Freezing is a popular, simple way to preserve vegetables. By carefully following directions, you can enjoy top quality, nutritious vegetables year-round.
GENERAL DIRECTIONS FOR FREEZING VEGETABLES
Choose top quality vegetables (produce) at optimum maturity and freshness. Correct freezing techniques will maintain quality but will not improve it.
If vegetables cannot be frozen immediately, refrigerate to retain maximum freshness.
Work with small quantities, enough for only a few containers at a time.
Wash and drain all vegetables before removing shells or skins. Wash small quantities at a time through
several changes of cold water. Do not soak. Lift vegetables out of water to prevent dirt from re-depositing on produce.
Prepare produce according to chart (see SPECIFIC DIRECTIONS FOR FREEZING VEGETABLES).
If desired, blanch vegetables, cool quickly and drain (see BLANCHING and COOLING).
Fill freezer containers. Freezer bags or rigid plastic freezer containers are suitable. Allow enough headspace in rigid containers for food to expand.
Label containers with date, contents and amount of vegetable.
Freeze prepared product immediately. Leave space between packages so they freeze more evenly and quickly. Large ice crystals form in vegetables when too much is placed in the freezer at one time and the freezing process takes too long. Large ice crystals result in texture loss (softening or mushiness) and moisture loss when produce is thawed. When vegetables are frozen quickly, smaller ice crystals are formed, resulting in a better quality product. As a guideline, freeze 2 lb (1 kg) of produce per cubic foot of freezer space per 24 hour period.
The temperature of a freezer should be 0°F (-18°C) or lower.
For best quality and maximum nutrient value, use frozen vegetables within one year.
All vegetables contain enzymes which enable the vegetables to mature. Freezing slows this maturing, or aging, process but does not stop it. Blanching (scalding vegetables in boiling water or steam for a short time) stops the enzyme action that can cause loss of flavour, colour and texture in frozen vegetables. Blanching also cleans the surface of the vegetables, brightens the colour and softens the vegetables making them easier to pack for freezing.
Follow blanching times carefully. Underblanching encourages enzyme activity and is worse than not blanching at all. Overblanching results in loss of flavour, colour and nutrients.
Use a blancher with blanching basket and lid, a pasta pot with fitted strainer and lid or a large pot with a wire basket and lid.
Bring 1 - 2 gallons (4 - 8 L) water to a vigorous boil and leave over high heat throughout the blanching process. A large amount of water is used so the water will resume boiling quickly after the vegetables have been added. Do not add salt unless otherwise specified.
Blanch 2 cups (500 mL) of vegetables for every 1 gallon (4 L) of water. Place prepared vegetables in basket or strainer and lower into vigorously boiling water. Cover pot with lid.
Begin timing immediately (see SPECIFIC DIRECTIONS FOR FREEZING VEGETABLES
blanching times). Blanching water may be reused several times, adding more water as needed.
Some vegetables may be steam blanched.
Use a pot with a tight lid and a basket that holds vegetables above the water in the bottom of the pot.
Bring water to a vigorous boil with the lid on the pot. Leave pot over high heat throughout the
blanching process. Do not add salt unless otherwise specified.
Place only enough vegetables to form a single layer in the basket, so that the steam reaches all surfaces quickly. Place basket in pot over boiling water. Cover pot with lid.
Blanching water may be reused several times, adding more water as needed.
As soon as blanching is complete, the vegetables must be cooled to stop the cooking process.
Plunge basket of vegetables into a large quantity of ice water (water containing ice cubes).
Cool vegetables completely in ice water, about the same amount of time as they were blanched.
Drain vegetables thoroughly after cooling. Pour out onto layers of paper towels or clean tea towels.
Any extra moisture left with the vegetables can cause a loss of quality when vegetables are frozen.
TYPES OF PACKS
After vegetables are blanched, cooled and drained, package immediately in freezer bags or freezer containers.
Remove as much air as possible. Seal tightly.
After vegetables are blanched, cooled and drained, spread in a single layer on a tray and freeze.
When frozen, package vegetables promptly, remove as much air as possible and return to freezer.
Tray-packed vegetables remain loose and can be poured from the container and the package reclosed