Dehydrating foods is the oldest method of food preservation. This process concentrates a food’s flavor and nutrition. It is important to control the temperature and allow for air circulation to prevent spoilage of food while drying.
A. 2 methods for safely drying foods at home:
• Using a thermostatically-controlled electric dehydrator
o Yields better quality
o Quicker drying time (vs. oven)
o If purchasing, things to consider:
? 1. Type of design. Air flow can be horizontal or vertical. Horizontal air flow allow you to prepare different foods at the same time with less flavor mixture and more equal heat penetration.
? 2. Needs to be an enclosed thermostat or temperature control that goes from 85 - 160°F.
? 3. It will be helpful to have easy-to-clean trays that provide good air circulation. Also, making fruit leathers requires a liner(s).
? A fan or blower provides needed air circulation to dry the product.
• Using either a gas or electric oven
o Heat oven to 140 - 145°F (use thermometer to check oven temperature for accuracy).
o Oven door needs to be kept open 2-4 inches for air circulation.
B. Good items to dehydrate
• Fruit: apples, cherries, grapes, peaches, pears, plums, bananas
• Fruit leather: bruised, overripe fruit
• Vegetables: beets, cabbage ,carrots, garlic, corn, peas, peppers, onions, mushrooms, tomatoes
• Herbs: gather when young and tender
• Meat: choose lean meat. Must be pre-treated using Marinade Brine or Hot Pickle Cure.
C. Preparing items
• Choose high quality produce, wash, and prepare soon after harvesting
• Fruits: Pre-treatment of lighter-colored fruits is important to prevent darkening
o Ascorbic acid (Vitamin C): commercial ascorbic acid crystals or Vitamin C tablets (1 teaspoon powdered ascorbic acid in 2 cups water)
o Commercial citric acid or lemon juice (commercial or equal parts lemon juice and water)
• Cut into thin, uniform slices for even drying
• Place dried foods in tightly closed container
• Stir or shake every day for a week (equalizes moisture)
• If food is still too moist, return to dryer
Iowa State University Extension and Outreach’s Food preservation resources: http://www.extension.iastate.edu/humansciences/preserve-resources
Iowa State University Extension and Outreach’s AnswerLine: 1-800-262-3804 or firstname.lastname@example.org