Drying is one of the oldest methods of food preservation, and methods for drying foods have become more sophisticated over time. There has been renewed interest in this form of food preservation and people are rediscovering drying foods at home.
Drying removes the water from food, which is how properly dried and stored foods last for so long. Microorganisms that cause food to spoil can’t survive with less moisture.
Drying doesn’t improve the quality of fruits or vegetables, so it is important to choose produce of high quality and at the desired stage of ripeness. Most fruits need pre-treatment before drying to reduce vitamin loss, flavor loss, browning and deterioration during storage.
Foods can be dried in the sun or in a solar dryer, but using an oven or electric dehydrator is more reliable than depending on the weather. Temperatures and humidity levels can be unpredictable, so food may sour or mold before drying is completed.
An electric dehydrator uses warm air and good air circulation to remove moisture from food. A drying temperature of 140 degrees F is recommended and drying times vary from a few hours to a full day. Times depend on the moisture content, amount of food, room temperature and humidity.
The temperature in the back car window on a hot summer day can far exceed the recommended drying temperature and there certainly isn’t good air circulation that is needed for proper drying. You may end up with cooked fruit, not dried fruit. If the food cooks on the outside and moisture can’t escape, the food can mold.
Remember that drying is a form of food preservation. As with any food preservation method, safe practices are the key. See Quality for Keeps: How to Dry Foods at Home for more information.
Visit the MissouriFamilies website for more information about nutrition and food preservation.
Contributor: Karen Sherbondy, MEd, RD, LD, Extension Associate, Nutrition and Exercise Physiology, University of Missouri Extension, 816-655-6227