Degeneration and Putridity.—Wine may be kept and improved in bottles, if properly treated, as long as its constituent principles remain soluble and in combination; but with the lapse of time, varying with different kinds, it begins to lose quality. This degeneration, says the author last quoted, announces itself a long time in advance, in the grand wines, by a loss of their unctuosity, of their fruity flavor, and by a bitter and sometimes acrid taste; and if they are kept for several years more, the fragrance of the bouquet is lost, and they contract a rancio or tawny flavor, which masks their natural flavor; they rapidly lose color, and form a deposit much more considerable than in the earlier years of their sojourn in bottles; and finally, when their degeneracy is advanced, they give off a slightly putrid odor.
As soon as high priced wines have attained their entire development in bottles, in order to prevent their decline, they should be carefully decanted into bottles with ground glass stoppers, previously rinsed with wine of the same kind.
Loss of color, joined with an abundant deposit, which is a sure sign of degeneration in the wines of the Gironde, do not mean the same in all other kinds. For instance, the red wines of Spain (and we may add, Portugal), and the sweet wines of Roussillon, which have a very dark color when young, almost entirely lose it after three or four years in bottle; they become tawny, without degenerating; but, quite to the contrary, their quality is improved.
It is observed, however, that in wines of these latter classes, whose alcoholic strength exceeds 15 per cent., the deposit is not so great, compared with the amount of coloring matter precipitated, as in wines of the first mentioned growth, and that the coloring matter adheres to the sides of the bottle, instead of falling to the bottom. Some of our California wines deposit a good deal of color in the bottle, even when fined. Probably a double fining would be advantageous in many cases.
As alcohol and tannin are the preservative principles of wines, those last longest which are best provided with them.
The cause of the degeneration of wine is the decomposition of its constituent parts, which thereby become insoluble, and are precipitated. The loss of tannin, which in time is transformed into gallic acid, takes from feeble wines their best conservator, and causes precipitation of the coloring matter. And it is observed in practice that wines which contain a great quantity of tannin last longer than those of the same alcoholic strength having less tannin.
Decantation consists in drawing a wine from the bottle containing it, so as to leave the sediment behind. It should be done without exposing the wine to the air.
The bottles should be brought from the cellar without changing their position, for if the deposit is disturbed, and the wine becomes cloudy, the bottles must rest till it has settled again. For this purpose they are laid in a basket, or other suitable receptacle, where they are inclined just enough so that the wine will not run out when the cork is removed ([fig. 40]). The cork must be drawn without disturbing the sediment, by using a corkscrew, which by means of a screw or lever, gradually removes it, and without a shock ([fig. 41]). The wine is slowly run into another clean bottle previously rinsed with the same kind of wine. If the wine is in its decline, rinse the bottles with old brandy.
Fig. 40.
