Since antiquity, the art of dehydrating food has saved more than a few civilizations: to the ancient Greeks, Egyptians, and Chinese, drying foods during times of plenty was a lifesaving hedge again times of famine.
Today, it’s an easy way to preserve garden goodness.
Dried food is both convenient and nutritious. In fact, dehydrated foods are more nutritious than their canned counterparts. While the canning process can destroy up to 65 percent of vitamins and minerals, drying food retains most of the vitamins A and C, as well as thiamine and riboflavin. Best of all, there are no chemicals or preservatives necessary for either the drying process or storage.
Another plus, especially if storage space is at a premium, is that dehydrated foods are only one-half to one-twelfth the weight and bulk of the original.
Stored in a cool, dark spot, they should keep anywhere from several months to two years, depending on the food stored.
Draping food over branches or spreading it on wide shallow baskets on the roof is an old widespread tradition still in use around the world. Many other arrangements have been used to support a thin spread of food pieces. Some options that have been used are to thread the pieces on a cord or a stick and hang it over a fire, wood stove or from the rafters. Or one can bundle herbs or strawflowers and suspend them from bushes or a door knob or nails in rooms with good ventilation. Screen doors placed across chairs or sheets hung between clothes lines or possibly on a quilting frame have also been used.
Modern variations are to build special enclosed drying racks or cabinets to expose the food to a flow of dry air heated by electricity, a small gas flame or solar radiation. These are refinements not essential to the basic process but are very helpful, particularly in the humid areas or when the rainy season coincides with the harvest.
If necessary, the drying capacity of the air can be increased by heating it, which lowers the relative humidity. While any source of heat may be used, solar energy is free and usually plentiful. A solar heating panel screened on both ends with air intake on one end and opening to the food at the other is universally used to solar heat air. Hot dry air may be moved over the food by use of natural convection or a solar chimney or a fan run on solar electricity.
Trays need not be bulky and in fact lightweight ones with open screening block less airflow and so are preferable.
Screening may be woven out of local materials or may be commercial screen of non-toxic materials such as nylon and some plastics. Fiberglass screening is not recommended as fibers may become imbedded in sticky food and be eaten. Open weave lightweight nylon material works fairly well. The usual commercial bridal veil is too fragile to last as screening on the trays but may be spread over top to control insects. There should be no toxic dye or insect repellent on material in contact with the food. Coloured cloth should be avoided. Galvanized hardware cloth or aluminium or copper screens are not recommended as potentially toxic salts can migrate into the food.
Wash and dry fruit. Peel if desired and slice thinly. Apples, peaches, and other fruits may darken when exposed to air. This is caused by oxidation which can damage flavor and vitamin content. To prevent oxidation you can dip the fruit slices in a preserving solution.
One solution is a salt water dip which is made by adding six tablespoons of pickling salt to one gallon of water. Soak for two to three minutes, then drain. Pat dry. Another solution is two tablespoons of ascorbic acid powder to one quart of lukewarm water. Soak, drain, and dry as above. Commercial fruit preservatives can also be purchased for this purpose.
Fruits are dry when somewhere between leathery and brittle. Drying times are affected by a number of factors, so experience and common sense are the best guides.
After sun drying fruit it needs to be “equalized.” Remove from trays and place in a bowl inside the house. Several times per day, for one week, stir the fruit pieces. This will allow any moisture from pieces that are not totally dry to be transferred to those which are overly dry.
Another way to equalize dried fruit is to place it in a paper bag after removing from drying trays. Fold over the top of the bag and hang from the clothesline. Shake gently several times a day for two days.
To test if the fruit is sufficiently dried, remove a piece and let it cool. Fruits because of their sugar content may never get beyond a firm bend or leather quality. If they do become brittle, it is OK. They just need a little more soaking or chewing time for full flavor to develop.
Making fruit rolls
Overripe fruit can be used to make fruit rolls and is actually better for this purpose than using fruit which is at its peak.
To prepare fruit for making fruit rolls, rinse then turn the fruit into puree by grinding, putting through a food mill, or mashing with a potato masher. Remove peels, pits, and seeds. Add fruit juice if necessary until it is of a consistency that will pour.
If the fruit is too runny, thicken by cooking over low heat to evaporate water or add a thickener, such as wheat or oat bran.
Sweetening (honey or sugar) or spices can be added if you choose. Begin by adding only one to two spoons of sweetener since many totally ripe fruits need nothing more. If you are making fruit rolls from light colored fruits such as apples or peaches, heat to almost boiling before beginning to dry. This will help prevent browning.
Line a cookie sheet or tray with plastic (don’t use wax paper or aluminium foil) or coat with a non-stick vegetable spray or cooking oil.
Pour the puree in and spread evenly by tilting the tray or sheet back and forth to spread it out. The thinner and more consistent the thickness, the better and quicker it will dry. Around 2 to 3mm thick works well. If it is too thick it may spoil before drying, and if not consistent it will not dry evenly.
When the top side is dry, remove from backing and turn over. Let the other side dry. Cut into squares or strips and roll up. Fruit rolls which are slightly sticky to the touch will keep for about four to six weeks. Rolls which are completely dried will keep longer but may be too brittle to roll.
Store fruit rolls in airtight containers with plastic wrap or paper between them to prevent sticking. Fruit rolls can be eaten as nutritious snacks or dissolved in water and used in any recipe calling for fruit.
Vegetables, like fruits, should be harvested at their peak of flavour. Wash to remove dirt, then prepare for drying by peeling, slicing, etc., as desired.
Controversy abounds over blanching vegetables before drying. Some insist on it, while others feel it is not necessary and successfully preserve without it. To blanch vegetables, steam them over boiling water until they are heated throughout and look translucent when cut with a knife. Remove from steamer and cool immediately with cold running water or plunging into a pan of ice water. Drain, then pat dry with cloth or towel. Spread on drying trays, as with fruits, and dry in the sun.
Most vegetables are dry when they are brittle and will shatter when struck. Slices will snap when bent.
Storing dried food
Often fruit, even when dry, will stick together when stored. A tasty way to help prevent this is by “dusting” before storing. Powdered sugar, spices, or powdered oats can be used as “dust.” Place it in a bag then add fruit and shake to coat the pieces. Dusting fruit leather or placing pieces of paper between the rolls will prevent them from sticking.
Almost anything can be used as a storage container, as long as it has a tight fitting lid. If using a metal lid, place a piece of paper between the food and lid.
Light causes oxidation, so store the dried food in a dark place or put the containers inside paper bags or a cardboard box to block light. Keep in a cool place.
Storing in small batches is wise. In the event one piece is not dry, it will not ruin the entire batch. Label the food before storing and check weekly for signs of mold and weevils for the first several weeks.Dried foods will keep a minimum of six months in storage under the proper conditions.
Using dried foods
Add dried vegetables to soups or stews. The liquid will “re-hydrate” them while cooking. They can also be used in casseroles, sauces, and in nearly any recipe requiring vegetables.
Dried fruit can be eaten as they are or they can be “re-hydrated” by soaking or cooking in juice. The warmer the liquid, the quicker the fruit will soak it up.
Use dried fruits to stew, in baking, jams, sauces, or for syrups.