For thousands of years, people have dried many foods to preserve them for leaner times. Preserving seasonal foods by drying is still useful and convenient, and it has the added advantage of conserving storage space. How does drying preserve food? Basically, sufficient moisture is removed from a food material to prevent its decay; water content of properly dried food can vary from 5 percent to 25 percent. In hot, dry climates, food will be reduced in a few days to a moisture level that preserves them. In any climate, however, you can create satisfactory drying conditions at a moderate expense by using artificial heat and circulating air over the food.

Select your vegetables carefully. If they are not fresh and are not in prime condition for cooking, they are not suitable for drying. Vegetables should be washed and prepared on the same day they are harvested.

Blanching is the process of heating vegetables sufficiently to inactivate enzymes. Enzymes are the biological catalysts that facilitate chemical reactions in living tissue. If certain enzymes are not inactivated, they will cause color and flavor to deteriorate during drying and storage. Blanched vegetables, when dried, will have better flavor and color than unblanched ones. You may blanch with hot water or with steam. Water blanching usually results in more leaching of vegetable solids, but it takes less time than steam blanching under kitchen conditions.

With steam: You need a kettle with a tight fitting lid to use as a steaming container, a colander, wire basket, or sieve that will fit in the kettle. Add 1 1/2 to 2 inches of water to the steamer, and heat to boiling. Place the colander, basket, or sieve containing loosely packed vegetables into the steamer and leave until the vegetables are heated through and wilted. Test by cutting through a piece of food. If sufficiently blanched, it should appear cooked (translucent) nearly to the center.

With water: Use only enough water to cover the product. Bring the water to a boil and gradually stir in the vegetable. Re-use the same water for additional lots when blanching the same vegetable, adding new water as necessary. Keep the lid on the kettle while blanching.

Drying in the kitchen oven or in a dehydrator is recommended; however, sun drying may be used under proper conditions.

1. Trays must be at least 1-1/2 inches narrower than the inside of the oven to allow for air circulation. Allow at least 2-1/2 inches between trays and 3 inches of free space at the top of the oven. Cheesecloth may be spread over the trays (under the food) to prevent small pieces from falling between the slats.

2. Load two to four trays with no more than 4 to 6 pounds of prepared vegetables distributed among them. Vegetable pieces should be in a single layer. More than one kind of vegetable can be dried at the same time. Strong-smelling vegetables should be dried separately.

3. Place an accurate and easily read thermometer on the top tray toward the back.

4. Preheat the oven to 160 degrees F (71 degrees C), and then add the loaded trays. Prop the door open at least 4 inches.

5. Place a fan outside the oven in such a position that air is directed through the opening and across the oven. Change the position of the fan frequently during drying to vary the circulation of air.

6. Maintain the temperature at 140 degrees F (60 degrees C). It takes less heat to keep the temperature at 140 degrees F as drying progresses, so watch the temperature carefully toward the end of the drying.

7. Examine the vegetables often, and turn the trays frequently. At the start of the drying process there is little danger of scorching, but when nearly dry, the product may scorch easily. Even slight scorching destroys the flavor and may lower the nutritive value, so be careful not to allow the temperature to rise above 140 degrees F, especially during the latter stage of drying.

Drying in the sun is unpredictable unless temperatures are over 100 Degrees F, and the relative humidity is low. If the temperature is too low, humidity too high, or both, spoilage (souring or molding) will occur before drying is achieved.

Place the prepared vegetables on clean trays, as for dehydrator drying, and cover the trays with cheesecloth to guard against insects.

The trays should not be stacked for sun drying. The cheesecloth should be raised above the trays so that it does not contact the product, but be sure to protect the sides against insects. Such a cover will slow the drying process.

Turn the vegetables once a day to facilitate drying. If the temperature at night is more than 20 degrees F lower than daytime temperature, place the trays under shelter. It will probably take 3 to 4 days to complete drying, depending upon particle size, air temperature, and type of product.

PACKAGING

Dehydrated vegetables are free from insect infestation when removed from the dehydrator or oven. However, they are immediately susceptible to contamination and should be packaged as soon as they are cool. Use dry, scalded, insect-proof containers such as home canning jars with well-fitting lids. Coffee cans may be used if the dried vegetables are first placed in a plastic bag. The vegetable should be packed into the container as tightly as possible without crushing. Despite precautions, sun dried vegetables may be contaminated by insects. Therefore, the packaged dried vegetables should be placed in the home freezer for 48 hours to kill any possible insects or their eggs. Containers and storage areas should also be rodent proof.

Containers of dried vegetables should be stored in a dry, and dark place. Low storage temperatures extend the shelf life of the dried product. All dried vegetables deteriorate to some extent during storage, losing vitamins, flavor, color, and aroma. For this reason, they will not retain their appeal indefinitely. Carrots, onions, and cabbages deteriorate at more rapid rates than do other vegetable, and will generally have a shelf life of only 6 months. Some vegetables, however , will be good after a years storage.

Drying does not improve the quality of fruit. For this reason, use only fully ripened fruit. If it is not suitable for eating fresh, it is not suitable for drying.

PRE DRYING TREATMENT

Sort and discard defective fruits. Wash, pit, and halve when necessary (as with stone fruits). Most fruit must be treated (immediately before drying) to maintain an appetizing appearance - and to prevent darkening, loss of flavor and vitamin C.

SULFURING: materials you need

Trays, slatted, wooden. Do not use aluminum or galvanized screening material, as sulfur fumes corrode most metals. If wooden slatted trays are not available, wooden lids from boxes may be used.

Thread spools, wooden or plastic (not styrofoam) or small, wooden blocks. Place at corners of trays to stack them 1-1/2 inches apart.

Box, heavy cardboard or wooden no cracks or openings). Must be large enough to place over stacked trays with 1 to 1-1/2 inches to spare between trays and inside of box. Box should also be large enough to accommodate the container of burning sulfur under the stacked trays.

Fire Bricks to raise the stack of trays high enough off the ground to accommodate the container of burning sulfur.

Sulfur. Use elemental sulfur also called Sulfur Flowers (U.S.P. standard) or flowers of sulfur. It is free of impurities, burns readily, and may be purchased at most pharmacies. Sulfur preparations for garden dusting may be used if they are 95 percent sulfur with only 5 percent impurities. However, these preparations are more difficult to ignite and may require the use of a torch to get them started. This sulfur may be purchased at a nursery, garden supply shop, or a feed supply store.

Clean, metal container to hold the sulfur. For small amounts of fruit, a one pound coffee can or an aluminum pie tine will be large enough.

HOW TO DO IT:

Always sulfur outdoors away from close contact with plants, shrubs, and trees. For specific sulfuring periods consult the University of California’s publication on drying foods (#2785).

1. Spread fruits in a single layer, pit cavity side or cut surfaces up, on trays. Pieces should not touch each other.

2. Stack trays 1-1/2 inches apart, separated by spools placed at the corners.

3. Cover the stacked trays with the box. Make a slash at the bottom of the box and another slash at the upper edge of the opposite side. Open slashes when necessary to permit circulation of sulfur fumes.

4. Measure the sulfur and place it in the container. The amount used varies with the length of time the fruit is to be sulfured, weight of the fruit, and the dimensions of the box. Generally, if you are using a cardboard box to cover the trays, you will need to use 1 tablespoon of sulfur per pound of fruit (weight before drying). If you have constructed a more air-tight sulfuring box from wood, you only need to use 1-1/2 teaspoons of sulfur per pound of fruit ( a stack of four trays holds about 40 pounds of fruit). Sulfur fumes do work, not the burning. Sulfuring is complete when fruit appears bright and glistening, and a small amount of juice appears in the pit cavity. The burning time of sulfur will vary with the ventilation, shape of container and weather conditions.

5. Place the can of sulfur under the box near the lower opening and light the sulfur. Because of the heat resulting from the burning sulfur, space is necessary between the sulfur and the sides of the box, and between the sulfur and the first tray. Do not leave burned matches in the container.

6. Immediately lower the box over the stack, and seal the bottom edges with dirt. Start timing.

7. When sulfur is burning well, close openings in box.

Oven drying is not recommended for sulfured fruits because of the objectionable odor of the sulfur fumes

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