For many Alaskans, freezing is the preservation method of choice for fresh vegetables grown in their own garden or purchased in quantity from local markets.
In comparison to home canning methods, the processing involved in home freezing foods is considerably simpler and less likely to produce error. Frozen foods are seldom involved in food poisoning. However, food spoilage (such as freezer burn) can occur and frozen foods are subject to losses from mechanical breakdown or power failure.
To maintain top quality, frozen vegetables should be stored at 01/4F or lower. Most refrigerator-freezer combinations and separate freezer units should have no trouble in maintaining this temperature. A freezer thermometer can help you determine the actual temperature of your freezer. These thermometers are relatively inexpensive and generally available at hardware or grocery stores. If your freezer has numbered temperature settings, such as from 1 to 9, check the owner's manual to see what settings are recommended for different uses. Storing frozen foods at temperatures higher than 01/4F increases the rate at which deterioration can take place and can shorten the shelf life of the foods.
Foods for your freezer must have proper packaging materials to protect their flavor, color, moisture content and nutritional value from the dry climate of the freezer. It is best not to freeze vegetables in containers with a capacity over one-half gallon as the foods freeze too slowly to result in a satisfactory product.
Blanching is the first step in preparing vegetables for home freezing. The blanching process involves scalding vegetables in boiling water for a short time. Blanching
stops enzyme actions which can cause loss of flavor, color and texture;
cleanses the surface of dirt and organisms;
brightens the color;
helps retard the loss of vitamins; and
softens the vegetables and makes them easier to pack.
The equipment used for blanching consists of a blancher, which has a blanching basket and cover. Or, you may use a large kettle or pot which has a wire basket that fits down in it and has a lid. (An example is the two-piece pasta pot.) When working with large vegetables, these can be dropped into a large pot of water and removed using a slotted spoon.
Use one gallon water per pound of prepared vegetables. Bring the water to a vigorous boil. Put the vegetables in a blanching basket or wire basket and lower into the boiling water. Place a lid on the blancher. The water should return to boiling within one minute. If this is not the case, you are using too much vegetable for the amount of boiling water. Start counting blanching time as soon as the water returns to a boil. Blanching time is determined by the type of vegetable being processed. Keep heat high for the time given in the directions. A blanching chart is available at the Cooperative Extension Service Juneau office.
As soon as blanching is complete, vegetables should be cooled quickly and thoroughly to stop the cooking process. To cool, plunge the basket of vegetables immediately into a large quantity of cold water, 601/4F or below. Ice cubes may be used to keep the water cold. Cooling vegetables should take the same amount of time as blanching.
Drain vegetables thoroughly after cooling. Extra moisture can cause a loss of quality when vegetables are frozen. Package prepared vegetables in the storage container of your choice. Home frozen vegetables have a storage time of 8-12 months when properly packaged and stored at 01/4F. After this time, the food should still be safe, yet quality may be impacted.
For more information on home food preservation, stop by the Juneau office and pick up a FREE copy of the Cooperative Extension Service publication, Home Freezing of Vegetables (FNH-00264). Or, visit the Extension Web site to download free copies of selected publications: http://www.uaf.edu/ces/publications/fhepubs.html.
Dr. Sonja Koukel is the Juneau District Agent for the Home Economics Programs of the UAF Cooperative Extension Service.