Drying

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Shelf Life

In general, the shelf life of home dried vegetables and fruits stored at 60 F is 4 to 6 months. If the product is stored at 70 F, shelf life will be shortened. See tables on p. 7 and 8 for storage times.

The shelf life of food dried in the home is not as long as the shelf life of commercially freeze-dried products. This is because freeze-dried foods are first frozen at -40 F and then placed in a chamber connected to a vacuum pump. Heat is applied to the frozen food after the air is evacuated from the chamber and the ice sublimes or evaporates directly into vapor. Because the food is frozen and is at a low temperature during drying, there is little nutrient loss and textural damage. Freeze-drying is not practical for home use because elaborate and expensive equipment is necessary.


Drying Instructions

All foods should be prepared by properly sorting, washing, and peeling. If possible, gather vegetables or fruits early in the morning and start the drying process as soon as possible to prevent browning or wilting.

Vegetables

Vegetables must be blanched to inactivate enzymes. The blanching time is counted as soon as the vegetable is immersed in vigorously boiling water. Do not add so much food that the water stops boiling.

The quality of water used to blanch the vegetables can have an effect on the texture of certain vegetables. Very hard water can cause the toughening of vegetables, such as green beans. If you have problems with excessively tough green beans, check into the level of hardness in your water supply.

To Blanch in Boiling Water

To Blanch in Steam

Fruits

Sodium Bisulfite Pretreating fruit with sodium bisulfite will reduce vitamin loss, flavor loss, browning, and deterioration during storage. Sodium sulfite and sodium metabisulfite, available at wine-making shops, may also be used. However, sulfite-sensitive individuals should not use this method.

Prepare a solution of 1 tablespoon sodium bisulfite, or 2 tablespoons sodium sulfite, or 4 tablespoons of sodium metabisulfite to a gallon of water. Soak slices of fruit for 5 minutes and halves of fruit for 15 minutes.

When soaking is complete, remove fruit and rinse lightly under cold tap water. Then place the fruit on the drying trays.

Ascorbic Acid Ascorbic acid (vitamin C) mixed with water is a safe way to prevent fruit browning. However, its protection does not last as long as sulfiting. Ascorbic acid is available in the powdered or tablet form, from drugstores or grocery stores. One teaspoon of powdered ascorbic acid is equal to 3000 mg of ascorbic acid in tablet form. (If you buy 500 mg tablets, this would be six tablets).

Directions for Use Mix 1 teaspoon of powdered ascorbic acid (or 3000 mg of ascorbic acid tablets, crushed) in 2 cups water. Place the fruit in the solution for 3 to 5 minutes. Remove fruit, drain well and place on dryer trays. After this solution is used twice, add more acid.

Fruit Juice Dip A fruit juice that is high in vitamin C can also be used as a pretreatment, though it is not as effective as pure ascorbic acid. Juices high in vitamin C include orange, lemon, pineapple, grape and cranberry. Each juice adds its own color and flavor to the fruit.

Directions for Use Place enough juice to cover fruit in a bowl. Add cut fruit. Soak 3 to 5 minutes, remove fruit, drain well and place on dryer trays. This solution may be used twice, before being replaced.

Fruit Leathers These are chewy candy-like products which are made by pureeing fresh fruits in a blender or food processor. The thick pureed fruit is poured onto a dehydrator tray lined with 4 mil food grade plastic and dried. The puree layer should not be more than -inch thick. Leave a 1 inch border around the puree to allow for spreading during drying. It usually takes 6 to 8 hours to dry fruit leathers.



Using Home-Dried Produce

Dried vegetables need about 2 hours soaking time before cooking. When you soak or rehydrate the vegetables they should plump to nearly the same size they were when fresh. Start with 1 to 2 cups of water for each cup of dried vegetables. If necessary, add more water during the soaking process.

Cook the vegetables in the same water in which they have soaked to save nutrients. Boil or simmer dried vegetables in soups, stews, or other dishes cooked in liquid.

Most dried fruit can be eaten or used in recipes as it is. If you wish to plump or soften the fruit slightly to make it more chewable, you can use one of these methods:

Foods You Should not Dry at Home

Eggs, fish, poultry, and meat (except beef jerky) are not recommended for home drying. Salmonella and Staphylococcus bacteria, which thrive on these foods, can survive and grow at low temperatures used to dry meat and dairy products. These bacteria grow very rapidly in meat and poultry products because all the nutrient needs of these pathogenic or disease producing bacteria are supplied by meats, eggs, and dairy products.

The growth of the pathogenic bacteria will stop when 60 percent ERH is reached, but when water is added to the product, the bacteria will grow again. The poisonous toxin produced by Staphylococcus is not destroyed by cooking the food.

Salmonella and Staphylococcus have caused food poisoning outbreaks in home-dried foods.



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