Passing to the distillation and rectification processes, the aim in alcohol production is to obtain a highly concentrated alcoholic liquor, freed from all volatile implirities, and, so far as chemically pure; very elaborate rec tifying, stills are used. therefore, and the opera tion is eompleted filtration through wood or bone charcoal.
In the production of whisky the conservation of alcohol is not so important au object, and it is not desirable to eliminate all other volatile constituents, as some of them, when modified and mellowed with age, eventually impart to the liquor its line flavor; consequently, while the greater part of the fusel oil impurities are re moved, the rectifying process is not pushed so far, and the char filtration may be omitted entirely. Patent stills wherein fractionation is effected, like the Coffey still, produce a whisky which does not give the best results on maturing. This explains also why whisky made by crude and obsolete methods, such is Seot eh and Irish 'pot-still: whisky, often far surpasses in quality the produet of the most modern and best equipped distilleries.
The importance of the operation of aging in the production of whisky has already been al luded to, :mil constitutes the final and most im portant difference in the treatment of the two products. Alcohol is ready for sale and use as soon as it leaves the rectifying still and char filter; it is warehoused in barrels or casks which have been coated with glue or paraffin inside to prevent contact with the wood, and is with drawn tax-paid as soon as possible after it is warehoused, as it tends to deteriorate in time by dissolving coloring matter from the wood, not withstanding these precautions. Whisky, on the other hand, is entirely unfit for eonsumption when first produced, being fiery and unpalatable; it requires a long period of storage in wooden casks to bring about the changes in the second ary constituents which develop its aroma. It is sometimes sent on long sea voyages, stored in the bolds of vessels, this being supposed to have a favorable effect upon its maturing. Various quick ageing processes have been devised and some patented, but unite has so far proved a satis factbry substitute for the natural method. Chemically, the change which occurs in a ma tured liquor is considered as a process of oxidation, promoted by the porosity of the wooden cask (a liquor does not age in a glass or metal container), whereby the alcohols pres ent, amyl, butyl, propyl. etc., are converted into
the corresponding fragrant ethers, and possibly in part still further oxidized and elithinated. The liquor also acquires some new constituents from the wood of the cask, which is often charred inside, with the idea of promoting, chemi cal action. Freshly distilled whisky is, of course, colorless, and contains no solid matter whatever; after being stored in wood several years it has the amber tint familiar to every one, and contains perhaps 100 grains of solid matter per gallon—tannin, extractive and color ing matter—all derived from the oak wood com monly used in the harrels.
The importance of the maturing process is also recognized in the United States laws govern ing the production of whisky, and provided for by the privilege accorded distillers of deferring the payment of the gallon tax until the liquor is from bond ;' the bonded period may be extended as long as eight years with allow ance for loss by evaporation. during which time the whisky remains in a bonded warehouse mulet Government control. The Government stamp on whisky withdrawn from bond is practically a guarantee of its age and purity, and the act of March 3, IS97, known as the 'Bottling in Bond Act.' is intended to enable the purchaser of even so small a quantity as a quart to secure a prod uct which collies direct iron Government eon trol and has, therefore, suffered no addition or adulteration. The internal revenue strip stamp over the cork of the bottle is imprinted with the age and quantity of the contained whisky.
Whisky, in common with other kinds of dis tilled liquors, bears a heavy burden of taxation in the united states. (See INTERNAL I:EVEN UE SYSTEM.) The gallon tax has been $1.10 since 1b:14. which is at least four times the cost of production, and a yearly license, called special tax. is exacted from distiller, wholesaler, and retailer. The entire process of manufacture is subject to supervision by Government officers, and the distiller is held to a rigid accounting for all materials used he must pay tax upon not less than gallons of proof spirits for every bushel of grain mashed, whether he obtains that yield or not, and heavy penalties are provided for fraud or evasion of tax. 111 proportion to alco holic content the rate of tax upon distilled liquors is much higher than upon any form of fermented liquors. See LIQUORS, FERMENTED AND DISTILLED. STATISTICS AND HISTORY OF.