A well-fermented sauerkraut should show a normal acidity of approximately +20, or a lactic acid percentage of 1.8 ([p. 16]).
After fermentation is complete, set the sauerkraut in a cool place. If the cabbage is fermented late in the fall, or if it can be stored in a very cool place, it may not be necessary to do more than keep the surface skimmed and protected from insects, etc.; otherwise it will be necessary to resort to one of the following measures to prevent spoilage:
(1) Pour a layer of hot paraffin over the surface, or as much of it as is exposed around the cover. Properly applied to a clean surface, this effectually seals the jar and protects the contents from contamination.
(2) After the fermentation is complete, pack the sauerkraut in glass jars, adding enough of the "kraut" brine, or a weak brine made by adding an ounce of salt to a quart of water, to completely fill the jars. Seal the jars tight, and set them away in a cool place.
The second method is much to be p referred to the first. Sauerkraut properly fermented and stored in this way has kept throughout a season in good condition. Placing the jars before sealing in a water bath and heating until the center of the jar shows a temperature of about 160° F. gives an additional assurance of good-keeping quality of the "kraut."
In the commercial canning of sauerkraut, where conditions and length of storage can not be controlled, heat must always be used.
FERMENTATION AND SALTING OF VEGETABLES OTHER THAN CUCUMBERS AND CABBAGE
There are three methods of preserving vegetables by the use of salt:
FERMENTATION IN AN ADDED BRINE
Experiments have shown that string beans, green tomatoes, beets, chayotes, mango melons, burr gherkins, cauliflower, and corn (on cob) may be well preserved in a 10 per cent brine (40° on the salinometer scale) for several months. Peppers and onions are better preserved in an 80° brine. The brine must be maintained at its original strength by the addition of salt, and the surface of the brine must be kept free from scum. Some of the vegetables listed, notably string beans and green tomatoes, are well adapted to fermentation in a weak brine (5 per cent salt), in which case dill and other spices may be added. The general directions given for dill pickles ([p. 8]) should be followed.