Grape-vinegar
A very good vinegar can be made from grapes, although as yet this
outlet for over-production is not largely utilized in America. Grapes
which are unsuitable for raisins, dessert, wine-making or grape-juice
can be used for vinegar-making. Under the most favorable conditions,
grape-vinegar cannot compete in cheapness with vinegar made from
numerous other products and must, therefore, always sell at a high
price. Indeed,
t is doubtful whether a high-grade grape-vinegar can
be manufactured at a less price than good wine. The production of
grape-vinegar requires as much care, but possibly not as much expert
knowledge, as the making of wine. Unlike the latter, however, the
vinegar can be produced on a small scale for domestic purposes by any
one possessing a knowledge of wine-making or vinegar-making.
Grape-vinegar may be manufactured from either white or red grapes,
although that from white grapes is generally preferred. It may be made
either directly from grapes or from wine, the acetifying process being
the same for both. There are, therefore, two distinct stages in the
manufacture of this product. First, there must be alcoholic
fermentation by which the sugar in the grape is changed into alcohol
with the escape of carbonic acid gas. Second, acetic fermentation must
follow the alcoholic fermentation by which the alcohol is changed into
acetic acid.