Freezing is a simple, quick way to preserve foods. Vegetables freeze well and retain a fresher flavor if they are stored properly. Texture may be changed somewhat by freezing, but is generally similar to a fresh cooked product. Produce should be scaled before freezing to kill the enzymes that ripen vegetables. Vegetables left unscalded will continue to mature in the freezer causing the texture and flavor to decline.
Many good materials on the specifics of freezing specific vegetables are available through your county extension office or in books such as the Ball Blue Book or the Kerr Canning Guide.
Improperly stored frozen foods may lose quality rapidly. There are several variables that contribute to high frozen food quality. At freezing temperatures, food quality still deteriorates. The lower the temperature, the more slowly the quality deteriorates. At 15º F. food is frozen hard, but is not as solid as that frozen at 0º F. Over a period of time, the food frozen at the lower temperature will maintain better color, texture, flavor, and sometimes nutritive value. Freezing compartments of refrigerators may not be cold enough to hold food for long periods of time. Frequently check the freezer temperature with a thermometer. The freezer should maintain a temperature below 5 degrees.
Foods that are partially thawed but still contain ice crystals can be refrozen. Refreezing may cause a reduction in food quality
Perishable foods that have been completely defrosted should be used immediately or discarded. A fully stocked freezer is more economical to run than a partially full one. Turn over the stock once every six months to reduce the operating costs per pound of food.
Containers for freezing
Packaging should be air tight. Use only moisture and vapor resistant materials such as aluminum foil, polyethylene bags, freezer film wraps, and plastic or metal containers. Shrink film wrap used on meats "breathes" and is not suitable for freezer storage beyond two weeks. Shrink wrap allows foods to dry out and develop freezer burn. Packages must be moisture-vapor proof for best results. Vegetables may be frozen in glass, metal and rigid plastics containers. Plastic bags designed for freezing have thicker plastic than those used for bread and other purposes. The grocery store will have wrapping materials and waxed cartons made for freezing which are moisture vapor resistant. Ordinary waxed papers and paper cartons used for milk, ice cream or similar products are not suitable for long-term storage.
Select vegetables that are fully mature but not over-mature and freeze them as soon as possible after picking. Sort and wash in cool water, and dry thoroughly.
Cut vegetables into serving sized pieces. Before freezing, vegetables should be blanched, cooled quickly and placed in airtight containers.
For boiling water blanching, place the pieces in a strainer and lower them into the boiling water leaving them just until they are scalded. Most vegetables take on a somewhat brighter, translucent appearance as they scald. Do not over-cook. Lift the basket out of the boiling water and dunk quickly into very cold water to cool vegetables quickly. Place the vegetables in air-tight containers and then place them into the freezer.
Vegetables can also be blanched using a microwave oven. Select, wash and prepare the vegetables as previously described for boiling water blanching. Measure a small amount of water, generally about 1/4 cup per pound, into a 2-quart baking dish. Place the vegetables into the dish and heat on high. Be sure that the pieces are spread out and stir them at least once while heating to insure even heating. Time required for adequate blanching will vary according to the vegetable. Vegetables will turn a brighter color as for boiling water scalding. Place the vegetables in air-tight containers and then place them into the freezer.
Most vegetables will retain good quality for at least six months in freezer storage.
Using Frozen Vegetables
Frozen vegetables are best if they are not thawed before cooking. Put the frozen product directly into the boiling water, a microwave, or other cooking method and let it thaw as it cooks. For optimum flavor, do not overcook.