As soon as the food is cool, put it promptly into freezer containers of
moisture-vapor-proof or moisture-vapor-resistant packaging material.
Pack the food tightly into the container to reduce the amount of air in
the package.
In quart containers, the food may be separated into two or three layers
by a double thickness of water-resistant material such as cellophane
between the layers. This makes it possible to separate the frozen block
of food easily to shorten the reheating time.
Choose a size of container that holds only enough for one meal for your
family. Quart containers hold 4 to 6 servings; pints, 2 to 3. Use only
containers with wide top openings so the food does not have to be thawed
completely to remove it from the container.
Containers and materials. Many combination main dishes are semiliquid in
consistency and are best packaged in rigid containers made of
moisture-vapor-proof materials such as aluminum, glass, pottery,
plastic, plain or enameled tin, or moisture-vapor-resistant material
such as heavily waxed cardboard.
Some prepared foods, like meat pies and casserole dishes, may be frozen
in the containers in which they were baked, ready for reheating at time
of using.
Bags of suitable material can be used for semiliquid foods but are less
convenient than rigid containers. They are well adapted to less moist
foods. Sheets of freezer packaging materials are used for wrapping foods
that hold their shape.
Bags and sheets are made of moisture-vapor-resistant cellophane, heavy
aluminum foil, pliofilm, polyethylene, or laminated papers consisting of
combinations of paper, metal foil, glassine, cellophane, or other
materials.
Unwaxed folding cardboard cartons are often used to hold foods packaged
in bags or sheets for protection against tearing and for easy stacking
in the freezer. Sheets of packaging material may be used as outer wraps
for unwaxed cardboard cartons containing unwrapped foods. The sheets are
sealed with freezer tape, or with a warm iron if they are heat-sealing
on both sides.
Ordinary waxed papers, household aluminum foil, and cartons designed for
cottage cheese and ice cream are not sufficiently
moisture-vapor-resistant to be suitable for packaging foods to be frozen
and held more than a few days.
Head space. Since liquid expands as it freezes, allow ample head space
when packing liquid and semiliquid foods. Most freezer containers have a
mark or line to show how much head space to leave. For a tall, straight
or slightly flared container and for bags, ½ inch is generally
recommended for pints and 1 inch for quarts. For low, broad containers
less head space is needed, about ¼ inch for pints and ½ inch for quarts.
To assure a good closure, keep sealing edges free from moisture or food.
When packaging foods with freezer sheet material, wrap them as tightly
as possible.
Sealing. Seal rigid freezer containers by adjusting the lids as required
for the type of package used. Casseroles made of ovenproof material can
be covered and then sealed with freezer tape or wrapped as needed.
Bags can be sealed by twisting and folding back the top and securing
with a string or with a paper-covered metal strip or rubber band that
may come with the bag. Some bags and sheets may be heat-sealed with a
warm household iron or one of the special sealing irons available on the
market. Others may be sealed with freezer tape.