56. CLASSIFICATION OF VEGETABLES.--To simplify the directions here given
for the canning of vegetables, this food is divided into four groups,
as follows:
1. _Greens_, which include all wild and cultivated edible greens, such
as beet greens, collards, cress, dandelion, endive, horseradish greens,
kale, mustard greens, spinach, New Zealand spinach, and Swiss chard.
2. _Pod and related vegetables_, which include asparagus, beans, both
string and wax, Brussels sprouts, cabbage, cauliflower, eggplant, okra,
peppers, both green and ripe, summer squash, and vegetable marrow.
3. _Root and tuber vegetables_, which include beets, carrots, kohlrabi,
parsnips, rutabagas, salsify, sweet potatoes, and turnips.
4. _Special vegetables_, which include beans, both Lima and shell, corn,
mushrooms, peas, pumpkin, sauerkraut, squash, succotash and other
vegetable combinations, and tomatoes.
The convenience of this plan will be readily seen when it is understood
that, with the exception of the special vegetables, the same method of
preparation and the time given for the various steps in the canning
process apply to all vegetables of the same class. Thus, if directions
for a vegetable belonging to a certain class are not definitely stated
in the text, it may be taken for granted that this vegetable may be
canned in the manner given for another vegetable of the same class.
57. GENERAL DIRECTIONS.--The canning of vegetables may be most
successfully done by the one-period cold-pack method. Tomatoes,
however, because of the large quantity of acid they contain, may be
canned and kept with little difficulty by the open-kettle method, but
they will be found to keep their shape better if the cold-pack method
is employed.
The time required for cooking any vegetable after it is packed in jars
depends on the kind and the age. Therefore, if a vegetable is hard or
likely to be tough, it may be necessary to increase the time given in
the directions; whereas, if it is young and tender or very ripe, as in
the case of tomatoes, the time for cooking may perhaps have to be
decreased. Because, in altitudes higher than sea level, the boiling
point of water is lower than 212 degrees Fahrenheit, the length of time
for boiling foods in the water bath must be increased after an altitude
of 500 feet is reached. Therefore, for every additional 500 feet over
the first 500 feet, 10 per cent. should be added to the time given for
the boiling in water. In case a pressure cooker is used, however, this
is not necessary.
The canning directions here given are for 1-quart jars. If pint jars are
to be used, decrease the salt proportionately; also, decrease the time
for cooking in each case one-fifth of the time, or 20 per cent. If
2-quart jars are to be used, double the amount of salt and add to the
length of time for cooking one-fifth, or 20 per cent. For instance, if a
1-quart jar of food requires 90 minutes, a pint jar of the same food
would require 72 minutes and a 2-quart jar, 108 minutes.