Air Dried Dehydrated Foods are less expensive than freeze-dried, as much as 50% less for some items. Air drying causes the foods to shrink, making it possible to put more food in a can, taking up less storage space. Air Dried foods store well after opening if a tight plastic lid is kept on the can. Minimum storage for such items as powdered butter is 4 months and if kept in the refrigerator, 6 months or more. Fruits and vegetables are even longer lasting with 1 year being possible.