Save Garden Bounty By Drying Your Own Vegetables

By Guest Blogger Jennifer Anderson, CSU Cooperative Extension Food Science and Human Nutrition Specialist

Drying vegetables doesn't mean your extra produce will necessary taste like dust. With a bit of know-how and the right tools, everything from beans to tomatoes can be home dried and still maintain much of their nutritional content and flavor.

You'll find details for each vegetable variety listed in the chart at the bottom.

1. Nutritional Values
As with all methods of preservation, drying results in some loss of nutrients. Changes include:
    •  Calorie content: No change, but the calories are concentrated into a smaller mass.
    •  Fiber: No change.
    •  Vitamin A: Fairly well retained under controlled heat methods.
    •  Vitamin C: Mostly destroyed during blanching and drying process.
    •  Thiamine, riboflavin, niacin: Some loss during blanching, but fairly good retention if the water used to rehydrate is also consumed.
    •  Minerals: Some may be lost during rehydration if soaking water is not used. Hadry iron isn't destroyed by drying.

2. Fresh to Dried Yields
Thanks to evaporation, you lose a large amount in volume, occasionally ten times the original.
    •  Lima beans - 7 lbs = 1-1/4 lbs
    •  Snap beans - 6 lbs = 1/2 lbs
    •  Beets - 15 lbs = 1-1/2 lbs
    •  Broccoli - 12 lbs = 1-3/8 lbs
    •  Carrots - 15 lbs = 1-1/4 lbs
    •  Celery - 12 lbs = 3/4 lbs
    •  Corn - 18 lbs = 2-1/2 lbs
    •  Greens - 3 lbs = 1/4 lbs
    •  Onions - 12 lbs = 1-1/2 lbs
    •  Peas - 8 lbs = 3/4 pounds
    •  Pumpkin - 11 lbs = 3/4 lbs
    •  Squash - 10 lbs = 3/4 lbs
    •  Tomatoes - 14 lbs = 1/2 lbs

3. Selecting Vegetables
Select your produce near the peak of their flavor and freshness, usually when they're just about to reach maturity. Sweet corn and green peas, however, should be slightly immature so they keep their sweet flavor before sugars change to starch.

Sort and discard any food with decay, bruises or mold. These defects can affect all the vegetables you're drying.

4. Blanching
Blanching helps slow or stop the enzyme activity that can cause undesirable changes in flavor and texture during storage. Blanching also relaxes tissues so pieces dry faster; helps protect the produces vitamins and color; reduces the time needed to refresh vegetables before cooking; and tends to kill harmful bacteria. 

Water blanching is recommended over steam or microwave blanching because heat is distributed more evenly. You can use plain water or add 1/4 tsp. of citric acid to one quart of water as an anti-darkening and anti-microbial agent. 

Work with small amounts so your water doesn’t stop boiling. Watch closely and precook as follows:

    •  Fill large kettle half full with plain or citric acid water and bring to a boil.
    •  Put no more than one quart of the vegetable pieces in a cheesecloth or other mesh bag and secure ends. (A 36-inch cloth square gathered at the corners works well.)
    •  Drop bag in boiling water, making sure water covers the vegetables.
    •  Shake bag so hot water reaches all pieces.
    •  Start timing as soon as vegetables are in boiling water. Heat for length of time shown in table at end of the post.
    •  Adjust heat to ensure continuous boiling.
    •  Drop bag in very cold water to cool (same amount of time as blanched).
    •  Drain on paper towel or cloth.

5. Preparing Drying Trays
Drying trays can be simple or complex. You can purchase them at many hardware or home-supply stores like Home Depot.

The most important part of your drying tray is that it have good air circulation. If you use galvanized or aluminum screens, line them with cheesecloth or synthetic curtain netting to avoid metal leaching into the food. The liner also will also keep foods from sticking to trays and falling through the screens.

Before and after each use, wash all trays in hot, sudsy water with a stiff brush, then rinse in clean water and air dry. A light coat of fresh vegetable oil or nonstick substance helps protect wood slats and makes cleaning easier.

If trays are used in an oven, they should be 1-1/2 inches smaller in length and width than the oven size to allow for ideal air circulation. When stacking trays, place blocks of wood 2-inches or higher between trays.

6. Oven Drying
You can use either a gas or electric oven to dry vegetables: Both require careful attention to prevent scorching.

The proper temperature and ventilation is vital. To oven dry, preheat at the lowest setting (140 to 150 degrees F), then adjust the thermostat and prop the oven door open to achieve a consistent oven temperature of 140 degrees F, and to allow moist air to escape.

Conventional ovens may not maintain consistent temperatures at low settings. To keep heat at 140 to 150 degrees F, monitor the temperature with a calibrated oven thermometer. Place the oven thermometer directly on the oven rack or tray and check it every two hours while drying.

Arrange pretreated vegetables on drying trays in single or thin layers of 1/2-inch deep (or less) and place in oven. Stack so there is at least 3 inches of clearance at the top and bottom of the oven and 2-1/2 inches between trays. Shift trays, top to bottom and front to back, every half hour. Stir food often if it is 1/2-inch deep or more. Single layers need no stirring.

Food scorches easily toward the end of drying time; therefore, turn the heat off during the final hour and leave the door wide open.

7. Testing for Dryness
Dried vegetables should be hard and brittle to ward off microbes and prevent rot. Test for dryness by taking a small handful and cooling it for a few minutes. When warm, foods will appear soft, moist and pliable but should fulfill the dryness test once they've cooled (found in table at end of this post).

8. Packaging and Storing
Pack small amounts of cooled vegetables in moisture- and vapor-proof freezer containers, boxes or bags. Bags may be heat-sealed or closed with twist ties, string or rubber bands.

Label the containers with the name of the product, date and method of pretreatment and drying. (It's surprising how easily you'll forget the contents of these containers as the winter drags on.) Store in a cool, dry and dark place. Properly stored and dried vegetables keep well for six to 12 months.

Discard food immediately it it takes on a funky odor, flavor or mold.

9. Cooking With Dried Vegetables
One cup of dried vegetables reconstitutes to about two cups. They have a unique texture and flavor and are best used in soups, casseroles, sauces, stuffings and stews. With time and practice, however, you may come to enjoy their texture and find they make good snacks right out of the bag.

To rehydrate and cook leafy or tender vegetables, such as spinach, kale, cabbage, chard or tomatoes, cover with hot water and simmer to desired tenderness. Before cooking, soak any root, stem and seed vegetables as carrots, green beans, peas, corn.

Cover with cold water and soak 30 to 90 minutes; or cover with boiling water and soak 20 to 60 minutes. After soaking, simmer until tender.

Photo by Baha'i Views/Flitzy Phoebie