What is food dehydration and why do it?

Drying or dehydrating food involves removing its water content to a point where the food is preserved for a longer time than if left fresh. The lack of water prevents microorganisms, such as mold, from decomposing the food. Foods also contain enzymes, which are naturally occurring proteins involved in the growth of the plant, that slow down when a food is dried and help lengthen the food’s shelf life.

Drying temperatures

Drying of foods occurs best around 140°F. At higher temperatures, foods tend to cook rather than dry. How dry should foods be? Dried fruits should reach 20% moisture and be pliable, but not sticky. Dried vegetables will be brittle or crisp, with a moisture level of 10%.

Drying Methods

• Electric food dehydrators
  Food dehydrators are an electric appliance. Both horizontal and vertical dehydrators are effective and hold racks or trays of food to be dried. With a fan, warm air blows through and around the food, helping to remove moisture.

• Oven and microwave drying
  Drying using an oven or microwave is useful for households that only want to dry occasionally and in small batches. When using an oven to dry, make sure the oven can maintain a low temperature of 140°F. If so, proceed with drying. Keeping the oven door open slightly and having a fan blowing at the oven can help create a similar environment to an electric food dehydrator.

• Microwave drying
  Microwave drying is only recommended for herbs.

• Sun drying
  Sun drying is acceptable for fruits, but not vegetables or meats. Ideal conditions for drying (temperature, humidity, lack of rain, etc.) are hard to maintain. Sun-dried foods also require pasteurization to destroy insects or eggs that may be present.

• Solar drying
  Solar drying uses a foil surface to increase the temperature where the food is being dried and shortens drying times.

• Vine drying
  Vine drying is used for legumes and other dry beans. Simply leave the vine alone to let the pods dry and shrivel before harvesting.

• Air drying
  Air drying indoors works well for hot peppers and herbs. Create a bundle of hot peppers or herbs and tie together with string. Leave in a well-ventilated area until the food dries completely. Consider covering food bundles with a paper bag poked with holes to prevent dust from gathering on the food’s surface. Drying outside can lead to a loss of flavor and color.

Looking for full instructions, including recipes for pumpkin leather, jerky, and jerky marinade? Read our Drying Foods at Home Guide.