33. PREPARING THE CONTAINERS.--The first step in the cold-pack method
consists in preparing the containers for the food. The jars, rubbers,
and covers, however, do not have to be sterilized as in the open-kettle
method. But it is necessary first to test and cleanse the jars and then
to keep them hot, so that later, when they are filled and ready to be
placed in the water bath, they will not crack by coming in contact with
boiling water. The best way in which to keep the jars hot is to let them
stand in hot water.
[Illustration: FIG. 7]
34. PREPARATION OF THE FOOD.--Attention should next be directed to the
preparation of the food to be canned; that is, clean it and have it
ready for the processes that follow. The fruits or vegetables may be
canned whole or in pieces of any desirable size. What to do with them is
explained later, when the directions for canning the different kinds are
discussed. While the food is undergoing preparation, fill the sterilizer
with hot water and allow it to come to the boiling point.
35. SCALDING AND BLANCHING.--When the food is made ready, the next step
is to scald or blanch it. Scalding is done to loosen the skin of such
food as peaches, plums, and tomatoes, so that they may be peeled
easily. To scald such fruits or vegetables, dip them quickly into
boiling water and allow them to remain there just long enough to loosen
the skin. If they are ripe, the scalding must be done quickly; otherwise
they will become soft. They should never be allowed to remain in the
water after the skin begins to loosen. For scalding fruits and
vegetables a wire basket or a square of cheesecloth may be used in the
manner shown in Figs. 7 and 8.
Blanching is done to reduce the bulk of such foods as spinach and other
greens, to render them partly sterilized, and to improve their flavor.
It consists in dipping the food into boiling water or suspending it over
live steam and allowing it to remain there for a longer period of time
than is necessary for scalding. To blanch food, place it in a wire
basket, a sieve, or a piece of clean cheesecloth and lower it into
boiling water or suspend it above the water in a closely covered vessel.
Allow it to remain there long enough to accomplish the purpose intended.
[Illustration: FIG. 8]
36. COLD DIPPING.--After the food to be canned is scalded or blanched,
it is ready for cold-dipping. Cold-dipping is done partly to improve the
color of the food. It stops the softening process at once, makes the
food more firm and thus easier to handle, and helps to loosen the skin
of foods that have been scalded. It also assists in destroying bacteria
by suddenly shocking the spores after the application of heat.
Cold-dipping, in conjunction with blanching or scalding, replaces the
long process of fractional sterilization, and is what makes the
one-period cold-pack method superior to this other process. To cold-dip
food, simply plunge that which has just been scalded or blanched into
cold water, as in Fig. 9, and then take it out at once.
37. PACKING THE JARS.--Packing the jars immediately follows
cold-dipping, and it is work that should be done as rapidly as possible.
Remove the jars from the hot water as they are needed and fill each with
the cold-dipped fruit or vegetable. Pack the jars in an orderly manner
and as solidly as possible with the aid of a spoon, as in Fig. 10. Just
this little attention to detail not only will help to improve the
appearance of the canned fruit, but will make it possible to put more
food in the jars.
[Illustration: FIG. 9]
When a jar is filled, pour into it whatever liquid is to be used, as in
Fig. 11. As has been stated, hot sirup is added for fruits and boiling
water and salt for vegetables. However, when fruit is to be canned
without sugar, only water is added. With tomatoes and some greens, no
liquid need be used, because they contain a sufficient amount in
themselves.
[Illustration: FIG. 10]
38. PREPARATION FOR THE WATER BATH.--As the jars are filled, they must
be prepared for the water bath. Therefore, proceed to place the rubber
and cover on the jar. Adjust the rubber, as shown in Fig. 12, so that it
will be flat in place. Then put the cover, or lid, on as in Fig. 13, but
do not tighten it. The cover must be loose enough to allow steam to
escape during the boiling in the water bath and thus prevent the jar
from bursting. If the cover screws on, as in the jar at the left, do not
screw it down tight; merely turn it lightly until it stops without
pressure being put upon it. If glass covers that fasten in place with
the aid of a clamp are to be used, as in the jar at the right, simply
push the wire over the cover and allow the clamp at the side to remain
up. Jars of food so prepared are ready for processing.
[Illustration: FIG 11]
[Illustration: FIG. 12]
39. PROCESSING.--The purpose of the water bath is to _process_ the food
contained in the jars before they are thoroughly sealed. Therefore, when
the jars are filled, proceed to place them in the water bath. The water,
which was placed in the sterilizer during the preparation of the food,
should be boiling, and there should be enough to come 2 inches over the
tops of the jars when they are placed in this large vessel. In putting
the jars of food into the sterilizer, place them upright and allow them
to rest on the rack in the bottom. If the filled jars have cooled, they
should be warmed before placing them in the sterilizer by putting them
in hot water. On account of the boiling water, the jars should be
handled with a jar lifter, as in Fig. 14. However, if the sterilizer is
provided with a perforated part like that in Fig. 15, all the jars may
be placed in it and then lowered in place.
[Illustration: FIG. 13]
When the jars are in place, put the tight-fitting cover on the
sterilizer and allow the water to boil and thus cook and sterilize the
food in the jars. The length of time for boiling varies with the kind of
food and is given later with the directions for canning different foods.
The boiling time should be counted from the instant the water in the
sterilizer begins to bubble violently. A good plan to follow, provided
an alarm clock is at hand, it to set it at this time, so that it will go
off when the jars are to be removed from the sterilizer.
[Illustration: FIG. 14]
[Illustration: FIG. 15]
40. SEALING THE JARS.--After processing the food in this manner, the
jars must be completely sealed. Therefore, after the boiling has
continued for the required length of time, remove the jars from the
water with the aid of the jar lifter or the tray and seal them at once
by clamping or screwing the covers, or lids, in place, as in Fig. 16.
Sometimes, the food inside the jars shrinks so much in this process that
the jars are not full when they are ready to be sealed. This is
illustrated in Fig. 17. Such shrinkage is usually the result of
insufficient blanching, or poor packing or both. However, it will not
prevent the food from keeping perfectly. Therefore, the covers of such
jars of food must not be removed and the jars refilled; rather, seal the
jars tight immediately, just as if the food entirely filled them. If, in
sealing jars removed from the water bath, it is found that a rubber has
worked loose, shove it back carefully with the point of a clean knife,
but do not remove the cover.
[Illustration: FIG. 15]
As the jars are sealed, place them on their sides or stand them upside
down, as in Fig. 18, to test for leaks, in a place where a draft will
not strike them and cause them to break. If a leak is found in any jar,
a new rubber and cover must be provided and the food then reprocessed
for a few minutes. This may seem to be a great inconvenience, but it is
the only way in which to be certain that the food will not be wasted
by spoiling.
[Illustration: FIG. 17]
[Illustration: FIG. 18]
[Illustration: FIG. 19]
41. WRAPPING AND LABELING.--When the jars of food have stood long
enough to cool, usually overnight, they are ready for wrapping and
labeling. Wrapping is advisable for practically all foods that are
canned, so as to prevent bleaching, and, of course, labeling is
necessary when canned food is wrapped, so as to enable it to be
distinguished readily when it is in storage. To wrap canned foods,
proceed as in Fig. 19. Use ordinary wrapping paper cut to a size that
will be suitable for the jar, and secure it in place with a rubber band,
as shown, or by pasting the label over the free edge.