Originally written by Hope Kleine, former SDSU Extension Health Education Field Specialist.
Drying or dehydrating gives you the ability to extend the life of your fresh foods to enjoy later. Starting with fresh, high-quality foods results in a tasty and nutritious product that can be eaten as a snack or added to a meal for your convenience.
About Food Dehydration
Drying or dehydrating food is one method of food preservation that removes enough moisture from the food so bacteria, yeast and molds cannot grow- making it important to never rush the drying process. To dry foods successfully, you need low humidity, low heat, and air circulation. Two common methods of drying food: are by using an electric dehydrator or an oven.
Electric Method
Electric dehydrators produce the best quality dried product due to their efficient design to dry foods uniformly while retaining food quality.
Oven Method
If an electric dehydrator is unavailable, drying in an oven will still result in a successfully dried product. Drying in an oven is slower, taking 2-3 times longer than a dehydrator, and uses more energy.
Drying Apples
To use your oven for drying apples:
- Use the keep warm setting on your oven and use an oven thermometer to ensure the temperature at the location of your food is 140 degrees. If the reading is above 140 degrees, your food will cook rather than dry.
- Peel, core and slice apples into approximately 1/8-inch thick slices. Treat with fruit fresh or ascorbic acid to prevent browning (optional).
- Arrange slices in a single layer on sheet pans.
- Leave the oven door propped open 2-4 inches and place a fan near the outside the oven door to improve air circulation.
- Dry 18-24 hours, rotating slices during the drying process.
Other Methods
Select foods, such as herbs, can also be dried by air drying or microwave drying. For more information, view this online guide courtesy of University of Minnesota Extension. Sun drying is not recommended in South Dakota.
Storing & Using Your Food
After your food is dried, store in air-tight containers. Check within 7-10 days to see if moisture is present. If you see moisture, remove food and re-dry. If food is moldy, discard it. Dried foods keep 4-12 months depending on storage conditions. For a longer shelf life, store in a cool, dry, dark place under 60 degrees F. While it is not necessary, dried food (except for meat jerky) can be stored in the fridge to extend shelf life.
To use your dried foods, fruits can be eaten as nutritious snacks or soaked in water for 1-2 hours to be used in recipes. To use dried vegetables, enjoy as vegetable chips, soak in water 1-2 hours, add directly to soups or stews, or make your own onion powder.
For a step-by-step process on drying foods, visit the National Center for Home Food Preservation.
