Grow varieties of fruits and vegetables that freeze well. Your county
Extension office can provide information on suitable varieties that grow
well in your locality.
Produce selected for freezing should be of optimum eating quality.
Freezing only preserves the quality of produce as it is at the time of
freezing. It never improves quality.
Fruits to be frozen should be firm and ripe. Underripe fruit may have a
bitter or off-flavor after freezing. Pick berries when ripe and freeze
them as soon after picking as you can. Some fruits--apples, peaches,
pears--may need to ripen further after harvesting. But take care they
don't get too ripe. Frozen fruit prepared from overripe fruit will lack
flavor and have a mushy texture.
Choose young, tender vegetables for freezing. Since vegetables lose
quality quickly after harvest, freeze them as soon as possible for
maximum quality. The sugar in corn, peas, and lima beans is rapidly lost
when held too long before freezing. If you must hold vegetables and ripe
fruits for a short while, refrigeration will help retain the just-picked
freshness better than leaving produce at room temperature.
Wash small quantities of fruit gently in cold water. Do not permit fruit
to stand in water for any length of time since it will become
water-soaked and lose flavor and food value. Drain fruit thoroughly.
Peel fruit and remove pits or seeds. Halve, slice, chop, crush, or puree
fruit as indicated in the instructions for each specific fruit. Some
fruit, especially berries, may be left whole, but remove stems or hulls.
Work with small quantities of fruit at a time, particularly if it is
fruit that darkens rapidly. Two to three quarts is an adequate amount to
handle at one time.
Pack fruit by sirup pack, sugar pack, or unsweetened pack. Most fruit
has better texture and flavor with a sweetened pack. Apples, avocados,
berries, grapes, peaches, persimmons, and plums can all be frozen
satisfactorily without sweetening, but the quality is not quite as good
as freezing in sirup or sugar. An unsweetened pack will give as good a
quality product for gooseberries, currants, cranberries, rhubarb, and
figs as a sweetened pack.
_Sirup pack._ Make a sugar sirup by dissolving sugar in water. A 40%
sirup (3 cups of sugar to 4 cups of water) is recommended for freezing
most fruits. Sirups containing less sugar are sometimes used for
mild-flavored fruits; those with more sugar for very sour fruits. The
type of sirup to use is specified in the directions for freezing each
fruit. Allow ½ to 2/3 cup of sirup for each pint of fruit. Cut fruit
directly into the freezer container, leaving the recommended headspace.
Add sirup to cover fruit.
[Illustration: Slicing strawberries before freezing in a sugar
pack.]
_Sugar pack._ Cut fruit into a large bowl. Sprinkle with sugar. The
amount of sugar to use is specified in freezing directions for each
fruit. Mix gently until juice is drawn from the fruit and all the sugar
is dissolved. Pack fruit and juice into freezer containers.
_Unsweetened pack._ Some fruit may be packed dry, without added liquid
or sugar. Other fruit, particularly if it darkens rapidly, can be
covered with water to which ascorbic acid has been added. Crushed fruit
or sliced fruit that is very juicy can be packed in its own juice
without added liquid.
For all packs except the dry, unsweetened pack, liquid--either sirup,
juice, or water--should completely cover the fruit. This prevents the
top pieces from changing color or losing flavor due to exposure to air
in the headspace.
A small crumpled piece of waxed or parchment paper placed on top of the
fruit helps keep it pressed down in the liquid once the container has
been sealed. The paper should loosely fill the headspace area. Do not
use aluminum foil since acid in the fruit can cause the foil to pit
(form holes), and tiny pieces of foil may drop into the food.
_Anti-darkening._ Many fruits darken during freezing, particularly if
not kept under liquid. Darkening occurs when the fruit is exposed to
air. Since a small amount of air is in the liquid as well as the tissues
of fruit, some darkening can occur even when the fruit is submerged in
liquid. To help retard darkening during freezer storage, add ascorbic
acid (vitamin C) to the fruit during preparation.
Ascorbic acid is available in several forms from drug stores, some
freezer locker plants, and some grocery stores that sell freezing
supplies. Crystalline ascorbic acid is easier to dissolve in liquid than
powder or tablet forms. The amount of ascorbic acid to use is given in
the directions for those fruits where use of ascorbic acid is
beneficial. Ascorbic acid mixtures containing sugar, and sometimes
citric acid, also are available. Follow the manufacturer's directions
for use of these products.
In preparing vegetables, wash a small quantity of the vegetable gently
in several changes of cold water. Lift the vegetable out of the water
each time so all dirt will settle to the bottom of the sink or pan.
Shell, husk, or peel and trim. Some vegetables such as lima beans, corn
on the cob, and asparagus require sorting for size, since blanching
times depend on size of the pieces.
Blanch the vegetable (this is not necessary for green peppers and mature
onions). Most vegetables are blanched by heating them in boiling water.
A blancher consisting of a tall kettle, basket, and cover is convenient
to use and can be purchased at most department or farm supply stores.
However, any large pan which can be fitted with a wire or perforated
metal basket and covered is suitable.
To insure adequate blanching, immerse a basket containing a small amount
of the vegetable (1 pound) into a large amount of boiling water (at
least 1 gallon). Start timing once the vegetable has been immersed and
the kettle is covered. Blanching time will vary with the vegetable and
the size of the pieces, so follow the recommended blanching times for
each vegetable.
Cool the vegetable by immersion in a large quantity of cold or iced
water. Rapid cooling is necessary to stop the food from cooking. Cool
the vegetable for about the same length of time as it was heated. Once
cooled, do not leave the vegetable standing in water, as loss of flavor
and food value can occur. Drain the cooled vegetable thoroughly before
packaging.
Other methods of blanching and cooling are recommended for some
vegetables. For example, mushrooms are heated by sauteing, tomatoes by
simmering in their own juice. These foods are cooled by setting the pan
of food in cold or iced water to speed cooling.