Scientific American 3, 17.1.1863
We translate from a French scientific journal L'Invention, some accounts of the production and falsications of alcohol.
Alcohol, as we all know, is the product of the distillation of sweet liquors; we draw it by the distillation of wine, or cider, or beer, and all liquids which have undergone alcoholic fermentation. The wines which are gathered in France are not all destined to be consumed in nature. A part of the wines of the Meridian, from raisins (meaning grapes) rich in sugar, are converted into alcohol by distillation. We choose generally the white wines, which do not contain more alcohol than the red wines, but which furnish one more fine ad straight in taste; the alcohol which comes from the fermentation of raisins is ordinarily impure. It contains an essential oil which gives it in some cases an agreeable savor, in other a taste disagreeable. One can at least detect the presence of this oil in the alcohol of wine not rectified. In spreading the liquoe with six parts of water and distilling it with precaution, it remains in te cornue, an oily layer. This oil is very abundunt in the brandies which come out of the marc of the vintage; it is produced principally by the pellicles of the grain; one hundred litres of alcohol, separated, contains twenty grammes of this oily matter formed of the oil of the potato, of oily fat; of which a single drop suffices to indect one hundred litred of brandy. One can separate this oil of alcohol by a distilling pipe with management; in fact, the alcohol drinks at about eighty degrees, and the oil in question foes not enter into ebullition but between one hundred and thirty and two hundred degrees. The wines of the Dauphin and of the Vivarals of the Moselle give the alcohol which participates of the taste of terroir, that characterizes these wines.
It is probably to circumstances of this nature to which we must attribute the taste and bouquet in the old eau-de-vie de cogniac. During a long time brandy has been obtained through distillation by a naked pipe; unless one operates on white wine of a good quality, it is rare that we obtain an alcohol exempt from the taste of marc, or fire, contracted through this mode of distillation. The idea of substituting another mode for the one just mentioned belond to Argand, the inventor of the lamp with a double current of air, de quinquet. The processes of Argand were perdected by Edward Adams, who operated with an apparatus of De Wolf's, in which the flasks filled with wine were heated by steam. Once concedes that with this system, each flask, when unequally heated, gives an alcohol of different degrees. The processes of Adams were notably perdected by M. Blumenthal, who had recourse to a continuous mode of distillation, and knew how to combine the apparatus in such a manner that even during the drainage of the wines the distillation was uninterrupted. The wine arrives upon one side, while that which preceded it comes over upon the other, after having parted with the whole alcohol which it contained. This apparatus has, since M. Blumenthal, been perfected by M. Derosne, who prevented the depuration of some of the alcohol in the draining of the wines. This last perfection was till more simplified by M. Lngier. In submitting brandies to a new rectification, one obtains alcohol of three-sixths de Montpellier; it marks thirty-three degrees by the alcometer. The alcohol is received in vats, in which a part of the coloring matter is dissolved; this coloration becomes apparent as the sojourn of these liquids in barrels is prolonged. One is then disposed to allow more quality and vetuscity to brandies which are colored. Commerce sometime cuts the three-sixtsh of Montpellier with water, and colors it with an infusion of Caramel dissolved in tea, which seems to give this new brandy a taste of vetuste, but it is rare that this falsification escapes an experienced taster.
Wine is not the only substance from which alcohol is obtained; the beet, grain, potato, certain fruits, such as chestnuts, cherries, etc., produce alcohol a good quality of which different kinds are consumed in brandy. Brandies are mixtures of alcohol and water, and contain about equal parts of both liquids; spirits, in commerce, is an alcohol which contains less water than brandy. The richness of a spirit is always determined by the real quantity of alcohol which it contains; it is not the same with brandy, its color is not always proportionate to the quality of alcohol which it contains, more frequently it depends upon its age and growth. Experiments were at one time tried upon the spirits of commerce, by pouring it upon powder and then inflaming it, when the powder burned the spirit was judged to be of a strong quality; this is, however, no accurate test.
In France, the legal alcometer is that of Gay-Lussac; it expresses immediately the absolute quantity of alcohol which is contained in liquor; the experiment must be made at 15°, if the liquor has not this temperature it must be brought to it by the heat of the hand; for the rest, Gay-Lussac has given tastes of correction, which determine by the aid of the alcometer, the quality of an alcoholic liquid taken at different temperatures. The principal of graduating this instrument is simple; when put into absolute or pure spirit, it is sunk to the point marked 100°, placed in pure distilled water, and it stops at the point zero, the interval between those two points is then divided into 100° by the aid of mixtures of alcohol and water in proportions which are known - this instrument indicates the relations of volume, not of weight. In commerce, Cartier's areometer or liquor-weigher is still employed; in this instrment water which is distilled marks 10°, and alcohol "anhydre" marks 44°. Brandy from wine, originally has a whitish color, but tarrying in oaken barrels it acquires by age the yellowish-brown coloration which it ordinarily has, and which is due to the dissolution of a part of tannin and the extract contained in the oak. This brandy thus colored is blackened with a few drops of a solution of sulphate of iron. Brandy of a good quality possesses an aromatic odor, and a warm and clear savor, which is modified by time, the most esteemed brands are those of the Languedoc, of Montpellier and the district of Armagnac.