Section II The Tests, or Methods of Ascertaining the Good or Bad Qualities of Wines and Spirits
Though there are many tests in use for the discovery of the presence of mineral poisons, such as litharge and other preparations of lead, or pungent vegetable nostrums, namely extract of capsicums, &c. in wines and spirits, yet it must be admitted that there are no efficient tests for detecting the presence of the foreign agents above mentioned in either wines or spirits, except by chemical analysis; because, in the fraudulent combination which takes place, those articles bear the largest proportions which possess the same chemical properties as do the wines and spirits with which they are compounded. The injurious tendency of the vegetable poisons which form a component part of the spurious compositions which are vended under the denomination of cheap wines and spirits, and their injurious and lingering effects are so imperceptible on the human constitution, that, as the author of “The Oracle of Health and Long Life” observes, they must be deadly indeed to produce immediate injury, so as to give suspicion of their presence.
The presence of sugar of lead, or any other deleterious metal in wine, may be detected by filling a glass with wine, and adding a few drops of Harrowgate-water, or melted brimstone, when the wine will with the last mentioned ingredient becomes blackish, and with the other it will immediately produce a black sediment; but if it be unadulterated it will only lose its clearness, taste, and colour. Or the adulteration may be discovered by adding one part of water saturated with sulphuretted hydrogen gas, acidulated with a small portion of muriatic acid, to two parts of wine, or any other liquid, in which the presence of lead is suspected, when a blackish coloured precipitate will settle at the bottom of the vessel, which, being dried and fused by means of the blow-pipe, will yield a globule of metallic lead. The prussiate of potash is occasionally employed for the same purpose: a drop or two being sufficient to show a white or greyish precipitate in any fluid in which lead is contained. When white wines have an unusual degree of sweetness, are of a darker colour than their age and body seem to warrant, and particularly when their use, or that of the red wines, is followed by pains in the stomach, it may be concluded that they have been adulterated with lead.
The process to detect the presence of alum in wine, is to take some fresh prepared lime-water, and to mix the suspected wine with it, in about equal proportions; if after the mixture has stood about a day, a number of crystals is found deposited at the bottom of the vessel, the wine is genuine; but, if alum is present in the wine, there will be no crystals, but a slimy and muddy precipitate. Or the presence of alum may be detected, by dropping some solution of subcarbonate of potash into the wine, when, if the alum be present, there will be a violet coloured precipitate, or at least cloudiness, which will vanish again if a few drops of caustic, potash, or of muriatic acid are added to the mixture.
Where artificial colouring matter is suspected in wine, put a quarter of a pint of the liquor into a phial, with an ounce of fresh charcoal finely pulverized. Then shake the mixture well for a few minutes, when, if the wine is impregnated only with its own natural colouring, that colour will be chemically destroyed, and the wine, when filtered, will yield a clear limpid fluid; but, if the wine is artificially coloured, such artificial colours will not be acted on by the charcoal, and the mixture will appear unchanged.
Extraneous colours in wines may also be detected by means of acetate of lead. If this test produces, in red wine, a greenish grey precipitate, it is a sign that the wine is genuine. Wine coloured with the juice of bilberries, or elderberries, or Campeachy wood, produces, with acetate of lead, a deep blue precipitate; and fernambouk wood, red saunders, and the red beet, produce a red precipitate by the agency of the acetate of lead.
According to Cadet (Dictionnaire de Chimie, art. Vin.) this species of adulteration may be detected by pouring into the suspected wine a solution of sulphate of alumine, and precipitating the alum by potash. If the wine is pure, the precipitate will have a bottle green colour, more or less dark, according to the natural hue of the wine. But if the colour has been artificial the following will be the results:—
| Tournesol | will give a precipitate of | a bright yellow colour. |
| Brazil wood | a brownish red colour. | |
| Elderberries or privet | a brownish violet colour. | |
| Wortleberries | the colour of dirty wine lees. | |
| Logwood | a lake red colour. |
But Dr. Henderson says, in his learned work, entitled “The History of Ancient and Modern Wines,” p. 342, that the simple test pointed out to him by his friend Dr. Prout is equally satisfactory, and may be applied either to red or white wines. “On adding ammonia to wines, which had the appearance of being genuine, he observed that the precipitate was of an olive green colour; shewing the analogy between the colouring principle and the vegetable blues, most of which are rendered red by acids, and green by alkalis. This conjecture is, in some measure, confirmed by the recent discovery of M. Breton, professor of chemistry in Paris, with respect to the cause of that disorder in wines known by the name of tournure. Wine thus affected acquires a disagreeable taste and smell, loses its red colour, and assumes a dark violet hue, which changes are found to proceed from the presence of carbonate of potash, in consequence of the decomposition of the tartar contained in the liquor. To restore the natural colour and flavour, if the disease be not of long standing, it is only necessary to add a small quantity of tartaric acid, which, combining with the potash, forms cream of tartar, as is shown by the subsequent deposition of crystals. Revue Encyclopedique, November, 1823. In genuine wines, the colouring matter seems to partake of the character of a lake, partly held in solution by the excess of acid present, and partly combined with the earthy phosphates; for, in the precipitates obtained from these wines by means of ammonia, it appears in union with the triple phosphate of magnesia. Even the white wines of Xeres, Madeira, and Teneriffe, exhibit this mixed precipitate; their colouring matter being probably derived from the red grapes which enter into their composition. In fictitious wines, on the other hand, such as those procured from the black currant, gooseberry, orange, &c. the last mentioned salt was thrown down by ammonia, but more gradually, in less quantities, and without any admixture.”
The method of ascertaining the strength, or quantity of spirit or alcohol in wines is by the following process, for the discovery of which the public is indebted to Mr. Brande.
“Add to eight parts, by measure, of the wine to be examined, one part of a concentrated solution of subacetate of lead; a dense insoluble precipitate will ensue; which is a combination of the test-liquor with the colouring, extractive and acid matter of the wine. Shake the mixture for a few minutes, pour the whole upon a filter and collect the filtered fluid. It contains the brandy, or spirit, and water of the wine, together with a portion of the subacetate of lead. Add, in small quantities at a time to this fluid, warm, dry, and pure subcarbonate of potash, (not salt of tartar, or the subcarbonate of potash of commerce); which has previously been freed from water by heat, till the last portion added remains undissolved. The brandy or spirit contained in the fluid will become separated; for the subcarbonate of potash abstracts from it the whole of the water, with which it was combined; the brandy or spirit of wine forms a distinct stratum, which floats upon the aqueous solution of the alkaline salt. If the experiment be made in a glass tube, from one half inch to two inches in diameter, and graduated into a hundred equal parts, the per centage of spirit, in a given quantity of wine, may be read off by mere inspection. In the same manner the strength of any wine may be examined.”
The following is the proportion, or per centage, of alcohol or spirit in some of the most common wines and spirituous liquors. But such of my readers as may wish to gain more extensive information on the subject, I refer them to the first volume of the Journal of Science and the Arts, p. 290.
| Madeira | 24.42 to 19.24 | average | 22.77 |
| Sherry | 19.81 to 18.25 | average | 16.17 |
| Claret | 17.18 to 12.91 | average | 15.10 |
| Port | 25.83 to 19.96 | average | 22.99 |
| Champagne | 13.80 to 11.30 | average | 12.61 |
| Cider, highest average | 9.87 | lowest do. | 5.21 |
| Brandy | 53.39 |
| Rum | 53.68 |
| Gin | 54.32 |
| Whiskey (Scotch) | 54.32 |
| Whiskey (Irish) | 53.90 |
| Ale (Burton) | 8.88 |
| —— (Edinburgh) | 6.20 |
| —— (Dorchester) | 5.50 |
| London Porter (average) | 4.20 |
| Small Beer (average) | 1.28 |
The above proportional quantities of alcohol contained in the different kinds of wine are extracted from Mr. Brande’s experiments detailed in the work before mentioned; but as it appears that that gentleman made his experiments on samples of wine into which adventitious alcohol had been introduced, he seems in some instances to have assigned a greater degree of spirituosity to some wines than the subsequent analysis of Dr. Prout will justify, in the case of experiments made on genuine wines. To those who are desirous of informing themselves accurately on the subject, a reference to the Table at pages 363 and 364 of Dr. Henderson’s work on the History of Ancient and Modern Wines, in which the results of the experiments of Mr. Brande, Dr. Prout, and Mr. Zist, an able chemist residing at Mentz, are detailed, is recommended.
The quantity of astringent matter, or tannin, contained in wine, may readily be ascertained by dropping a solution of isinglass into it, when a gelatinous precipitate takes place in proportion to the tannin, whether it be Port, Claret, or Burgundy.
The adulteration and false strength of spirituous liquors, as brandy, rum, and malt spirit, are detected by diluting the suspected liquor with water, when the acrimony of the capsicum, or the grains of paradise, or pepper, may be easily discovered by the taste. Or by taking about a quart of the suspected liquor, and pouring it into a retort, or small still, and boiling it gently, until the whole of the spirituous part is evaporated, the residuum, if capsicum, grains of paradise, &c. have been present in the liquor, will retain a hot pungent taste. A ready way of detecting aqua-fortis, or oil of vitriol, in spirits, is, by dropping into a glass of the suspected liquor, a bit of chalk about the size of a pea, when the liquid, if spurious, will become like milk, but, if genuine, the chalk will lie at the bottom.
The adulteration of brandy with British molasses or sugar spirit, is ascertained by rubbing a portion of the suspected liquor between the palms of the hands, when the spirit, as it evaporates, leaves the disagreeable flavour which is peculiar to all British spirits. Or the liquor may be deprived of its alcohol, by heating a portion of it in a spoon over a candle till the vapour ceases to catch fire on the approach of a lighted taper. The residue thus obtained, if genuine brandy, possesses a vinous odour, resembling the flavour of brandy, whilst the residue produced from sophisticated brandy, has a peculiarly disagreeable smell, resembling gin, or the breath of habitual drunkards. The purity of spirits may also be easily ascertained by setting fire to a little of the suspected article in a spoon, when, if they be unadulterated, they will all burn away, without leaving any moisture behind. The presence of lead, or any of its preparations, in spirituous liquors, may be detected by the same method as has been stated in the case of wine. Where gin has been highly sweetened with sugar, by evaporating some of the suspected liquor in a spoon over a candle, the sugar will appear in the form of a gum-like substance when the spirit is volatilized.
The presence of lead as a component part of cider or perry, whether happening accidentally from the leaden bed of the press, or inserted intentionally for the purpose of neutralizing the super-abundant acid of the liquor, may be tested by putting a solution of molybdate of potash into the suspected liquor; when a white precipitate will take place, even though the lead should exist in the smallest possible quantity. It is needless here to enumerate the various tricks of “the knowing ones” for giving a factitious crust to wine bottles,G by means of Brazil wood and potash; or the colouring and eating away of wine corks,H to represent long residence in the neck of the bottle, though perhaps only driven in yesterday. Nor is the crusting even of the wine-casks, which is accomplished by means of crystals of the super-tartrate of potash, to be trusted to.
Those who wish to know the allowable secrets of the adulteration trade will find them fully explained in “The Private Gentleman or Importing Merchants’ Wine and Spirit Cellar Directory,” with many other “Secrets Worth Knowing” by cozeners; but it may be observed that the older port wine is, the less of the tartar, or super-tartrate of potash is contained in it, and the greater the deposition on the sides of the cask or bottle. But new wine may be put into old casks or old bottles. Therefore, to ascertain the quantity of the salt, take a pint of wine, and boil it down to one-half, into which drop a solution of muriate of platina, when a precipitate will take place, greater or less, in proportion to the quantity of salt contained in the wine.