Counseling Sheet

Agatha M. Thrash, M.D.

Preventive Medicine

1. Dehydrating preserves food by removing enough moisture from the food to prevent spoilage.
2. Properly dried foods have a water content of 5% or less.
3. The weight loss of dehydrated foods varies greatly. Twenty pounds of fresh tomatoes weighs only 18 ounces when dried.
4. The most important fact to remember in dehydrating is that all produce must be fully ripe, firm, and flavorful. Fruits must be mature and sweet.
5. In order to dry properly, produce must be uniformly cut in slices ¼" thick or less.
6. The length of time required for fresh produce to dry varies according to the moisture content of the produce. Tomatoes may require 12-14 hours to dry, while mushrooms require 6-8 hours to dry.
7. Some foods, like apples, bananas, and potatoes, turn brown when exposed to the air. These foods may require treatment before drying to prevent darkening and loss of flavor or vitamins.
8. A proper balance of heat and air circulation is necessary for removing moisture from fresh produce.
9. Dried fruits will keep well, if properly stored in a cool, dark, dry place.
10. The flavor of dried foods is magnified many times from the fresh form because the water tends to dilute its full flavor.
11. Dehydrator trays must not be overcrowded. Slices are placed close together, but only one layer thick to allow good airflow.
12. The ideal temperature for dehydrating is around 120°. Temperatures should never exceed 140°, or unnecessary vitamin loss and scorching will result.
13. Strong-smelling foods, such as onions, should not be dried with other foods as flavors can be transferred.
14. Drying times may be affected by weather. On humid days, foods dry more slowly.
15. Dried foods may be stored in glass jars, paper bags, or plastic bags. To be safe, it is best to pack foods in airtight containers, such as coffee cans or tins.
16. Dried foods may be eaten as part of the meal. They may also be rehydrated by soaking in water for a short time then cooking as usual.
17. It is advisable to store dried foods in small containers so food is not frequently opened and resealed.
18. Only one item should be placed in each container. Flavors and odors may transfer.
19. Almost everything can be dehydrated, with the exception of foods that are high in oil or fat. Oil and fat will turn rancid.
20. Dried foods have the same calories as fresh. The nutrients are simply concentrated in a smaller area, but there is little change in caloric content.

(From Cooperative Extension Work in Agriculture and Home Economics, U.S. Dept. of Agriculture, University of California.)