I will now pass in review the qualities and defects of which the senses of taste and smell take cognizance.
The aroma is the odor which comes from the skins of aromatic grapes,(1) and varies in quantity and quality, according to the variety of grape and the degree of its maturity. It passes into the wine in wine making; the aroma therefore exists in the grapes as well as in the wine.
The bouquet is due to the volatilization at ordinary temperature of certain substances known as ethers, which are formed by the reactions of the acids and alcohols in the wine during its process of aging. (3) Thus, the bouquet is not to be found ready formed in the grape, as is the case of the aroma.
The bouquet and aroma affect the senses before, the seve after drinking the wine.
Seve, which is especially the property of fine wines, is due to the presence of certain substances which are formed in the grapes during the short time preceding their complete maturity; these substances are peculiar to certain varieties of grapes, and owe their existence also to careful cultivation, as well as to certain conditions of climate and soil.(4)
In analyzing wine, writes Faure, I have observed that fine and delicate wines, those renowned for their flavor and general high quality, contain a certain glutinous, viscid substance, which exists only in almost inappreciable quantities in ordinary wines, and is quite absent from inferior ones.
This principle, to which wine owes its seve, has been called by Faure cenanthin(5) or flower of wine, and is only found in grapes which are completely mature. Some vineyards, which usually produce grapes containing this substance, fail to do so in stormy seasons. The only vines containing it in such years are those produced on dry sandy or gravelly soils. The same variety of vines, which, when grown on an appropriate soil, gives a wine full of seve, will, when grown on a rich, heavy, or clayey one, produce a wine containing little or no cenanthin.
Thus it can be seen that the preeminence of high-class wines ia not due to the caprice of the taster, but to actual differences of composition, and to the presence of principles not found in inferior wines.
The ordinary wines of the three communes of the Gironde, where the four high-class Bordeaux wines are produced, are, in general, poor in cenanthin. These four wines, however, contain a larger quantity of the substance, as may be seen by the following:
OEnanthin contained in vines of —
An insipid wine may have plenty of color, however. Insipid wines are very subject to unfavorable changes.
When a wine is made mute by the use of sulphurous anhydride, the risk is run, if too much is used, of giving the wine, first, a taste of sulph- hydric acid, and afterward more or less pronounced bad flavors due to the sulphates that are formed. These wines are kept in cool cellars, where the temperature is as nearly as possible constant, and in strong and well-hooped casks. They ought to be clarified, prefereably with gelatine. In order to obtain a perfect clarification, about 8 or 10 grammes of tannin are added to each hectolitre before putting in the finings (one tenth per m., or about 1.25 ounces per 100 gallons).
This quality is due to the presence of a certain quantity of glycerine, and not to glucose, as at first one might be inclined to think. In this latter case the wine would be called "amabile" (fruity).
It is glycerine rather than glucose which gives a wine that kind of smoothness which might almost be called nnctuosity.
In very high-class wines the smoothness or unctuosity is due not only to glycerine, but also to other bodies which have not yet been well studied; they occur more especially in wines of very favorable years; that is, of years when the season has been so propitious that the grapes have been able to attain an exceptionally perfect maturation.
Many chemists have attempted to determine the nature of these substances. II Faure, who studied the wines of the Gironde, believes that this unctuosity is due to the same substance as seve, a substance which is of similar character to pectine and mucilage, and which he called "oenanthin." Batilliat claims to have found in the high-class wines of Bordeaux the peculiar substance which causes their unctuosity, and which he calls " croatine."
Mulder, on the other hand, from observations made on the wines of the Gironde, considers this unctuous substance as analogous to dextrine.
Whatever may be the nature of this substance, it is useful to know that the wines in which it occurs, if not well kept, are liable to undergo an almost insensible fermentation, which destroys this substance, and so takes away from the wine that quality which is due to it; pasteurizing or heating will also deprive a wine of this quality.
As is said sometimes: " Quel vinctto cosi amabile va giu senza accor- gersene."
Technically, a fruity wine cannot be said to possess seve because it tends towards sweetness. However, a wine which is very slightly sweet may possess a good seve in the sense that it produces those sensations which are the quality of wines of the highest class.
Another cause of variation in the character of wines is the deposition in whole or in part of various substances on the walls of the cask, or in the form of lees at the bottom, that are thus eliminated from the composition of the wine.
These young wines, compared with their condition at maturity, are more heavy bodied, more deeply colored (green or acid), more astringent, and sometimes rough and harsh.
These wines are, finally, more nutritious than after they become mature; it must not be forgotten, however, that a wine which is too young is somewhat indigestible.
A wine is said to be green when it has an acidity and roughness which, though pronounced, is of such a character that it will disappear with time.
Thus, incompletely ripened grapes give a green wine, owing to a small quantity of volatile acid and acid salts which they contain, and more especially bi-tartrate of potash.
Greenness is characteristic of certain new wines, and also of many mature wines produced in northern countries.
Wine produced from grapes which for some cause or other have not reached their maturity, are always more or less harshly acid.
With time this repellant acidity disappears, for the reason, according to Dessaignes, that the malic acid, after eight or ten months, decomposes into succinic and butyric acids(10)
A decrepit wine has lost its fragrance, has become flat; it has not contracted any disagreeable or repelling flavor, for the taste of age that these wines have cannot be called disagreeable in the same sense as a wine which is attacked by the disease called bitterness, but it has a slight bitterness which recalls that of some resinous substances.
These wines, when they find themselves in favorable conditions, as when exposed to the air, decompose readily.
"A wine which has been exposed to the cold of winter and the heat of summer acquires in the month of September the taste which Italians call 'settembrino,' which is exhausted and 'passe.'" — M. Salvini.
In drinking a rough, overastringent wine, a feeling of dryness is produced on the tongue and along the oesophagus. The daily use of wines of this character, by persons of delicate constitution, may occasion organic disorders.
This roughness tends to diminish with time, and may completely disappear; the cause being that the tannin, under the influence of oxygen, gives place to a slow formation of carbonic and gallic acids.
OEnotannin (12) possesses tonic properties, and insures the conservation of the wine by causing coagulation, and consequently the elimination of many substances which the wine contains, substances whose presence is dangerous from their instability, and because they favor the development of those organisms to which are due secondary fermentations.
High-class and fine wines when young, and even sometimes when old, are more or less markedly rough; this roughness they lose with time.
Harshness, of itself, is a defect; ordinarily it is due to the soil, and in that case the wine is also heavy bodied. This defect may also be owing to unskillful preparation or handling.
Harsh wines keep easily, and can be kept for a longer or shorter time, according to their quality.
The life of ordinary or common wines, which are harsh, is limited to a few, two or three, years. These wines in losing their harshness gain little or nothing in value, in fact, as they lose the defect of harshness, they acquire another, that due to tartaric fermentation.
Harsh wines which have good quality and body keep for a long time, and after some years lose their harshness; they thus become more homogeneous, harmonious, and pleasing, or as the experts express it, they become rounded.
If these wines are drunk before they have lost a portion of their harshness, they are not very hygienic.
Very often this quality is due to the presence of carbonic acid in solution; for example, in young wines or those which have been treated by the Italian method called "il governo."*
Sometimes, in the common language, all wines are called bitter, but with impropriety, which are not sweet; from which the Tuscan proverb, Vino amaro ticnlo caro, which means, the wine which is not sweet is always of best quality.
Wines of this kind have a harsh, repelling, nauseating bitterness, due to secondary fermentations, or in the case of young wines, to principles which they have extracted from the skins or stalks during fermentation. According to M. Nessler the tendency of a wine to this disease is augmented by remaining long in contact with the pomace.
The bitter taste affects principally the posterior portions of the tongue and palate, and the sensation persists for some time.This fault, which most oenologists consider confined to red wine, is found also, we are told by M. Ottavi, in white wines. He claims to have encountered it in the white wines of Piedmont.
Nessler observes that white wines are less subject to this defect or malady than red, thus admitting, by implication, that they do sometimes become bitter.
The bitter secondary fermentation may develop in any wine, but is more frequent in fine and delicate wines. In common wines the disease usually occurring is the tartaric fermentation. In general, highly colored wines, rich in extractive matters, are most liable to the attacks of the disease of bitterness.
The high-class wines of Bourgogne, made from the Pinot, not excluding even those made in the most favorable years, are subject to attack by this disease.
In the finest wines Vergnette Lamotte distinguishes two kinds of bitterness:
Pasteur holds that even this second bitterness, which Vergnette Lamotte lays to the account of decrepitude, is caused by the same organism which determines the first kind.
This organism may remain inert for a longer or shorter period, till in the course of aging the wine presents the necessary favorable conditions for its development.
In conclusion, I will say that the bitter taste is a somewhat serious defect; a defect which may be more or less marked, as it may be transitory or permanent.(13)
In tasting, these flavors are perceived by the posterior part of the mouth, and may have their origin in the soil, in the use of inappropriate fertilizers, in the plants supporting the vines, or in the weeds infesting the vineyard, etc.
"The earthy taxte is a vague term," writes Ottavi, and with justice, for it is a taste which is not always very definite, resembling sometimes earth, manure, flint, slate, nuts, willow, grass, etc. It is well known that Aristolochia, Mercurialis, etc., if allowed to grow in the vineyard, communicate their flavor to the grapes, and therefore to the wine. Pliny was not mistaken when he wrote: "In general, the vine takes up with an astonishing facility the flavors of neighboring plants. The grapes grown in the marshy soils of Padua have a taste of willow."
Generally the earthy taste is not found in high-class or fine wines. I say generally, because there are exceptions; for example, Chablis has a slight flavor of flint, and yet it is a wine of a certain renown.
The flinty taste, writes Petit Lafitte, has something vinous and energetic, which exactly recalls the sensation experienced by the olfactory organs when a flint recently struck by the steel is held under the nose.(14)
According to the experiments made by Aubergier, the principle to which wines owe their earthy taste is found neither in the seeds nor in the stems, but in the skins of the grapes. From 15 kilogrammes of pomace he extracted 30 grammes of a volatile oil so acrid and penetrating that a single drop was sufficient to infect 10 litres of the best brandy, f This fact supports the opinion of those who see in the prolonged contact of the wine with the pomace the cause of the earthy taste.
Certainly, by improving the soil, by the use of proper fertilizers, by a good defecation of the must, by a prompt removal of the wine from the pomace, by clarification and rackings, the taste under discussion is much diminished, and sometimes completely eliminated.
This taste is caused, also, by an over-maturity of the grapes, as happens in very hot weather, and especially when the grapes are thick- skinned; it may be caused, also, by frozen grapes, or by the freezing of the wine; in the latter case especially when the pieces of ice formed in the wine are not carefully removed.
The aroma most highly appreciated was that obtained by the addition of myrrh. We read, in fact, in Pliny: Lautissima apud priscos mna erant mi/rrhss odore condita, ut adparet Plauti fabula, quae Persa iscribitur, quamquam in ea et calamos addijubet. Peppered wine, which was prepared by fermenting the must with apples and pepper, was very much appreciated in the time of Pliny.
(2)Even the bouquet of wines has not escaped imitation and adulteration. The manufacture of artificial bouquets or perfumes for wines has become a regular industry in France and Germany, where it is carried on on a large scale. There is a large consumption of such articles as "bouquet" of Pomard, or of Bourgogne, extract of Bourdeaux, the "Kancio des vins," "seve" of Baumfi, of Medoc, of St. Julien, of Champagne, of Sillery, etc.
The substances most usually employed to add an artificial bouquet to dinner wines, are: Florentine iris, raspberries, cloves, vine flowers, mignonette, nutmegs, bitter almonds, etc. To these should be added certain chemical products which are prepared more especially in Germany. All these attempts to imitate nature have been but very partially successful.
A wine may be perfumed artificially, but it is impossible to give it "seve." This artificial perfume is always too pronounced, and is never as delicate as the natural bouquet of wine. These artificial bouquets impress the sense of smell, but not that of taste. If a perfumed wine, then, is tasted without being smelled, its natural " seve " can be distinguished. Artificial aromas are not lasting, and gradually disappear from the wine.
(3) Chemically, the difference between aroma and bouquet is, according to Maumene' and Berthelot, the following:
The former is due to certain hydro-carbons and to the products of their oxidation;perhaps, also, as Ordonneau states, to the ether of a high, fatty acid produced by intercellular alcoholic fermentation, and which, being fixed, remains in the pellicle; this has enabled the experimenter to obtain it from the pomace of Polle Blanche.
The latter seems to be due to a mixture of aldehydes with one or more essential oils and of numerous ethers, the product of the combination of fatty and other polyatonic acids with ethylic and other alchohols; there are, for instance, valerian, amylic, propylacetic, etc.
(4)The result of many observations and studies regarding the influence of soil composition or the character of wine, may be summed up as follows: High alcoholic strength is characteristic of wines grown on calcareous soils; color depends on the iron in the soil; smoothness on the alumina and on the variety of grape; bouquet on the silica.
Chambertin, writes Julian, is a wine which has a good color, much seve, is very delicate and smooth, faultless in taste, and possessing the most agreeable bouquet.
The vineyard which produces this wine has the following soil composition:
(5) By oenathin should not be understood, as perhaps was done by Faure, a single chemical compound, but rather a comlpex mixture of ethers.
(6)With regard to tastes in general, writers are at variance. The greater or less number of tastes and the possibility of their classification have been discussed. The number of tastes may be considered as infinite, and therefore a classification almost impossible. Such classification, however, has been attempted. Ilaller distinguishes twelve tastes, which have been reduced by Linmuus to ten: sweet, acrid, fatty, astringent, bitter, viscous, saltish, watery, and insipid. Vintschgau proposes another taste — metallic.
Physiologists distinguish in the sense of taste four specific energies, that is, four elementary sensations, viz.: sweet, bitter, acid, and salt. The first two affect only the nerves of taste; the acid taste, on the other hand, if too strong, may cause pain, for which reason Vintschgau believed that acid and salt tastes affect also the sense of feeling, as is seen in touching concentrated solutions of acids.
Nothing is known with certainty as to the way in which different tastes are distinguished, and we must be content with supposing that each flavor — sweet, sour, bitter, salt — acts upon special nerves which serve to distinguish them. This is the more probable, as different parts of the tongue are unequally affected by different tastes. We are still more in the dark regarding the intimate nature of the tastes, the chemical composition of the substances which they characterize seeming to have no connection with them.
The chemical composition of a substance has nothing to do with its sweet, bitter, or salt taste; with regard to the acid taste, however, it may be said that every substance which tastes acid is also an acid from the chemical point of view.
(7)The vineyardist in making a choice of varieties to plant should keep in view the flavor which they will give to his wine. If he is planting in a new locality, where it cannot be known what kind of grape will there best develop its flavor, he should choose a variety which gives a wine of neutral taste. The French, who are masters of the art of imitating wines, have this maxim: "There are more buyers than there are connoisseurs."
Trusting to the truth of this saying, they have been able to establish that great commerce of wine which has become one of the principal sources of riches to France. The cities of Cette, Bordeaux, Marseilles, Lunel, Montpellier, and others of the south of France are centers of the production of large quantities of " wines of imitation." Do you wish to make, for example, a hectolitre of fine Bordeaux ?
This, however, is too expensive a Bordeaux; here is a cheaper one:
If a still cheaper Bordeaux is desired —
The above information is for the edification of those who prefer a bottle of this bordeax to a bottle of Chianti of Valpolicella of Valtellina, and many other italian wines which are fare superior to these French concoctions.
(8) Many use this word in a somewhat different sense; by it they mean "wine-like", that is, having a full supply of the quality or qualities which preemintently distinguish wine from other alcoholic beverages—trans.
(9)This acidity must not be confounded with that due to the acetification of the wine. This excessive acidity may be amended by an indirect method, which is that suggested by Gall, and which aims to correct the must before fermentation. Or some may have recourse to "marmorizzazione;" that is, the addition to the wine of powdered calcium carbonate (marble), which is, however, a method which cannot be very highly recommended, and when necessary, Liebig's method is much to be preferred. This method is to add to the wine a concentrated solution of neutral tartrate of potash in such proportion as to bring down the acidity to the desired degree.
As a preliminary test, to ascertain with an approximation near enough for practical purposes, several quart bottles are filled with the wine to be treated, and to each bottle is added a certain quantity of the solution of neutral tartrate of potash, each bottle being given a slightly greater dose than the one before. The bottles are then corked and left to themselves for a few days. They are then tasted, and the one giving the desired result is used as the basis of calculation for treating the whole quantity.
(10)The organic acids contained in the must are the following: Tartaric, racemic, malic, citric, tannic, palmitic, stearic, etc.
(11)This is a restricted use of the term dry, somewhat different from its more general meaning, which is simply not sweet, that is, containing no glucode - Tran.
(12) OEnotannin has the property of forming with gelatine and with albumen voluminous insoluble compounds, which precipitate with great readiness. By means of clarification, therefore, the contents of oenotannin can be notably diminished, thus curing, or at least considerably lessening, the defect of roughness.
I have called roughness a defect, but that should be understood relatively, not absolutely, for it should not be forgotten that the general trade demands a certain roughness, and wines in which it is lacking are often given this character artificially by tne addition of alum, which is undeniablv an adulteration, or by the addition of tannin.
Alum is used by unprincipled dealers, and has the quality of reviving the color, precipitating the albuminoids, and imparting a roughness, almost styptic, analogous to that presented by the common Bordeaux wines.
The wine maker has the choice of two kinds of tannin which are found in commerce, and which differ in their mode of extraction or preparation. Thus, the tannin may be extracted from galls by means of ether, giving a tannin pure, but retaining a taste of ether, which renders it objectionable in the treatment of wine. The other kind, which is extracted by alcohol, is inodorous, and therefore preferable for the wine maker.
Pure tannin dissolves completely in alcohol, and in water mixed with 10 per cent of alcohol, and the solution should be limpid. When the wine maker needs tannin he can make use of the grape seeds, which contain a considerable quantity; the seeds may be used either fresh or dry, the latter being more convenient, as they can be preserved from year to year.
It is to be remarked that clarification attempted with isinglass, gelatine, or white of egg, does not always succeed; the failure is due to the lack or insufficiency of tannin in the wine, or to its superabundance.
This explains the common usage of adding tannin to white wines before attempting to clarify them; or in the case of highly tannic red wines why, after adding the clarification, it is often necessary in order to produce perfect limpidity, to have recourse to sulphuring and racking. This is what the cellarman means when he says that the wine has not taken the finings.
Wines which have fermented slowly, and which contain substances resembling humic compounds, can sometimes be fined even when lacking in tannin.
It is also worthy of remark that tannin has a great influence on the color of wine; it tends ot increase it, and, according to M. Nessler, if the wine remains for some time in contact with the lees, it prevents, to a great extent, the dimunition of the color.
(13) The bitter taste in wine may be the consequence of imperfect maturity of the grapes, owing either to an unpropitious season, or to the damage caused by insect or crypto gamic pests; or it may be the consequence of a secondary fermentation, caused by a micro-organism, i. e., the "bitter ferment," which determines the formation of those substances which impart this taste to the wine. In the latter case we have a true disease.
When the bitterness is due to the principles which have passed from the grapes and stems into the wine, then with time and successive finings and rackings it will disappear. This is explained by the supposition that the nitrogenous substances become impregnated with the bitter principles, and thus, when the former are precipitated, they carry along with them the latter, the wine in this way losing this defect.
The bitter taste, if very pronounced, may not disappear after the first rackings, in which case the wine should be fined with gelatine or white of egg.
If the wine be weak, the coagulation of the albumen may be facilitated by the addition of alcohol. According to the quality of the wine, it may be given a light clarification with the whites of three or four eggs per hectolitre, or a more energetic treatment with 25 grammes of gelatine.
Such a treatment not being found sufficient recourse must be had to the use of olive oil of good quality; of this the dose to be used is one half litre per hectolitre. The oil is poured into the wine, the whole thoroughly stirred, and then allowed to rest; the oil separates from the wine, and carries with it the substances which have caused the bitterness.
Directly after racking a wine with access of air, it will sometimes become slightly bitter; this seems to be caused by the action of the oxygen of the air upon substances contained in the wine; later the bitterness disappears, owing very probably to the rapid oxidation which causes these substances to precipitate. In this way M. Mona explains how bitter wines in bottles can, with time, lose this defect. Formerly various opinions were held regarding this malady, because, in all probability, people failed to distinguish between bitterness proper and the malady due to tartanc fermentation, or " la pousse'
Thus De Blassis attributed it to changes of the salts, especially of bi-tartrate of potash; Machard to an invisible action of the fermentative principle, decomposing the last remnants of sugar and salts in the wine; Lebceuf to an abnormal fermentation, which produced, sometimes, citric ether, which has a bitter taste; Vergnette Lamotte to a secondary fomentation, caused by a parasitic vegetation, which decomposed the wine in consuming the coloring matter; Neubauer found that the quantity of tannin and of coloring matter diminished with the progress of the malady. Finally Pasteur, after the study of many bitter wines, has demonstrated that this malady is caused by the action of a micro-organism, which multiplies with extraordinary rapidity in the superior wines of the "Cote d'Or," but very slowly in the common wines 01 liourgogne, the Jura, and the Bordelais. lie adds that this malady presents many diversities in its development, according to the origin and the nature of the wine, but that all wines are subject to it.
Ducleaux, in 1873, determined the volatile acids of bitter wines, the following being the result of his analyses :
The inrease of total acidity in the sick wine being greater than could be accounted for by the formation of acetic acid at the expense of the alcohol, it ust be attributed to the fermentation of the glycerine, which, in fact, had diminshed.
The diminution of the glycerine was also pointed out by Pasteur, who, besides, stated that the tartaric acid did not diminish. As the researches of Fritz have shown, many microbes are able to cause fermentation of the glycerine ; thus, under the action of the Bacillus butylicun it is transformed into butylic alcohol and butyric acid.
Recently, B. I lass experimented with a view of ascertaining whether the bitter taste was due to citric ether, as Miiller and other French chemists had supposed, or to some resinous substance produced by changes of the aldehyde in presence of ammoniacal compositions having their origin in the albuminoid matters of the wine. By exhausting a wine which was afflicted with the bitter disease, and which he had previously rendered alkaline with ether, he obtained a resin slightly soluble in water, very soluble in alcohol and in acetic ether, insoluble in carbon bi-sulphide, turning brown in contact with the alcohols, becoming greenish with ferric chloride, and having the extremely bitter taste of the diseased wine.
Hass has found by his experiments that the best way of curing a wine afflicted with this malady, is by the use of oxidizing agents. Oxygenated water in small quantities is inefficacious ; in larger quantities it destroj'S the bitter taste, but produces another not less disgusting. The best results have been obtained by aeration.
The wine is fortified by the addition of alcohol till it contains 13 per cent by volume, if of feeble character and liable to acetify. A current of air is then passed through the wine for two hours, and the bitterness disappears completely.
Filtration through pomace or cellulose has an excellent effect, the bitter substance seeming to be removed by physical attraction. This disease may be said to have several stages. At first the wine is still clear, but less fragrant, duller in color, and with a slight bitter taste. Later it acquires an odor sui generis; the bitter taste increases, becoming piquant on account of the small quantity of carbonic acid produced by the secondary fermentation which takes place. Finally it loses its natural color, becoming brownish, with a tendency to blue; there has then taken place a serious change in one of the principal components of the wine — the extractive matter — and the wine has become an undrmkable liquid.
(14)According to Doussieux, the earthy taste is due probably to the solution and evaporation of a part of the mineral and metallic substances which are found in the soil of certain vineyards.
Petit Lafitte seems inclined to attribute the flinty taste to iron and alumina. Ladrey, on the other hand, accounts for it by the presence of much silica in the soil, and many analyses show silica not only in the leaves and seeds of the vine, but also in the wine.
Joulie states that the flinty taste isdue to the fact that pyroniac silica contains a bituminous substance of organic origin, the peculiar taste of which is communicated to the wine.
Regarding the quantity of silica contained in wine, we have the analyses of Boussin- gault, who, in analyzing his wine grown at Smalzberg (Bas Rhin), found 6.096 gr. of silica per 1.870 gr. of ash in a gallon of wine, 5 per cent of the mineral ingredients.
Grasso, in the ash of four different musts, found the following quantities of silica:
In the skins the proportion was greater; in those of the first it was 3.464, and 2.571 in those of the fourth.