Made from both Red and White Grapes.—As the color of grapes resides entirely in the skins, with the exception of a few varieties such as the Tienturiers and the American variety Lenoir, which have colored juice, with these exceptions, white wine may be made from both white and colored grapes.

Differences between Red and White Wine.—Instead of putting the pomace into fermenting vats, it is taken immediately to the press, and the juice is fermented by itself, free from stems, skins, and seeds, and is therefore not only free from the coloring matter contained in the skins, but also from the numerous matters that are contained in red wine, extracted from the pomace during fermentation. It is true that white wine may be made from white grapes by the process that is employed in making red wine from colored grapes, but then it ceases to be what is commonly called white wine, and possesses all the characteristics of red wine except its color, which of itself has little effect upon the wine, except to change its appearance; for when white wine has been colored by the addition of a small quantity of very dark wine, it remains white wine still in all its other characteristics, and the difference is readily detected by experts.

Hygienic effects of Red and of White Wine.—Dr. Guyot says that white wines generally are diffusible stimulants of the nervous system; if they are light, they act rapidly upon the human organism, and excite all its functions. But they escape as readily by the skin and excretory organs, and their effect is of short duration. Red wines, on the other hand, are tonic and persistent stimulants of the nerves, muscles, and digestive organs; their action is slower and more prolonged; they do not increase perspiration or the excretions, and their action generally is astringent, persistent, and concentrated.

Process of Making.—As the must comes from the press it is either immediately run into casks, or is first put into a vat to settle. In the latter case it is allowed to stand in the settling vat from twelve to twenty-four hours, and a large portion of the yeasty parts settle to the bottom, a thick scum rises to the surface, and the must becomes partially cleared. The scum is then skimmed from the top, and the liquid is drawn off into casks, leaving the heavy lees. By this means a great part of the fermentive matter is immediately removed, and the wine does not ferment as thoroughly nor as rapidly as it otherwise would, and retains a portion of its sugar and its sweetness longer. In the Champagne districts the musts for sparkling wines are thus treated. If the weather is very warm, it may not be practicable to do this, because fermentation will set in before the must has time to settle. If, however, it is desired to make a dry wine, the must is not put into a settling vat, but is run from the press directly into the casks.

The Barrels in which white wine is fermented and stored are generally of small size, of a capacity of from 30 to 150 gallons, or say 50 or 60 gallons on an average, and it is considered in France that it preserves its good qualities in casks of moderate size better than in large ones. It is to be understood, however, that it is considered advisable in most parts of France that white wine should retain a portion of its sweetness and be mellow rather than dry; but if it is desirable to make a dry wine, larger casks may be used for fermenting and storing. (But see Summary of Rules, below, and Casks.)

Filling the Barrels during Fermentation.—A question upon which there is some difference of opinion, is whether the casks should be immediately filled to their full capacity and kept filled up during the first fermentation, so that the scum and foam will be thrown out of the bung, or whether a vacant space shall be left in each barrel, so that all the matter thrown up by the fermentation shall remain. The objections to allowing the wine to boil over are that much good wine is thereby lost, and the outside of the barrels and the floor of the fermenting house or cellar becomes foul. When the active fermentation ceases, whatever has been thrown up in the form of a dirty scum will settle to the bottom with the rest of the lees, and is no more injurious than the latter. If, however, the foam is allowed to run over by keeping the barrels full, a portion of the yeasty parts will be thrown out, fermentation will not go on as tumultuously nor be as complete, and the wine will longer retain a portion of its sweetness. So that the practice in this behalf, as in most others where there is a diversity of practices in making white wine, depends upon whether it is desired to make a very dry wine, or one that retains a portion of its sugar. But in the Champagne districts, although they allow the marc to settle, they do not allow it to run over in fermenting.

Pressing and Filling.—The pomace is pressed in the same manner as the marc of red wine, in two or three different pressings. The usual practice is to fill the barrels with an equal amount of must from each pressing, so that the contents of all shall be uniform in quality. If it is known beforehand how much wine can be made from a given quantity of grapes, the requisite number of barrels will be provided for each lot, and the must of each pressing will be equally distributed in all. (See General Chapter.)

Different kinds of White Wine.—Boireau divides white wines into three classes: dry, mellow, and sweet, whose characteristics depend essentially upon the density of their musts.

In Dry White Wines fermentation is complete, and all the sugar that is appreciable by the taste or the hydrometer, except the small amount changed into other substances, is transformed into alcohol and carbonic acid. The grapes are gathered as soon as ripe, and are not allowed to shrivel. The density of the must rarely exceeds 13° Baumé.

Mellow White Wines are those which preserve a small quantity of sugar after the tumultuous fermentation has ceased, and which gives them mellowness and unctuosity. To produce these wines, it is necessary to increase the density of the must, which is accomplished in the Gironde by leaving the grapes upon the vines until they shrivel and turn brown (white grapes are used), and they are gathered by several successive pickings. The density of the must is from 12° to 15° Baumé. These wines occupy the place between dry wines and sweet wines.

White Sweet Wines (vins de liqueur) are those which preserve a considerable portion of their sugar, which renders them very sweet. And in order that they may retain their sweetness in aging, the must should mark 15° to 20° Baumé.

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.

On the contrary, in those which have acquired the largest amount of alcohol possible by fermentation (between 15 and 16 per cent.), no new spirit is formed at the expense of the sugar, except in case of loss of strength by evaporation or other enfeebling cause.

Summary of Rules for the treatment of mellow white wines, according to Boireau:

Racking.—When they remain calm after the insensible fermentation is terminated, whether they are old or young, they should be racked three times each year; first, at the sprouting of the vine in the spring, in March, before the equinox; secondly, at the flowering of the vine in June, before the summer solstice; and thirdly, at the ripening of the grape in September, before the autumnal equinox. (See Racking.)