EFFECT OF TEMPERATURE

Temperature has an important bearing on the success of a lactic fermentation. The bacteria which are essential in the fermentation of vegetable foods are most active at a temperature of approximately 86° F., and as the temperature falls below this point their activity correspondingly diminishes. It is essential, therefore, that the foods be kept as close as possible to 86° F. at the start and during the active stages of a fermentation. This is especially important in the production of sauerkraut, which is often made in the late fall or winter. The fermentation may be greatly retarded or even stopped by too low a temperature.

After the active stages of a fermentation have passed, store the food in a cool place. Low temperatures are always an aid in the preservation of food products.

COLORING AND HARDENING AGENTS

To make what is thought to be a better looking product, it is the practice in some households to "green" pickles by heating them with vinegar in a copper vessel. Experiments have shown that in this treatment copper acetate is formed, and that the pickles take up very appreciable quantities of it. Copper acetate is poisonous.

By a ruling of the Secretary of Agriculture, made July 12, 1912, foods greened with copper salts, all of which are poisonous, will be regarded as adulterated.

Alum is often used for the purpose presumably of making pickles firm. The use of alum in connection with food products is of doubtful expediency, to say the least. If the right methods are followed in pickling, the salt and acids in the brine will give the desired firmness. The use of alum, or any other hardening agent, is unnecessary.

TABLES AND TESTS

Table 1.—Salt percentages, corresponding salinometer readings,
and quantity of salt required to make 6 quarts of brine

Salt in
solution		Salinometer
reading		Salt in 6 quarts
of finished brine
Per centDegreesOunces
1.0642
2.1284¼
3.18126½
4.24168½
5.3 2011
7.422814½
8.483218
9.543620
10.6 4022½
15.9 6035
21.2 8048
26.5 10064