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GIGGLE WATER
278. TO DETERMINE THE NATURE OF
ACIDITY IN WINE
If wine has undergone the acetous fermentation, then
convert it at once into vinegar by one of the usual modes.
But if its acidity proceeds from an excess of tartaric acid,
this defect may be remedied by shaking the wine with a
concentrated solution of neutral tartrate of potassa, which,
with the surplus of tartaric acid, will form bitartrate of
potassa, and precipitate as such. To discover the nature of
the acidity, neutralize an ounce or so of the wine with
some carbonate of soda, then add a small quantity of sul
phuric acid, and boil up; if acetic acid or vinegar be pres
ent, it will be perceptible by its odor.
279. PARENT'S METHOD OF PRESERVING
WINE
This consists in the addition of a small quantity of
tannin or tannic acid to the wine, which perhaps acts in
a similar way, by destroying the vitality of the spores of
the fungus, since a microscopic examination of wine
known to contain these germs, within a few weeks after
being treated with the tannin, has failed to detect the
slightest trace. Indeed, wine which has already begun to
change, and become turbid, can be restored to its primitive
clearness, and with a great improvement in its taste. Care
must be taken, however, to use only tannin which has been
prepared from the constituents of the grape, since the