Cask Flavor, or Barrel Flavor—Causes.—This, says Mr. Boireau, should not be confounded with the wood flavor derived from oak wood, and which wines habitually contract when stored in new casks, and which comes from aromatic principles contained in the oak. This barrel flavor is a bad taste, which appears to come from an essence of a disagreeable taste and smell, and which is the result of a special decay of the wood of the cask. This vice is rare. It is impossible for the cooper to prevent it, for he cannot recognize the staves so affected, so as to reject them. For those pieces of wood which have a disagreeable smell when worked, or show reddish veins, blotched with white, often produce casks which give no bad taste to the wine, while other staves selected with the utmost care, sometimes produce that effect, and even in the latter case it is impossible to point out the staves which cause the trouble. When such a cask is found, the only way is to draw off the wine, and not use the cask a second time.
The Treatment for wines which have contracted a bad taste of the cask, is to rack them into a sweet cask, previously sulphured, to remove them from contact with the wood which has caused the trouble. The bad taste may be lessened by mixing in the wine a quart or two of sweet oil, and thoroughly stirring it for five minutes, first removing a few quarts of wine from the cask to permit of the agitation. The oil is removed from the surface by means of a taster, or pipette, as the cask is filled up. The wine should then be thoroughly fined, either with whites of eggs or gelatine, according to its nature, and racked at the end of one or two weeks.
The reason for the treatment is that the fixed oil takes up the volatile essential oil, which apparently produces the bad flavor. The olive oil used contracts a decided flavor of the cask.
This treatment diminishes the cask flavor, but rarely entirely removes it.
Maigne says that to succeed well by this process, the oil should be frequently mixed with the wine, by stirring it often for two or three minutes at a time, during a period of eight days. It is also necessary that the oil be fresh, inodorous, and of good quality, and of the last crop.
The same author gives another process, that of mixing with the wine sufficient sugar or must to set up active fermentation. After the fermentation has ceased, fine and rack.
This author also mentions other methods of treatment, but as olive oil is the remedy more generally used, it is not worth while to give them at length; suffice it to say, that the substances recommended are, a roasted carrot suspended in the wine for a week; a couple of pounds of roasted wheat suspended in the wine for six or eight hours in a small sack; the use of roasted walnuts, as mentioned for sourness; and two or three ounces of bruised peach pits, soaked two weeks in the wine.
Mouldy Flavor—Bad Taste Produced by Foreign Matters.—Wine contracts a musty or mouldy flavor by its sojourn in casks which have become mouldy inside, on account of negligence and want of proper care, as by leaving them empty without sulphuring and bunging. (See [Casks].) The mould in empty casks is whitish, and consists of microscopic fungi, which are developed under the influence of humidity and darkness. The bad flavor appears to be due to the presence of an essential oil of a disagreeable taste and smell.
Prevention and Treatment.—It is prevented by carefully examining the casks before filling them, and by avoiding the use of those which have a mouldy smell. Wines affected by this flavor require the same treatment as those affected with cask flavor.
Maigne says that this taste may also be corrected by applying a loaf of warm bread to the open bung, or by suspending in the wine a half-baked loaf of milk bread. The operation should be repeated in three or four days.