A combination of these methods, especially the two latter, is often used in drying foods.
Plates or dishes may serve as driers when the drying is done in the oven. Trays for drying may be constructed at home or they may be purchased. Most of them consist of a wood or metal frame over which wire netting is tacked. Single trays or a series of trays one placed above the other may serve as driers. When drying is accomplished by heat from a stove, the drier is hung over a stove or it rests on the top of the stove. In the latter case, it is necessary that the frame of the tray be constructed so that the bottom tray does not rest directly on the stove. In case the drying is done over a kerosene stove, the bottom of the tray must be of tin or galvanized iron to protect the food from kerosene fumes. The lowest tray must be placed at least 4 inches above the metal bottom.
SELECTION AND PREPARATION OF VEGETABLES FOR DRYING.—To secure the best results, select mature but fresh vegetables. They should be in good condition, free from blemish.
Certain foods, such as berries, cherries, peas, lima and shell beans, are dried whole. Most vegetables should be cut into slices from 1/8 to 1/4 inch in thickness. The slicing may be done with a paring or kitchen knife, or it may be done by means of a slaw-cutter or a rotary chopper. Foods are sometimes cut into pieces for drying by means of the food chopper. It is necessary that all knives and cutting devices be clean. There should be no discoloration of the vegetable from the cutting utensil. It has been found advisable to blanch most vegetables before drying. The method of blanching given previously can be used in drying vegetables as well as canning them. Foods are not cold-dipped, however, after blanching when they are to be dried. Fruits are usually not blanched before drying.
FOOD PRESERVATION
METHOD OF DRYING FOODS.—Place the prepared food on drying trays. Unless the drying is done in the oven, cover the food with cheese-cloth. If possible, tack the cloth to the frame so that no dust or insects can come in contact with the food. Stir or turn foods once or twice a day while they are drying. This is especially necessary when foods are dried in the sun.
If the food is to be dried in the sun, place the tray containing the food in the sun, where there is a breeze. If it rains, take the trays indoors. Also bring the trays indoors just before sunset.
If food is to be dried by means of steam, a special device is needed (see Figure 93). The device consists of a large pan for holding water and a hollow tray. The under surface of the tray has an opening about the size of the diameter of the pan. To this opening is fastened a collar which fits snugly into the pan. The pan filled with water is placed over a burner. When the water boils, the steam rises and fills the hollow tray and escapes by means of the small pipe in the upper surface of the tray. The food is placed on the upper surface and is dried by steam heat.
If the food is to be dried in the oven, place the food on suitable trays. Oven drying is much more satisfactorily done if the oven is provided with a thermometer. The temperature for drying foods is much less than that of boiling water,—it varies from 115 degrees to 175 degrees F. It is often necessary to keep the oven door open so that the temperature does not become too high.
[Illustration: FIGURE 93.—-DRIER FOR VEGETABLES OR FRUITS.]