The Grand White Wines of France and Germany do not require any different treatment from that already described, except that the greatest care is exercised in assorting the grapes and allowing them to arrive at the period of greatest maturity, and, of course, they are made from the choicest varieties.
In describing the condition in which the grapes are when gathered, the French use the word pourris, which is usually translated rotten. But Boireau says that it must not be supposed that the grapes are spoiled (gâtés) because they are pourris; the condition which is sought is a sort of natural dessication effected by the heat of the sun, which evaporates a part of the water of vegetation and concentrates the saccharine matter, as well as the savory and aromatic principle, and bakes the grape, as it were. If the weather remains dry, the grapes remain for a fortnight perfectly ripe without any deterioration of the skin, but little by little it changes from yellow or golden to brown, loses its consistency and rots, or rather cracks and gives way. It is then that dessication commences; the rays of the sun penetrate the thin pellicle and volatilize the water of vegetation. In order to better accomplish this result a portion of the leaves are removed from the vine when the grapes are nearly ripe. Those grapes only are picked which are sufficiently shriveled; if only a part of the cluster is ripe, a few grapes are removed at a picking. The vines are usually gone over in this manner three times. At Barsac and Sauternes the white wines are known by three different names, indicating in their order their strength and sweetness: The first, or sweetest, are called têtes; the second, centres; and the third, queues; or head wines, middle wines, and tail wines. If the must does not indicate more than 12°, 13°, or 14° Baumé, the wine cannot be expected to preserve its sweetness and mellowness in aging. If it is desired to make the sweet head wines, having the inimitable flavor (goút de roti) which they get from the great maturity of the grapes, the density must be allowed to increase till Baumé’s instrument marks 18° to 20°. Wines from must of 16° Baumé will preserve their sweetness for a long time, but as they develop a large amount of alcohol, it is preferable that they be sweeter, and that the must mark 18° to 20°. As these wines do not develop more than 15 to 16 per cent. of alcohol by fermentation, they will not bear transportation through tropical climates with safety, and it is necessary to add spirit enough to raise the strength to 18 per cent. If, however, they are carefully managed, and kept in a cool cellar, they will remain sweet.
Treatment of White Wines.—During the active fermentation they should be left in a moderately warm place of even temperature, and until the foaming has ceased. Then, they may be stored in a cooler place if desirable, or may be left where they are. But then the bungs should be loosely closed with a chip or anything that will allow the escape of gas, and the casks must be filled up every two or three days. When the gas has ceased, they should be bunged tight, and filled up once or twice a week, according to the rapidity of evaporation, until the first racking. (See below.)
To keep Sweet.—If it is desired that the wine should preserve a portion of its sweetness and remain mellow, care should be taken not to disturb it after it has commenced depositing, for thereby the sediment and ferment will be again mingled with the wine and its fermentation rendered more active, all its sugar may be transformed, and the wine become dry. Fermentation may be checked at any period by sulphuring, as is described under the proper head (see [Sulphuring and Unfermented Must]), and so the wines may be made dry or sweet at will; but if the sweet ones contain less than 15 per cent. of alcohol they will ferment. By sulphuring they may be kept sweet from one vintage to another, even if the musts have not a high degree of sugar; but they must be constantly kept under the influence of sulphurous acid and protected from the air. But the frequent sulphuring and racking which they must necessarily undergo gives them an odor and a flavor of sulphur; and if they are not watched they ferment.
The care to be given to white wines after the first racking depends upon their character.
In the Case of Dry Wines, whose sugar has all been transformed, the same attentions are to be bestowed as in the case of new red wines, and the rules laid down are referred to. (See [Red Wine].)
Mellow White Wines, that is, those which retain a portion of their sweetness after the tumultuous fermentation, particularly if they do not carry 15 per cent. of alcohol, require the greatest amount of care in order to preserve their mellowness in aging; for if left to themselves they will again enter into fermentation, and become dry. Such wines should be preserved against all ulterior fermentations, and should be made perfectly bright and freed from ferments, but this should be done with as little fining or filtration as possible, which diminishes their mellowness.
It may be well to note that the less alcohol that mellow wines have, the more susceptible they are to fermentation, and the consequent loss of their mellowness.
Those which have 15 per cent. and have kept their mellowness after the first fermentation, do not lose it as readily as those of a lesser degree. If they have less than 15 per cent. of spirit and are sweet, to retain their sweetness, they must be completely clarified to free them from ferments; and in some cases it is necessary not only to rack them, but at the same time to sulphur them, and fine them with gelatine after adding tannin.
Such wines, not having naturally terminated their fermentation, which was arrested by sulphurous acid, reiterated rackings, the extraction of ferments, and the lowering of the temperature—have a natural tendency to ferment; and the arrested fermentation readily recommences if the wine is left to itself, if vigilance is relaxed, if the temperature increases, or if subjected to the movement of transportation.