grocery store or other bulk purchases. This low priced produce can be preserved for the “off” season when prices will be much higher.
Methods of Dehydration
Sun Drying: Possible to do, but requires several days of at least 100°F in a row and works best in areas with low humidity.
Oven Drying: Acceptable, but not energy efficient. Many ovens can’t obtain the proper low temperatures, and you will need to prop the oven door open to maintain air circulation during the drying process.
Electric Dehydrating: The best method of dehydrating food. Electric dehydrators are energy efficient and can maintain proper temperatures and air circulation.
The Drying Process
It is critical to read the operating manual for the food dehydrator that you own as each model varies. Here are some general guidelines that will aid you in the drying process.
Vegetable Drying Guide
All vegetables except onions, garlic, mushrooms, and peppers should be washed, sliced, and blanched before drying. Blanching stops enzyme action that would otherwise cause loss of color and flavor during drying and storage. It also shortens the drying time and rehydration time by relaxing the tissue walls so moisture can escape and later re-enter more easily.
To Steam Blanch: Add about 1” of water to a pot then place a steamer basket over the water. Bring water to a rolling boil then place vegetables loosely in the basket no more than 2” deep. Cover the pot and steam for 1/3 of the amount of time it would take to cook the vegetables.
Once prepared and blanched, arrange vegetables in a single layer on drying trays. Dry vegetables in the dehydrator at 140°F until brittle.
Fruit Drying Guide
In general, fruits should be washed, pitted, and sliced. Some fruits like grapes, cranberries, and blueberries have a waxy skin that prevents moisture from escaping. These fruits must be dipped in boiling water just long enough to crack their skins before they can be dehydrated. Fruits such as apples, pears, bananas, apricots, peaches, and nectarines will darken in color and lose vitamins while drying if not pretreated to stop oxidation.
To Pretreat: Drop sliced fruit into a solution of ¼ c. lemon juice to 2 cups water and soak for 3-5 minutes before placing on drying racks. As an alternative, fruits may instead be soaked directly in pineapple, orange, or lime juice, or in an absorbic acid solution.
Dry fruits at 135°F until leathery and pliable with no moisture pockets. To test, tear a piece in half, pinch, and watch for moisture drops along the tear. If no moisture appears, then it is sufficiently dry for long term storage.
Fruit Leathers
Most dehydrators come with fruit leather trays to make homemade fruit roll-ups. To make fruit leather, simply puree your fruit in the blender before dehydrating. Applesauce works great for fruit leather since it is already in puree form. Overripe fruits can also be used since these are easily pureed. Apples, pears, peaches, and nectarines may be cooked before pureeing. Add 2 teaspoons lemon juice or 1/8 teaspoon ascorbic acid for each two cups of light colored fruit to prevent darkening. You may add honey or light corn syrup to sweeten your fruit leather, if desired. Pour the fruit puree about ¼ inch deep onto a fruit leather drying tray that has been lightly coated with nonstick cooking spray. Dry at 135°F for 4 to 8 hours until pliable and leathery. The center should also be dry and have no wet or sticky spots.
Storage of Dehydrated Fruits and Vegetables
Dehydrated foods should be packaged immediately after drying or they will begin to absorb moisture from the air. They must be stored in an airtight, moisture proof container (examples include ziploc freezer bags, well sealed tupperware containers, or glass jars with a tight fitting lid). Dried foods will keep the longest when stored at temperatures of 60°F or below in a dark, dry location. Storage in the refrigerator or freezer is recommended for long term storage. Vacuum sealing your dried foods can extend the shelf life by 3 to 4 times. Label your packaging with the type of food and date dried.
