Material selected for packaging fruits and vegetables for freezing must
be moisture-vapor-proof or moisture-vapor-resistant to keep the food
from drying out and from absorbing odors from other foods in the
freezer. Loss of moisture from the food causes small white areas called
"freezer burn" to develop. These areas are not harmful, but if extensive
they can cause the food to become tough and lose flavor.
Suitable packaging materials include rigid plastic food containers,
plastic freezer bags, heavy aluminum foil, freezer paper or plastic
film, glass freezer jars, and waxed freezer cartons. Collapsible,
cardboard freezer boxes are frequently used as an outer covering for
plastic bags to protect them against tearing.
Select packaging materials suiting the shape, size, and consistency of
the food. Rigid containers are suited for freezing all foods, but are
especially good for fruit packed in liquid. Non-rigid containers are
best for fruits and vegetables packed without liquid. Paper, plastic, or
foil wraps are ideal for freezing bulky vegetables such as broccoli,
corn on the cob, and asparagus.
Rigid containers with straight sides and flat bottoms and tops stack
well in the freezer. They take up less freezer space than rounded
containers, containers with flared sides, and bulky, wrapped packages or
plastic bags without protective outer cartons. Containers with straight
sides or those that are flared, having wider tops than bottoms, are
preferred for easy removal of the food before thawing. If the opening is
narrower than the body of the container, the food will have to be
partially thawed so you can get it out of the container.
Freezer containers and bags are available in a variety of sizes. Do not
use those with more than ½-gallon capacity for freezing fruits and
vegetables since the food will freeze too slowly, causing poor quality
food.
Choose a container that will hold enough food for one meal for your
family. You may wish to put up a few smaller packages for use when some
family members are not home or to go with your family-size packages when
guests are present for meals.
Pack foods tightly into containers. Since most foods expand during
freezing, leave headspace between the packed food and closure.
For fruits that are in liquid, pureed, or crushed and packed in
containers with wide openings, leave ½-inch headspace for pints, 1-inch
headspace for quarts. If containers with narrow openings are used, leave
¾-inch headspace for pints, 1½-inch headspace for quarts.
For fruits and vegetables packed without liquid, leave ½-inch headspace
for all types of containers. Vegetables that pack loosely, such as
asparagus and broccoli, require no headspace.
Any container for freezer use must be capable of a tight seal. Rigid
containers should have an airtight-fitting lid.
Press out all air from the unfilled parts of plastic bags. Immediately
twist the top of each bag and securely tie it with a paper- or
plastic-covered wire twist strip, rubber band, or string to prevent
return of air to the bag.
Some bags may be heat-sealed with special equipment available on the
market. Follow the manufacturer's directions.
Edges and ends of paper, foil, or plastic wraps should be folded over
several times so the wrap lies directly on top of the food and all air
has been pressed out of the package. Seal the ends with freezer tape to
hold them securely in place.