NATURAL DEFECTS.
Earthy Flavor—Its Causes.—It is a natural defect in the wine, and consists of a bad taste by which the pulp and the skins of the grapes are affected before fermentation. It occurs in wine made from grapes grown on low, wet, swampy land, and on land too heavily manured, or fertilized with substances which communicate a bad flavor. He says that this must not be confounded with the natural flavor and bouquet of the wine. Contrary to the opinion of those œnologues who attribute this defective flavor to the presence of essential oils, he believes that there is a sensible difference between the natural flavor (séve) and the earthy flavor. In fact, the flavor and bouquet of wines made from grapes of the same variety, but grown in different vineyards, present considerable differences, which are due to the different natures of the soils, to the different processes in wine making, to climate, exposure, age of the wine, etc. On the other hand, the taste and odor produced by the natural flavor and bouquet are not entirely developed till the wine is old, and the clearing is complete; while the bad taste transmitted from the soil through the sap, instead of increasing with age, diminishes, and often finally disappears. The reason is that this taste being communicated principally by the coloring matters of the skins, diminishes with the deposit of these matters, according as the wine becomes clear. It follows that certain wines may have a good flavor, and even acquire a bouquet in aging, which while young had a disagreeable earthy flavor.
He instances the wines of several crops, treated by him, having a fine color, mellowness, and 10 per cent. of alcohol, which in their early years had an earthy flavor so pronounced that it might almost have been taken for a mouldy taste. This taste diminished gradually, with proper care, and finally disappeared toward the third year; the natural flavor then developed itself, and the wines acquired an agreeable bouquet in bottles.
Grapes from young vines planted in moist land, have an earthy flavor more pronounced than those from older vines, grown in the same situations, and this flavor is generally more developed in the heavy-yielding common varieties than in the fine kinds.
How Prevented.—This flavor may be sometimes diminished or destroyed by draining the soil of the vineyard, aerating the vines when too crowded, and by avoiding the planting of trees in the vineyard. If it comes from too much manure, less should be used, and less wood left on the vines.
Great care should be taken to draw such wines from the fermenting vat, as soon as the active fermentation is finished, for a long sojourn in the tank with the stems and skins aggravates the defect.
The Treatment of wines so affected differs according to their origin, their nature, and their promise of the future; but the condition necessary in all cases is to promptly obtain their defecation or clarification, and never to allow them to remain on the lees. They should therefore be drawn off as soon as clear, and frequently racked to prevent the formation of voluminous deposits.
Red wines, which in spite of this defect, have a future, and may acquire quality with age, should be racked at the beginning of winter, again in the beginning of March, and after the second racking should be fined with the whites of 12 eggs to 100 gallons of wine; they are then racked again two weeks after fining.
Common red wines, without a future, dull and poor in color, and weak in spirit, are treated in the same manner, but before fining, a little more than a quart of alcohol of 60 to 90 per cent. is added to facilitate the coagulation of the albumen.
In treating wines which are firm, full-bodied, and charged with color, after the two rackings, an excellent result is obtained by an energetic fining with about three ounces of gelatine.
Earthy white wines should be racked after completing their fermentation, and after the addition of about an ounce of tannin dissolved in alcohol, or the equivalent of tannified white wine. After racking, they should be fined with about three ounces of gelatine.
These rackings and finings precipitate the insoluble matters, and part of the coloring matter, which is strongly impregnated with the earthy taste, and the result is a sensible diminution of the flavor. When not very pronounced, it is removed little by little at each racking. But if it is very marked, the wine after the first racking should have a little less than a quart of olive oil thoroughly stirred into it. After a thorough agitation, the oil should be removed by filling the cask. The oil removes with it a portion of those matters in the wine which cause the bad flavor. The wine is afterwards fined as above.
Some writers recommend that wine having an earthy flavor should be mixed with wine of a better taste, as the best method of correcting the defect; but from what has been said in the preceding part of this chapter, it would seem to be an unsafe practice.
The Wild Taste and Grassy Flavor are due to the same causes, and are removed in the same way.
Greenness—Its Causes.—This is due to the presence of tartaric acid, which it contains in excess. It gives a sour, austere taste to the wine, which also contains malic acid, but in a less quantity. When tasted, it produces the disagreeable sensation of unripe fruit to the palate, sets the teeth on edge, and contracts the nervous expansions of the mouth.
Greenness, as the term imports, is caused by want of maturity of the grapes. We all know that acids abound in unripe fruit, and it is only at the time of maturity, and under the influence of the heat of the sun, that they disappear and are changed into glucose or grape sugar.
A green wine, then, is an imperfect wine, which, besides this defect, generally lacks alcohol, body, mellowness, firmness, bouquet, and color, because the incompletely matured grapes contain much tartaric and malic acid, and but little grape sugar and other mucilaginous matter, and because the matters destined to give color to the skins, as well as the aromatic principles, are not completely elaborated.
The only way to Prevent this Defect is to resort to means necessary to increase the maturity of the grape, or to add sugar to the must, neither of which will scarcely ever be found necessary in California, where the defect is not likely to exist, if the grapes are not picked too green.
Treatment.—Where the sourness is not insupportable, the wine may be ameliorated by adding a quart or two of old brandy for each 100 gallons.
The wine as it comes from the vat contains much more free tartaric acid than it contains after the insensible fermentation in the cask, because it combines with the tartrate of potash in the wine and forms the bitartrate of potash, or cream of tartar, which is deposited with the lees, or attaches itself to the sides of the cask. It follows that the wine will be less green after insensible fermentation, at the first racking, than when it was new; but if the greenness is excessive after the insensible fermentation, the wine still contains much free acid. The excess of acid may be neutralized in wines which are very green by adding the proper amount of tartrate of potash, which combines with a part of the tartaric acid to form the bitartrate, which after a few days falls to the bottom, or adheres to the cask. The dose varies from 10 to 24 ounces per 100 gallons of wine. Five or six gallons of wine are drawn out of the cask, and the tartrate of potash is thrown in by the handful, stirring the while as in the case of fining. This treatment does not always succeed; hence, the necessity of preventing the defect when possible.
When the greenness is not very marked, the wine may also be mixed with an older wine, which contains but little acid and plenty of spirit.
Lime and other alkaline substances will surely neutralize the acid, but they injure the wine and render it unhealthy, and should never be used.
Machard lays great stress upon the addition of brandy to such wines, because, he says, the alcohol will precipitate the excess of acids, and will also combine with them to form ethers which give a delicate, balsamic odor to the wine, which is most agreeable. (See [Ethers], [Bouquet].)
Roughness is due to the astringency given to the wine by the tannin when in excess. Tannin is useful for the preservation and the clarification of wines, and those which contain much, with an equal amount of alcohol, keep much longer than those which contain less, and undergo transportation better, and are considered more healthful.
Roughness is Not a Fault, it is rather an excess of good quality, if the rough wines have no after-taste of the stems, bitterness, earthy flavor, acrity, and possess a high degree of spirit, a fruity flavor, and a good color. Such wines are precious for fortifying, and to assist in aging those which are too feeble to keep a long time without degenerating. When kept without cutting, they last a long time, and end well. But they are long in developing.
The Roughness Disappears in Time, because the tannin is transformed into gallic acid, and besides is precipitated by other principles contained in the wine, and by finings.
An Excess of Tannin is Avoided in strong, dark-colored, full-bodied wines by removing all the stems, and by early drawing from the tank. If the wines are inclined to be soft, weak, and with but little spirit, no attempt should be made to avoid roughness.
When wines are put into new casks, their roughness is increased by the tannin derived from the oak wood of which they are made; but during insensible fermentation a good deal of the tannin is thrown down with the vegetable albumen contained in the new wine.
How Removed.—If the wines are of good body and color, the roughness may be removed by fining them with a strong dose of gelatine, two or three ounces to 100 gallons. As this removes a portion of the color, it should only be resorted to in the case of rough and dark-colored wines, to hasten their maturity.
Bitterness and Taste of the Stems—Causes.—Bitterness is a disagreeable taste which, in new wines attacked by it, comes from the dissolution of a bitter principle contained in the stems, a principle entirely different from tannin. Sometimes it is communicated by the skins of certain varieties of grapes.
This is Prevented by allowing the grapes to reach complete maturity, and above all by stemming them all, and by not leaving the wine too long in the fermenting vat.
The Treatment is the same as for the earthy flavor, and also afterwards pouring in a quart or more of old brandy.
The bitterness here mentioned is only that met with in new wines, and its cause is entirely different from that found in old wines, which is described further on.
The Taste of the Stems, which often accompanies bitterness, is due to a prolonged immersion of the stems in the wine. It is supposed that this defect, which gives the wine a wild and common flavor, comes from an aromatic principle contained in the stems. It is prevented by stemming, and like natural bitterness, diminishes with time. The treatment is the same.
An unreasonably long vatting is one of the principal causes of bitterness and stem flavor.
Sourness—Its Causes.—Sourness, or heated flavor, as it is also called, is due to the presence of acetic acid in the wine. All wines, even the mellowest, the best made, and the best cared for, contain some acetic acid, but in so small a quantity as to be inappreciable to the taste. Acetic acid is produced in wines during their fermentation in open tanks, and is due to the contact of the air with the crust of the pomace. This crust or cap, formed of skins and stems, brought to the surface by bubbles of carbonic acid rising from the liquid, is exposed directly to the air, and the alcoholic fermentation of the liquid part is soon completed, and under the influence of the air and ferments, the alcohol is transformed into acetic acid. This transformation is so rapid that when the vatting is too prolonged, and the temperature is high, the exterior crust rapidly passes from acetic to putrid fermentation.
As long as the tumultuous fermentation continues, the crust is kept up above the surface by the bubbles of rising gas, but when it ceases, the cap falls, and settles down into the liquid, and the wine becomes impregnated with the acetic acid. The wine also, by simple contact with the crust, acquires a vinegar smell and taste.
Wines which become pricked by contact with the air after fermentation are treated further on under the head of Pricked Wines.
How Prevented.—The formation of acetic acid during fermentation is prevented by fermenting the wines in closed or partly closed vats, by avoiding contact of the air, by keeping the pomace submerged, and by confining the carbonic acid in the vat. If open vats are used, they should be only three-fourths full, so that a layer of gas may rest upon the pomace and protect it from the atmosphere; or the cap may be covered with a bed of straw as soon as formed. Care should be taken to draw off as soon as fermentation is complete.
Treatment.—Wines affected in this manner cannot be expected to acquire good qualities with age. They may be rendered potable, but their future is destroyed. Therefore, every precaution should be taken to guard against the defect. They should be separated from their first lees as soon as possible; consequently, they should be drawn off as soon as the gas ceases to rise. If they are still turbid, they should be clarified by an energetic fining, and they should be racked from the finings the very moment they are clear. They should be afterwards racked to further free them from ferments. If the wines are only heated, the odor of acetic acid will be sensibly diminished by the above operation; but if they are decidedly pricked, the means to neutralize their acid when drawn from the vat, as indicated for Pricked Wines, should be resorted to.
Alcoholic Weakness is due to a want of sufficient spirit, caused by an excess of water of vegetation, and the consequent lack of sugar in the grapes. In France this defect is generally found in wines coming from young vines planted in very fertile soils, or from the common varieties, pruned with long canes, and producing a great quantity of large, watery grapes. When wines weak in alcohol contain but little tannin and color, they rapidly degenerate, often commencing their decline during their first year, and before their clarification is completed.
How Avoided.—This defect can be corrected by planting the proper varieties of vines, and by avoiding rich soils; but in the climate of California there is but little danger of the wines being too weak, unless the grapes are late varieties, and grown in very unfavorable situations.
The Treatment of weak wines is to rid them of their ferments as soon as possible, in order to avoid acid and putrid degeneration, to which they are quite subject. This result is obtained by drawing them off as soon as the lees are deposited. If they remain turbid after the second racking, they should be gently fined with the whites of nine or ten eggs to 100 gallons. The coagulation of the albumen will be facilitated by adding one or more quarts of strong alcohol to the wine before fining, and by adding to the eggs a handful of common salt dissolved in a little water. But as these wines, by themselves, are short lived, it is necessary, in order to prolong their existence, to mix them with firm wines, strong in body and rich in color. By adding alcohol, they are still left dry and without fruity flavor, while if mixed with a wine of a flavor as nearly like their own as possible, and having a fruity flavor, and being firm and full-bodied, but not fortified, they will acquire mellowness as well as strength.
Want of Color—Causes.—As coloring matter is not found in the skins of grapes till they are ripe, green wines produced in years when the grapes do not ripen well, lack color.
The amount of color may be diminished if by excess of maturity the skins of the grapes decay.
The method of fermentation also influences more or less the richness of the color. Those wines, in the fermentation of which the pomace is kept constantly immersed in the liquid, dissolve out more coloring matter than those fermented in open vats in which the crust is raised above the surface of the must.
Some kinds of grapes naturally develop more color than others.
How Guarded Against.—It is therefore obvious, that the lack of color may be guarded against by gathering the grapes when they are just ripe, planting the proper varieties, and keeping the pomace submerged during fermentation, stirring it up, if necessary.
The Treatment should be such as to avoid as much as possible the precipitation of the coloring matter. They should, therefore, be fined as little as possible, and gelatine should be carefully avoided. If they must be fined, use the whites of eggs and in the quantity mentioned for weak wines—10 to 100 gallons.
Of course, their color may be increased by mixing them with darker colored wines, but in order not to affect their natural flavor, they should be mixed only with wines of the same nature and of the same growth.
It is not to be supposed that any one will resort to artificial coloring of any kind.
Dull, Bluish, Lead-colored Wine, and Flavor of the Lees—Causes.—Certain wines remain turbid, and preserve a dull, leaden color, even after insensible fermentation. This state may be due to several causes. Oftentimes young wines remain turbid because, for want of racking at proper times, and for want of storing in proper places, secondary fermentation has set in, which has stirred up the lees which had been deposited at the bottom of the cask. This also takes place when new wines are moved before racking.
Treatment.—In these cases, put them into a cellar of a constant temperature, leave them quiet for a couple of weeks, and see if they settle naturally. If not, clarify them by using the finings appropriate to their nature.
If they are turbid on account of an unseasonable fermentation, the first thing to do is to stop the working by racking, sulphuring, etc. When, in spite of all the cares that have been bestowed upon them, they still remain dull and difficult to clarify, while undergoing no fermentation, the cause must be sought in the want of tannin or alcohol.
If the difficulty is due simply to lack of spirit, the treatment consists in adding two or three quarts of strong alcohol to each 100 gallons, mixing with the wine a fifth or a tenth of a good-bodied wine of like natural flavor, and then by fining it with eggs as mentioned for weak wines.
If the dull wine has sufficient alcohol, as shown by a pronounced color, add about an ounce of tannin dissolved in alcohol, or the equivalent of tannified wine, and fine it with one to two ounces of gelatine.
Bluish or violet color, accompanied by a flavor of the lees, often occurs in wines of southern countries, and is due to an abundance of coloring matter and a lack of tartaric acid. When the violet-colored wine has a good deal of color, and more than nine per cent. of alcohol, the color may be changed to red by mixing with it from one-sixth to one-fourth of green wine, which contains an excess of tartaric acid, the natural blue color of the grape being changed to red by the action of the acid; then about an ounce of tannin, or the equivalent of tannified wine, should be added, that the color may become fixed, and that clarification may subsequently take place in a proper manner. In default of green wine, crystalized tartaric acid may be used, which is very soluble in wine. A small amount should be first experimented with, in order to learn just how much to use to change the blue of the wine to red, for we must not forget that this acid gives greenness to the wine and thereby renders it less healthful.
If the wines are so weak in alcohol that they have but little color, and that is blue and dull, they have a tendency to putridity. In this case, the blue color is in fact only a commencement of decomposition. It is due to an internal reaction which transforms a part of the tartrate of potash into carbonate of potash. Such wines have a slightly alkaline flavor, and left to themselves in contact with the air, they become rapidly corrupt, without completely acidifying. These wines are of the poorest quality. This disease, which is very rare, may be prevented by using the proper methods of vinification, and by rendering them firmer and full-bodied by the choice of good varieties of vines. In the treatment of such wines, some propose the use of tartaric acid to restore them. This will turn the blue color to red, but will not prevent the threatened decomposition. Mr. Boireau prefers the use of about one-sixth of green wine, which contains an abundance of the acid, and the subsequent mixing with a strong, full-bodied wine.
Putrid Decomposition—Causes.—Wines are decomposed and become putrid, on account of little spirituous strength and lack of tannin. The weakness in alcohol is due to want of sufficient sugar in the grapes—to the excess of water of vegetation. We see, then, that wine is predisposed to putridity when it is wanting in these two conservative principles, alcohol and tannin. Such wine quickly loses its color; it never becomes brilliant and limpid; it remains turbid, and never clears completely, but continues to deposit. The tendency to decomposition is announced by a change of color, which becomes tawny and dull, which gives it, though young, an appearance of worn out, turbid, old wine. Its red color is in great part deposited, and it retains only the yellow. If the defect is not promptly remedied by fortifying, it acquires a nauseous, putrid flavor of stagnant water; and it continues turbid, and is decomposed, without going squarely into acetous fermentation.
How Avoided.—To avoid this tendency, which is rare, means should be employed to increase the natural sugar in the must, and by planting proper varieties of grapes, which will produce good, firm wines, and by choosing proper situations for the vineyard, and employing the best methods of vinification.
Treatment.—Decomposition may be retarded in several ways: First, by fortifying the wines, by adding tannin to them, and by adding a sufficient quantity of rough, firm, alcoholic wine; second, in default of a strong, full-bodied wine, brandy may be added, or better, the tannin prepared with alcohol, so as to give them a strength of at least ten per cent.; third, fining should be avoided as much as possible, especially the use of finings which precipitate the coloring matter, such as gelatine; albumen should be used in preference, as for weak wines; fourth, the movements of long journeys, and drawing off by the use of pumps, should be avoided, for they are apt to increase the deposition of the coloring matter.
The treatment mentioned will retard the decomposition, but will not arrest it, and such wines can never endure a long voyage unless heavily brandied.
Several Different Natural Vices and Defects may attack the same wine, when it should be treated for that which is most prominent.