Spiritus Frumenti (U. S. P.)—Whiskey.
Related entry: Alcohol.—Alcohol.
"An alcoholic liquid obtained by the distillation of the mash of fermented grain (usually of mixtures of corn, wheat, and rye., and at least 2 years old"—(U. S. P.).
Source and History.—According to the Standard Dictionary the name "whiskey" is derived from the Gaelic uisgebeatha, meaning "water of life" (uisge, water, + beatha, life). Whiskey, in this country, is generally distilled from the fermented mash made from mixtures of corn, wheat, and rye. In Great Britain barley, rye, and oats are most commonly used, while in Germany potatoes are the raw materials chiefly employed. Whiskey is generally named from its source as Rye whiskey, Corn whiskey, Potato whiskey, and when prepared from cider, as it sometimes is, Apple whiskey or Brandy. Scotch whiskey is distilled from barley. In all cases, a certain quantity of malted barley, must be mixed with the cereals, etc., in order that their starch be converted into sugar (maltose) which subsequently undergoes fermentation (see Alcohol). Sometimes conversion of the starchy material into sugar (dextrose) is effected by means of diluted acids (see Saccharum). To obtain the whiskey from the fermented mash, distillation followed by rectification is resorted to. The result of the first distillation is called low wines. These are rectified by a second distillation which first yields a milky spirit containing oily matters and is called foreshot; the clear spirit which follows is called high wines. The freshly distilled product, known as raw spirit or raw whiskey, is harsh and unfit for use. It is put into casks or tanks where it is allowed to remain for at least 2 years (ageing process), when it becomes mellowed and pleasanter in flavor, certain compound-ethers being developed.
Individual cereals have distinctive volatile constituents which impart to the whiskey a peculiar flavor and odor, and an expert may readily detect these distinctive differences. A most objectionable contamination of whiskey is the grain oil or fusel oil (amylic alcohol), which is generated during fermentation of the mash. Its boiling point being much above that of water and of ethyl alcohol, the greater part of it remains behind if the distillation be carefully conducted. Still, traces of fusel oil are generally present in whiskey. Amylic alcohol is the substance which imparts to raw spirit its disagreeable odor. In the ageing of the spirit, fusel oil is believed to be gradually oxidized and forms valerianic ether but some contend that it is partially converted into free valerianic acid. Among other constituents present in small quantities is oenanthylic acid; in old whiskey both acetic and valerianic acids are present, giving to the liquid a feeble acid reaction. (For an interesting account of the manufacture of whiskey, see C. K. Gallagher, Proc. Amer. Pharm. Assoc., 1883, pp. 375 and 477.)
Description and Tests.—Whiskey varies in color from pale-amber to deepbrown. When first prepared it is colorless, but upon standing in casks or tanks, it gradually assumes a brown color, which is also sometimes imparted to it by the addition of caramel. Both the odor and taste of aged whiskey is agreeable to most persons. It is officially demanded to be at least 2 years old, and to conform to the following requirements: "An amber-colored liquid, having a distinctive odor and taste, and a slightly acid reaction. Its specific gravity should not be more than 0.930, nor less than 0.917, corresponding, approximately, to an alcoholic strength of 44 to 50 per cent by weight, or 50 to 58 per cent by volume. If 100 Cc. of whiskey be very slowly evaporated in a tared capsule on a water-bath, the last portions volatilized should not have a harsh or disagreeable odor (absence of more than traces of fusel oil from grain); and the residue, when dried at 100° C. (212° F.), should not weigh more than 0.25 Gm. This residue should have no sweet or distinctly spicy taste (absence of added sugar, glycerin, or aromatic substances). It should almost completely dissolve in 10 Cc. of cold water, forming a solution which is colored not deeper than light green by a few drops of dilute ferric chloride T.S. made by mixing the latter with 10 volumes of water (absence of more than traces of oak tannin from casks). To render 100 Cc. of whiskey distinctly alkaline to litmus should not require more than 1.2 Cc. of potassium hydrate V.S. (limit of free acid)"—(U. S. P.). Mr. Joseph W. England (Amer. Jour. Pharm., 1897, p. 584) finds that the acid standard for a good whiskey should be at least 1.4 or 1.5 Co. of decinormal caustic potash solution, neutralizing 10 Cc. of whiskey, phenolphtalein being used as indicator.
Action and Medical Uses.—Locally, whiskey is applied to wounds, etc., for its antiseptic and stimulant effects. Internally it is employed for the purposes named under alcohol (see Alcohol). While less agreeable and less efficient than brandy, and differing considerably in action, even as one grade of whiskey or brandy may differ from another, it has come into almost universal employment instead of brandy on account of its inexpensiveness and comparative freedom from adulterants. It is less constipating than brandy but is more liable to offend the stomach, and to produce gastric, renal, and hepatic affections.