Freezing Basics

Pans and utensils: To freeze vegetables and fruits, you need a colander and a large pot or saucepan that has a wire basket. An accurate freezer thermometer will allow you to regulate your freezer temperature to 0 degrees F or below.

Freezer containers: When freezing foods, use containers and packing materials that are durable, easy to seal, resist cracking at low temperatures, and moisture- and vapor-resistant. Choose the right size of container for your volume of food; too much empty space can lead to oxidation and freezer burn. Remember that foods containing water expand when frozen, so make sure the containers are expandable or leave enough headspace to allow for expansion. The following options are suitable for frozen foods.

• Rigid containers: Use sealable, rigid glass or plastic containers designed for freezing.
• Canning jars: Select canning jars approved for freezing -- this information is clearly noted on the jar packaging. Use only wide-mouth glass jars; jars with necks can crack more easily as contents expand. To allow for food expansion, do not fill jars above the 1-inch line.
• Plastic freezer bags: Use bags designated for freezing, such as resealable bags and vacuum freezer bags. These are made of thicker material than regular plastic bags and are more resistant to moisture and oxygen. In lieu of a vacuum sealer, use your hands to press air from bags before sealing.

• For freezing, select fruits and vegetables at their peak of maturity. Hold produce in the refrigreator if it can't be frozen immediately. Rinse and drain small quantities through several changes of cold water. Lift fruits and vegetables out of the water; do not let them soak. Prepare cleaned produce for freezing as specified in the freezing charts.

• Blanch vegetables (and fruits when directed) by scalding them in boiling water for the specified time. This stops or slow enzymes that can cause loss of flavor and color and toughen the food. Do not blanch in the microwave, because it might not deactivate some enzymes. Timings vary with vegetable type and size. Blanching is a heat-and-cool process. First fill a large pot with water, using 1 gallon of water per 1 pound of prepared food. Heat to boiling. Add prepared food to the boiling water (or place it in a wire basket and lower it into the water); cover. Start timing immediately. Cook over high heat for the time specified in the charts. (Add 1 minute if you live 5,000 feet or higher above sea level.) Near the end of the time, fill your sink or a large container with ice water. When blanching time is complete, use a slotted spoon to remove the food from the boiling water (or lift the wire basket out of the water). Immediately plunge the food into the ice water. Chill for the same amount of time it was boiled; drain.

• Spoon the cooled, drained food into freezer containers or bags leaving the specified headspace. Fruits often are frozen with added sugar or liquid for better texture and flavor. Heavier syrups generally are used with sour fruits, and lighter syrups are recommended for mild fruits. To prepare a syrup, place the recommended amounts of sugar and water in a large saucepan (see pack varieties below). Heat until the sugar dissolves. Skim off foam, if necessary. Use the syrup hot for canned fruits and chilled for frozen fruits. Allow 1/2 to 2/3 cup syrup for each 2 cups fruit.
  • Unsweetened or dry pack: Do not add sugar or liquid to fruit; simply pack in a container. This is best for small whole fruits, such as berries.
  • Water pack: Cover the fruit with water or unsweetened fruit juice. Do no use glass jars. Maintain the recommended headspace.
  • Sugar pack: Place a small amount of fruit in the container and sprinkle lightly with sugar; repeat layering. Cover and let stand about 15 minutes or until juicy; seal.
  • Syrup pack: Cover fruit with a syrup of sugar and water. For a very thin syrup, use 1 cup sugar and 4 cups water to yield about 4 cups syrup. For a thin syrup, use 1-2/3 cups sugar and 4 cups water to yield about 4-1/4 cups syrup. For a medium syrup, use 2-2/3 cups sugar and 4 cups water to yield about 4-2/3 cups syrup. For a heavy syrup, use 4 cups sugar and 4 cups water to yield about 5-3/4 cups syrup.
• If using containers, wipe rims. Seal bags or containers according to manufacturer's directions, pressing out as much air as possible. If necessary, use freezer tape around container lid edges for a tight seal.
• Label each container or bag with its contents, amount, and date. Lay bags flat; add packages to the freezer in batches to make sure food freezes quickly. Leave space between packages so air can circulate around them. When frozen solid, the packages can be placed closer together.

Vegetables are best cooked from a frozen state, without thawing them first. Thaw fruits in their containers either in the refrigerator or in a bowl of cold water. Meats, soups, and casseroles should be thawed in the refrigerator for a day or two, in the microwave oven on defrost, or in a leakproof plastic bag immersed in cold water (change water every 30 minutes). Use frozen fruits and vegetables within 8 to 10 months.