1928 Giggle Water by Charles S Warnock

136 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