This section is from the book "The Manufacture Of Liquors, Wines, And Cordials, Without The Aid Of Distillation", by Pierre Lacour. Also available from Amazon: Manufacture of Liquors, Wines, and Cordials, Without the Aid of Distillation.
This is produced by the distillation of raisins. This spirit can be manufactured at that season of the year in which the previous year's stock of raisins have deteriorated from age. Spirit of raisins occupies a position, from its properties, near oil of wine, as they are obtained from the same sources, only under different circumstances; and as much of the original flavor of the raisin has been dissipated from age, this spirit is extensively used by all classes of manufacturers, and probably to a greater extent in France than elsewhere in flavoring clean spirit for brandies; and, also, for flavoring madeira, sherry, teneriffe, and all of the different brands of champagne. The process consists in using any well managed champagne, and adding the raisin spirit to the neutral spirit intended for the champagne. See the Formulas for Champagne.
Raisin spirit is sometimes adulterated with acetic ether, butyric ether, orris, nutmegs, apple oil, pear oil, etc, etc. The adulterations are sometimes carried to such extremes by some manufacturers that the so-called raisin spirit possesses none of the peculiarities of the original. The spurious raisin spirit is manufactured ex-tempore for auction sales, and is sold to the ignorant for brandy flavoring. The most common formula for this imitation is to take rectified whiskey (clear of color) forty gallons, sulphuric acid three ounces, acetic ether twelve ounces, essence of orange four ounces, ambergris two grains, rubbed up well with two ounces of dry white sugar, and added to the forty gallons of whiskey. This liquid is then charged with from fifteen to twenty-five gallons of water containing pellitory, grains of paradise, and catechu; and again the spirit is not diluted with water, but the strength is heightened by the addition of from six to twelve ounces of sweet spirits of nitre, combined with a quart or three pints of tincture of grains of paradise. The consumers of this latter article are coffeehouse keepers, etc, etc. It is for flavoring and giving a false strength to liquors, wines, etc.
And even the distiller becomes imbued with the spirit of the age; for if the manufacturer operates on his customer's purse through the medium of his olfactory nerves, the manufacturer, by the same rule, is done equally as "brown" by the distiller; because the adulterations that the raisin spirit is liable to contain coming from the hands of the distiller are various, and among the most prominent, and at the same time difficult of detection, are the different ethers.
We have no positive chemical tests for ethers, but their volatility will serve to detect their presence. Thus, for instance, if a portion of suspected raisin spirit be exposed, in an open-mouthed vessel, for a few hours, the pungency and odor of the sample will be greatly lessened, or entirely dissipated. To detect any acrimonious substances, evaporate a quan tity of the spirit to dryness, and the different sub ptances will be perceptible to the taste. In separating the ether from the spirit by evaporation, the operation will be greatly facilitated by heating the spirit to a point below the boiling point for one hour; and if the odor has undergone no perceptible change, allowing a small per centage for evaporation of the natural bouquet of the raisin spirit, which, it must be recollected, is not of that volatile nature that the ethers are.
Raisin spirit has its perfume varied by the addition of various perfumes. Thus, for instance, in the imitations of the fancy brands of the American bottled whiskey, the essence of wintergreen, or essence of pear oil, is added to the raisin spirit in such quantities that will change the general tone of the original odor to that required.