Tempermental foods are those fruits and vegetables that mold or darken easily while drying. Apricots and tomatoes are the most notable of these, but it is also true of any very ripe, juicy, or easily bruised food. These foods require special understanding and careful handling.
TOMATOES AND APRICOTS ARE MOSTLY WATER. Tomatoes have a moisture content of about 94% and apricots about 85%. In other words, almost nine and a half pounds of water must be extracted from ten pounds of tomatoes. These foods release more moisture than can escape quickly from the dehydrator. This warm, moist atmosphere is conducive to mold and spoilage.
TEMPERMENTAL FOODS REQUIRE SPECIAL HANDLING.
DO NOT USE OVER-RIPE FRUIT. Produce should be ripe and firm enough to slice neatly and and easily. Do not postpone drying tomatoes and apricots. Soft or over-ripe fruit can be pureed and used for leathers.
SLICE IN THIN SLICES OR WEDGES. We slice our tomatoes as thinly as we can, about an eighth of an inch thick. With apricots we have found that thin wedges work the best. Remember that most of the soft apricot halves that are available in stores have been sulfured and blanched to keep their color and moistness. We do neither. Slice food directly on to screen. Tray liners make removal of dried food easier.
NOTES: Don't slice ON the screen, knives will cut it. Slice above the screen and drop the food directly onto the screen as it is cut. A tray liner is a loose piece of tray screening laid in the tray. Food is put on top of it and can be lifted out more easily. This is not mandatory, just an extra bit that can make life easier at times.
DO NOT OVERLOAD DEHYDRATOR. When using a convection dryer such as the Living Foods Dehydrator, we recommend using only the bottom three trays. If you use more trays, do so cautiously. Be sure not to slow drying process too much. With other types of dehydrators, fill trays only half full.
DRY QUICKLY BUT NOT TOO HOT. We dry both tomatoes and aprictos at about 110° F. They dry quickly, usually in 18 to 30 hours. Remove as soon as dry.