Drying removes the moisture from the food, to prevent bacteria, molds, yeasts and slows down the enzymes (over ripen) but doesn’t inactivate them. Since, drying removes moisture it makes the end product light weight and smaller. It’s great when used for hiking and camping.
Drying can be done in or outdoors.
For OUTDOOR DRYING can be done by the sun, vine or by making a solar dryer
Sun Drying – Fruits should be the only food that should be dried in the sun. The best time to dry fruits are when it’s hot and breezy out, with a minimum temperature of 85 degrees or above. It all depends on the weather, is how long it takes and if it rains, it will destroy your end product. For equipment, screens to allow air flow around product and bricks on each side to elevate.
Solar Drying – Again fruits are the only food source that should be used. This device can either be purchased or made. There are plans for DIY Solar Dryers. It will have to be moved throughout the day to follow the suns direction.
Vine Drying – Is for drying beans on the vine for storage. Leave beans on vine and let them dry completely until the pods shrivel up and the beans rattle inside. If beans are still moist, they can mold. If they need to be dried more, they can in the sun, oven or dehydrator.
All food that is dried by sun, solar or vine has to be pasteurized to kill any insects or eggs. It can be done by sealing the food in freezer type bags in the freezer (0 or below degrees) for at least 48 hours or in the oven set at 160 degrees, put product in a single layer or shallow pan for 30 minutes.
For INDOOR DRYING it can be done in the oven, electric dehydrator or room drying. Microwaves are only suggested to drying herbs.
Dehydrators – Is an electric appliance with a built-in heating element and a fan to circulate air. Depending on the cost, varies the features.
What to look in a Dehydrator -
Double wall construction of metal or high-grade plastic
Enclosed heating elements, enclosed thermostats that go from 85 to 160 degrees, timer and a dial for regulating temperature
Fan or blower
Four to ten open mesh trays that are easy to clean
UL seal of approval
Choose between a horizontal or vertical airflow, fan on back is the horizontal and vertical is on the bottom. The horizontal advantage is that since airflow is from back to front, reduce flavor mixtures
Oven Drying – Please note Oven Drying is not a safe practice with small children around. Oven drying can take twice as long as dehydrators because it doesn’t have a built-in fan to help move the air. In order to use your oven, temperature has to be able to go down to 140 degrees and when drying leave door propped open 2 to 6 inches to allow airflow. Because the door is left open, make sure you use thermometer to watch the temperature. Trays should be 3 to 4 inches shorter from front to hindmost of oven and racks should be 2 to 3 inches apart.
Room Drying – Differs from sun drying that it takes places indoors in a well-ventilated attic, room or screened in porch. Items are left on vine or stack that are bundled with string or rubber band and suspended until dried. Putting them in brown paper bags, with wholes cut for air ventilation protects them from dust and pollutants. I use this method for all my herbs and flowers for seeds.
Fruit – dry at 140 degrees
Vegetables – dry at 140 degrees
Herbs – dry at 75 to 85 degrees
Meats – dry at 145 to 160 degrees
PREPARING FOOD FOR DEHYDRATION
Blanching – stop enzymes action and retains color. Syrup blanching fruit is similar to candied fruit.
Cooking – pureed fruits and vegetables for fruit leather cooking stops over ripening enzymes.
Antioxidant Dips – prevents browning in fruits.
Soak cut fruit for no more than 10 minutes in ascorbic acid and water
Ascorbic Acid and Water solution
6000 milligram (twelve 500 Milligram) vitamin C crushed tablets to 1 quart of cool water
2 teaspoons crystalline ascorbic acid (food grade) to 1-quart cool water
Fruit Fresh – look at directions
Fruit juice high in vitamin C – can alter flavor
Heat Treatment for Meats (jerky)
After drying meats, put in oven for 10 minutes at 275 degrees to destroy dangerous microorganisms. This process will pasteurize jerky.
Testing for Dryness –
Fruits - pliable, but not sticky or tacky. No visible wetness when squeezed.
Vegetables – leathery or brittle
Herbs – brittle
Fruit and vegetable leathers – chewy, easily peeled from tray
Jerky – chewy and leathery, should crack, but not break went bent. Conditioning – evenly distributes moisture left in food after drying. Improves storage and decreases spoilage done by mold. Fruits, seeds and herbs should be conditioned. Vegetables and Jerky does not since they are dried longer.
How to condition –
Placed cool dried food in a 1 to 2 cups plastic or glass container 2/3 filled, cover. Shake and stir contents daily for 7 to 10 days, checking moisture and spoilage. If moisture is still present, return to dryer. Any seen mold discard.
Pasteurization – ensures destruction of insects and insects eggs n dried food not previously heat treated by blanching or cooking.
How to pasteurize –
Fruit and vegetables – 15 minutes in pre-heated oven at 175 degrees
Jerky – 10 minutes in a pre-heated oven at 275 degrees
Package and Storage -
After food has been dried, conditioned, pasteurized and cool, place in a glass container, food grade plastic freezer container, or a heavy-duty foil covered plastic bag to reduce punctures. Store in a dark, cool dry place. Food stored in 60 degree or lower will keep for one year, stored 80 to 90 degrees will deteriorate after a couple of months. If you would like them to last longer, store in freezer.