QUALITIES AND DEFECTS Of WINES
The art of wine tasting, like every art or science, has a language of its own, without which the taster could not properly express his criticisms, nor compare his opinions with those of other tasters regarding the same wine.
This renders it necessary to define or explain the various terms that have been adopted by tasters to express the sensations experienced by their senses of sight, smell, and taste, during the examination of a wine.
Persistent foam, as a rule, is characteristic of a wine poor in alcohol ; of a wine at a low temperature, or of a wine in need of racking, or, it may be, of a wine which is undergoing a slow fermentation, which may be either the normal and necessary alcoholic fermentation, or may be what is known as a secondary fermentation, in which case the wine is a prey to some malady — tartaric fermentation, for example.
The foam may also be persistent on account of effervescence, that is, the continued giving off of carbonic acid, which is dissolved in the wine, and which in escaping on the decrease of pressure forms little bubbles which renew the foam.
In the first cases cited above, the foam is usually limited to a more or less imperfect crown or ring of bubbles which form around the edge of the glass; or if the wine contains more than the usual amount of carbonic acid a bubble of gas will now and then be formed and rise to the surface.
When some disease is the cause of the persistent foam(1), especially if it be that known as " subbollimento, cercone, or vino girato" (vin tourne of the French), the circle formed is called " unghia " (nail), from which the expression " il vino fa V unghia net bicchiere.".
In the last case, when the persistent foam is due to effervescence, which may be of various intesities, several distinctions are made, of which the following are the principal:
This pricking is caused by the presence of a larger amount of carbonic acid than is normal to the temperature and pressure. The Tuscan usage of "governo" imparts this character to a wine.
" When the violent fermentation is over, throw in two handfuls of dried grapes to each vat; this will make the wine clearer and more piquant." — Davanzati.
However, Polacci rightly says: "For us a wine governato is always a defective wine."
Wines which are bottled young, before they are well defecated, or which contain sugar when bottled, easily become " spumeggiante " when kept in a cool place.
In sparkling wines, the carbonic acid is in solution at a relatively high pressure.
In these wines, after the first violent ebullition of gas, there is what is known as the "fontanella," sparkling, which is due to a continuous development of very small bubbles of gas, which, starting from certain points at the sides or bottom of the glass, rise like little chains of beads to the surface, where they cause the phenomenon known as pearling.
Of sparkling wines there are three grades, based upon the amount of foaming, or rather on the amount of carbonic acid which is given off, and on the length of time during which the foaming continues.(2)
These grades are:
In these wines the pressure approaches or surpasses four atmospheres. The maximum pressure that bottles will stand, without great danger, is about six atmospheres.(3)
Either too low or too high a pressure is a serious defect in sparkling wines. If the pressure is too low they do not effervesce; if, on the other hand, the pressure is too great, as in the case of bottles which the French call " recouleuses," there is a ruinous percentage of broken bottles, or if the bottles do not burst the cork is driven out, and most of the wine lost.
The carbonic acid which is dissolved in these wines, is produced by the fermentation of added sugar, or of a portion of that which the mxist contained.
As already stated, wines which have been fermented dry, and not with a view of making them sparkling, can be rendered so afterwards by being charged, at a high pressure and low temperature, with carbonic acid. On this is based the system of Carpene, a system now much used both in Italy and abroad.
Sparkling wines may be:
In various red wines the foam may present different colors, as:
After the foam is disposed of, the taster remarks on the degree of limpidity which the wine presents; a wine is said to be:
It may be noted here that clarification, unlike filtration, slightly modifies the composition of wine, as is proved by the quantitative determination of Professor Carpene, relative to wines that had been treated with white of egg. Following are the results of these determinations:
The quantity of albumen employed was about 100 c.c. per hectolitre ( 1 per m., or 1 pint to 125 gallons), which is a usual dose.
A wine from low-land grapes, in which tartaric fermentation has reached the stage of development when carbonic acid begins to be freely given off, is a good example of this condition.
This defect may be simply transitory, as when a wine has lately received some treatment, or an addition of alcohol or tavtaric acid, or directly after cutting or mixing wines, or when a wine has been much shaken or been exposed to too low a temperature. If the defect is permanent, it shows that the wine is diseased or ready to become so, or that the wine has been badly made. In the former cases the wine simply needs time to depose or an increase of temperature, when it will right itself. In the latter cases some special treatment is necessary, such as sulphuring, addition of tartaric acid, clarification, pasteurizing, etc.
A wine exhibiting this peculiarity is open to grave suspicion of un-soundness, if it is not already in an advanced stage of disease.
As an example of a wine in this condition, may be cited one which is, in the first phases of the disease, known as " subbollimento."(5) If a little of this wine is left exposed to the air it first becomes turbid, and loses its red color; then a precipitate forms and leaves a yellowish, sour, somewhat bitter liquid on top. As the disease progresses, if the wine is slightly shaken, mucous clouds will be seen floating in it, at the surfaces of which the above-mentioned phenomenon of interference may be seen.
In the time of Pliny, to describe the color of a wine they had only the four following epithets: album, fulvum, sanguineum, nigrum.
In those days they were easily satisfied; now we use the following terms to describe the colors of red and white wines:
Colorless wines are easily obtained from perfectly ripe white grapes, picked and handled with great care, and crushed when quite fresh and quite cool; then by exercising the most scrupulous cleanliness during the vinification and keeping of the wine, and by fermenting the must after it has been well defecated. If a wine is made which is not pefectly colorless, it may be rendered so by the use of animal charcoal, properly prepared, that is to say, in such a way as to prevent its diminishing the acidity of the wine. If this precaution is not taken, the wine, on account of its diminished acidity, will quickly turn yellowish on account of the formation of ferric compounds, which, under these conditions, takes place with great readiness. .
Regarding the wine of this variety, it is said that the Verdea of Tuscany is not so called on account of its green taste, but because of its greenish tint.
This color is sometimes produced artificially. In France they use extensively teinte de Fismes, so called after the town in which it is manufactured. It is claimed that it is free from alum and sulphuric acid,(7) but wrongly.
White wines which have commenced to spoil, or in which viscous fermentation has started, and which begin to become brownish, or even bluish, and at the same time turbid, what the French call vin oeil de perdriz, are rendered salable by the use of this teinte de Fismes, and are sold by the French under the name of vins roses.
Jacquesson, pere, states that this coloring fluid not only colors and clarifies the wine, but also arrests the progress of the disease, or prevents it if it is to be feared. This fluid is also used in France for coloring sparkling wines.
This phenomenon is observed not only in old but also in young wines, both red and white. Very probably its origin lies in several causes, as the numerous explications given by different authors would lead us to believe. Nessler has studied the change of color as it takes place in white wines. He tells us that the substances that cause the coloration, more or less deep, of the wine are contained in the stems and the seeds. Thus, wines which have been fermented in contact with the solid part of the grapes blacken very easily when exposed to the air. The presence of bad grapes in the fermentation also tends to render a wine liable to this discoloration
This change of white wine depends directly on the action of the air ; the wine loses its limpidity, becomes cloudy, and a black precipitate is formed; meanwhile the taste of the wine often changes. The black substance may be decolorized by sulphurous acid; the use of this substance arrests or retards the blackening of the wine.
Wines made from grapes poor in tartaric, malic acid, etc., like those which have been gathered when wet with dew or rain, or those which have been injured by cryptogams, are liable, when exposed to the air, to become cloudy and dark in color.
The presence of an excess of iron in the white wines of certain localities of the southern provinces is the reason why, when they are at all exposed to the air, their color changes to a blackish green.
Not southern wines alone, but also those from northern provinces, when they do not contain a sufficient quantity of acid, and more especially of tartaric acid, acquire this color. Chemists explain this phenomenon in different ways, though all admit that it is due to the presence of some of the compounds of iron. Nessler tells us that wines produced on soils rich in the salts of iron, and even wines which have been for any length of time in contact with iron, as happens when there is an iron rod between the heads of the cask, or when there are nails in the cask, etc., if they become exposed to the air, turn black, for then the protoxide or ferrous oxide contained in the wine changes in contact with the air to sesquioxide or ferric oxide. A black compound is then formed by the combination of the ferric oxide with the tannin; this black color is not obtained with the protoxide. Other chemists explain the phenomenon by supposing that there occur or are formed in the wine certain humic products analogous to those which are formed by the decomposition of vegetable substances. These substances are feebly acid, and have a considerable dissolving power on the iron. Thus there are formed in the wine certain of the lower compounds of iron, which, on exposure to the air, change to the higher compounds, and give the wine the blackish tint before spoken of. The wine then becomes turbid, and the flavor undergoes certain peculiar changes.
Formerly some sparkling wines were made of this color, but now it is no longer found but as a defect.
These wines form the connecting link between white and red wines. Trinci, writing of these wines, says: "The French 'claretto' is a smooth, vinous, lightly colored wine, with little aroma; slow and long in maturing, and not pleasing when drunk alone; blended, however, in proper proportion, it is extremely good.
These tints are seen sometimes in young wines, but less marked than in old; especially in those which, at first, have much of the bluish tint, and which deposit their color quickly.
Old wines often lose all, or nearly all, of their color, and become what is called " scolorito," decolorized or faded.
Wines may be divided according to intensity of color into deep-colored, medium-colored, and light-colored wines.
Deep-colored wines are harsh and indigestible.
(2) The French have a fourth grade, which they call Tissane, and which includes second and hird rate wines, which are, however, fairly drinkable.
(3) As a rule, authors give higher figures for the pressure of the various kinds of champagne that I have indicated, but the fat is, that my figures, if not too low, are certainly not too high. Of this, I am assured by Professor Carpene, who, in his experiements with sparkling wines, had occasion to test the pressures of many wines from the best accredited foreign and domestic houses.
(4)Old bottled wines may be turbid either because they nave become unsound, as happens ery easily when bottled too young, or because they have not been thoroughly defecated before being bottled, or it may be, because they have been moved in such a manner as to stir up the slight deposit which all wines throw down in time in greater or less quantities. If the ine is unsound there is no need of precautions, for the wine has become undrinkable; if, on the contrary, the turbid wine is sound it must be moved with the greatest caution, and toprepare it for the table it will be found useful to follow the rules of C. Ladrey, who writes thus:
"When the time arrives to drink a wine which has lain in bottle for some years, the first thing to do is to examine the bottle with great care when it is lifted up. It should be lifted up cautiously, retaining it in its horizontal position. By carrying the wine into the light, daylight or artificial, it is easy to ascertain whether the wine is perfectly clear or has a deposit. If, as may happen, the wine be perfectly clear, without trace of deposit, the bottle may be stood up and the wine served from it without decantation. This case, however, is very rare, and, especiallywith old wines, there is generally a deposit.
In this case we must be careful not to mix the limpid part of the wine with the deposit, and before raising the bottle up the wine should be decanted, which in its result is an operation actly similar to racking. This decantation should be made in the cellar, and demands some precautions. First the neck of the bottle is carefully raised, but not too high; it is then uncorked, care being taken not to subject it to any brusque motion either in raising it or in drawing the cork. The wine is then poured 'into another perfectly clean bottle, taking care to stop before the smallest part of the deposit has passed into the fresh bottle or decanter. The quantity of wine lost by this method is very small, and the wine that is saved can be drunk to the last drop. If, on the contrary, ;i wine which has only a very slight deposit is placed on the able without decanting, the second or third glass will commence to show a loss of brightness and the wine will have lost its agreeableness. There are some very simple machines made, which work on the principle of the siphon, and which greatly facilitate the operation of decantation."
(5)"La pousse", of the French, a kind of tartaric fermentation which is fully described on a subsequent page - trans.
(6)This yellow color may be natural and proper to the wine, or it may be a color which it has acquired from several causes, among which are some that have very grievous effects on the wine, and may be considered properly as maladies. The wines most generally subject to this disease of becoming yellow are those poor in alcohol, tartar, tartaric acid, and tannin, andwhich on the other hand are rich in malic acid.
I have already alluded to one of these causes above, namely, the presence of iron compounds. Some colorless wines, which are rather poor in acid, become, when placed in contact with the air, yellow or yellowish brown, in consequence of the formation of complex compounds, ferric, humic. etc.
The commonest causes of the yellowing of wines can be traced to the conditions under which the vintage has taken place- if, for instance, the season has been cold and rainy and the grapes have been gathered after the vines have in great part been denuded of their foliage, if the bunches contain decayed, soft, insipid grapes poor in acid and sugar, a wine of poor keeping qualities is obtained, and one very likely to become yellow, unless art conies to the id of nature.
Robinet, who has made special investigations with regard to the causes of this deterioration of white wines, distinguishes between that due to a fermentation caused by a mycoderm, and those due to chemical action, and among the latter he mentions some which give rise to the formation of malic ether, which reacts on the sugar. I should, however, remark here that after stating his belief in the formation of the malic ether, he declares that he has been unable to find the rational equation of the reaction or definite proof of its existence, but bases his belief in the formation of the malic ether on the taste and pronounced odor of cider which the wine acquires— an odor which is characteristic of the above substance.
Robinet also makes the important observation that during his researches he had noticed the isappearance of the glycerine from wines which were becoming yellow. This disappearance of the glycerine would lead one to believe that the reactions which take place are much more complicated than supposed by Robinet, especially in consideration of the fact that the glycerine is subject to transformations, like the other ingredients of wine.
Instead of trying to cure or ameliorate this defect in wines, it should be prevented, which can be done by the addition of alcohol and acids.
(7)The vin, or teinte de Fismes, was first prepared by Manceau by boiling elderberries and
(8)It sometimes happens, writes Robinet, that a perfectly bright white wine which has never been racked or otherwise treated before, is racked from its lees and treated with tannin and some clarifying material; then instead of becoming bright and clear the operations to which it h'as been treated have had diametrically the opposite effect. The wine has not taken the clarification, as the cellarmen say, 'has a bluish tint, and is turbid.
This change or malady of the "blue color" happens most generally in wines of low acid and alcoholic contents, and which are at the same time rich in nitrogenous sub- stances. Accqrding to Robinet this malady is due to a secondary fermentation, caused by a mycoderm which is analogous to the mycoderma crocceum, and has a very ephemeral existence.
To cure this disease in a wine it generally suffices to raise the alcoholic strength, or sometimes an addition of six or eight grains of tannin per hectolitre is necessary. In the latter case the wine is allowed to settle for twenty-four hours after the addition of tannin, and then clarified with isinglass.
The above mycoderm is killed and precipitated by cold.