This disease develops more or less rapidly, according to the alcoholic strength of the wine and the temperature of the place where it is kept. Those common, weak wines, which have only from 7 to 8½ per cent. of alcohol, are the first attacked; on them flowers are developed in three or four days. Stronger wines, which contain from 10 to 11 per cent. of spirit, resist twice as long as the weaker ones. Fine wines of an equal strength resist better than the common kinds; and wines which contain more than 15 per cent. are not affected. During summer they are much sooner affected.
Machard is of the opinion that this flavor is due to the commencement of disorganization of the ferments remaining in the wine, which, as they begin to putrify, give off ammoniacal emanations. Maumené says that it is due to the loss of carbonic acid.
To Prevent Flatness, all agree that wines should be protected from the air; for this purpose they should be kept in casks constantly full, or in well corked bottles lying in a horizontal position. When it is necessary to leave ullage in the cask, a sulphur match must be burned, and the cask tightly bunged. (See [General Treatment], [Wine in Bottles], [Sulphuring], etc.)
In frequently drawing from the cask, the deterioration is retarded by taking care to admit the least possible amount of air, just enough to let the wine run, but the evil cannot be entirely prevented in this way; and by frequent sulphuring the wine will acquire a disagreeable sulphur flavor; therefore, ullage should never be left when it is possible to avoid it.
Treatment.—When the wines show flowers, but have not yet become flat, as in the case of new wines which have been neglected, and have not been filled up for a week or more, and are only affected at the surface, by filling up, the flowers may be caused to flow out at the bung. The cask must then be well bunged. It must afterwards be kept well filled, for besides the flat flavor that the flowers may give the wine, they will render it turbid on account of the acid ferments introduced, and cause it to become pricked in the end.
Wine badly flowered, and which has acquired a decided flavor of flatness, without being actually sour, should be filled up, and the flowers should be allowed to pass out of the bung; it should then be racked into a well sulphured cask, which must be completely filled. The flowers must not be allowed to become mixed with the wine. After racking, two or three quarts of old brandy to each 100 gallons should be added, or a few gallons of firm, full-bodied wine, as near as possible of the same natural flavor. It should then be well fined, using in preference the whites of eggs (one dozen for 100 gallons, and a handful of salt dissolved in a little water), and then it must be racked again as soon as clear.
The object of this treatment is to extract from the wine by racking the mould which causes the bad taste; to replace by fortifying, the alcohol lost by evaporation; and finally, by fining, to remove in the lees the acid ferments, which have developed in the form of flowers.
Yet those wines which have become badly affected through negligence are never completely restored, and if they are fine, delicate wines, they lose a large part of their value. Therefore, great care should be taken to prevent this disease, which in the end produces acidity, for, often, neglected wines are at the same time flat and pricked.
Some authors recommend that such a wine should be again mixed with a good, sound, fresh pomace, which has not been long in the vat, and allowed to ferment a second time; this is called passing it over the marc. Of course, this can only be done in the wine making season, and cannot be resorted to by those who do not make wine themselves, or who are at a distance from a wine maker.
When all else fails, they recommend that several large pieces of dry, fresh charcoal be suspended in the wine, attached to cords to draw them out by, Maigne says, for forty-eight hours, and Machard says, one or two weeks, renewing the charcoal from time to time till the taste is removed.