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.
Or fusel oil, grain oil, corn spirit oil. This oil is distinguished by a strong disagreeable odor that is perceptible in corn whiskey, and is vulgarly known as Rot-gut. Spirit distilled from grain, contains it in the proportion of one part in five hundred by measure. It is a colorless liquid, of a strong acrid burning taste - it is an artificial source of apple oil. Pear Oil and heavy Oil of Wine. - For the reader to fully appreciate what chemistry has done for the manufacture of liquors, in this single instance, take, for example, 100 gallons of potato spirit, which contains a larger portion of grain oil than any other spirit. Now this spirit will be, owing to this grain oil, of a highly offensive odor, and if drunk in the usual quantities that clean spirit is, it would act as an emetic. This grain oil is separated by distillation, which leaves the spirit clean and inodorous - a neutral spirit; the grain oil is then distilled with sulphuric acid, which produces oil of wine, or its odor; if this be added to the spirit, it would, in point of flavor, possess all the essentials of pure brandy. And if the oil be subjected to further chemical decomposition, the product would be apple oil and pear oil - the former added to the spirit would yield apple brandy, and the latter gives the appearance of age to liquors.
This is commonly obtained by the action of lime on muriate of ammonia or sal ammoniac.
Water of ammonia is used in low proof liquors, for giving in combination with ethers; essences, etc, a strong aromatic perfume; and it is used singly in a liquid that needs a strong odor, as, for instance, in a barrel of low proof whiskey, containing only twenty gallons of proof whiskey to twenty of water, will have an odor commonly galled "groggy," the addition of ammonia completely "cures ' this - that excess of ammonia should never be added that would indicate its own presence.
This substance is found floating on the sea, or thrown by the waves upon the shores of various countries, particularly in the southern hemisphere; is now generally believed to be produced in the intestines of the spermaceti whale. It is found in roundish or amorphous shaped pieces, usually small, but sometimes of considerable magnitude; and masses have been found weighing from 50 to 200 pounds.
These pieces are often composed of concentric layers; they are of various colors, usually grey, with brownish yellow and white streaks, often dark brown or blackish on the external surface. They are opaque, lighter than water, and of a consistence like that of wax, and have a peculiar aromatic agreeable odor, and are almost tasteless, and soften with the warmth of the hand. Ambergris is insoluble in water, but will dissolve in hot alcohol.
Ambergris is used as a perfume for liquors. It is never used alone, always being combined with other aromatics. The usual form of adding it to spirit, is to rub it well with sugar, which acts by minutely separating the particles of ambergris. Ambergris should be used in very small quantities, when used as a flavoring ingredient, as the odor would be easy of detection. In light-bodied liquors, one grain will often suffice. Its different applications will be found in the different formulas throughout the work.