Whiskies in America are very rarely made from pure barley malt. There are some exceptions, and a few distilleries make pure malt whisky, barley being the material employed. Other grains are also malted and used alone for making whisky, but very seldom. Indian corn, for instance, may be the only grain used for making whisky, and rye is sometimes malted and used for making pure rye whisky. The great majority of American whiskies are made by a mixture of corn and unmalted or malted cereals.

Mashing

The rye and Indian corn are ground into a coarse meal, mixed in the mash tub with sufficient water to make a paste of proper density and the temperature is raised to 160, 170, and even to 180o, by which the starch is reduced to a paste. The mash is then cooled to below 140o and the barley malt added. The mash is then thoroughly mixed until the diastase of the barley malt converts starch of the Indian corn and rye into sugar. The mash is then cooled to the temperature of about 60 to 650 or even lower, and the yeast is added. The mash after the addition of yeast is often called wort. There are two methods of mashing, called the sour mash and the sweet mash. In the sour mash a portion of the products of the preceding fermentation is added to the mash, and the acidity of the mash is thereby increased. Sometimes the spent lees from the stills are also added to the new mash, so that it becomes quite acid. On the other hand, the sweet mash is made directly by using only the mashed unmalted cereals with the malt. Each of the processes has its claims for superiority, but upon the whole the old-fashioned sour-mash whisky is regarded as superior to sweet-mash whisky. Sweet-mash whisky is a more modern invention.

The times of fermentation are limited for the different mashes. For the sour mash the fermentation should extend over 48 hours, and for the sweet mash not over 72 hours. During fermentation the temperature of the mash rises, so that the fermentation may begin at 65 rising to 85, or even higher, before the fermentation is finished.

The product of the fernmetation is called beer. The old-fashioned method of separating the alcohol from the beer in-the United States is exactly the same as employed in Scotland, namely: in a Pot Still. Modern times have changed the character of the process of separating the alcohol from the beer. The alcohol is now usually separated from the beer by passing it through what is known as a beer still namely: a large cylindrical still with three departments.

When the distillation has proceeded to a certain extent in the first chamber, the contents of the top chamber are dropped into the second chamber, where again they come into contact with steam for a certain length of time. The contents of the middle chamber are then dropped into the bottom chamber into which the live steam is directly blown. When the still has once been charged it works continuously. The steam is blown into the bottom chamber and the vapors mix with the alcohol and pass to the middle chamber, boiling the mixture in the middle chamber; the volatile products of the middle chamber enter the top chamber and are driven over to the receiving tank. The stills are operated at such a rate that each time the spent beer is thrown off from the bottom chamber it is found to be practically free from alcohol. When the spent beer is thrown off from the bottom chamber the contents of the middle chamber are dropped into the bottom chamber; the contents of the top chamber dropped into the middle chamber, and the top chamber is filled with fresh beer. The objection to this process is, in the first place, that it is not a natural process of distillation, and in the second place, the live steam coming from an ordinary boiler gives it a bad flavor.

The distillate from the beer still is known as low wines. The low wines are dropped into a pot still, and it is then distilled either by building a fire underneath the still, the old fashioned, preferable way, or in modern times the distillation is carried on by means 20 of copper steam pipes in the bottom of the pot still. The distillate is collected in the receiving tank of the distillery under the supervision of the officials of the Internal Revenue, and are known in the distillery as high wines, usually having an alcoholic percentage of 60 by volume or more. When the high wines are collected they are drawn off by the gauger of the Revenue Service into casks, and before being placed in casks are diluted with pure water, to a proof of 50 percent alcoholic strength by volume. At the same time, under the law, the owner of the spirits is allowed to stamp upon the package the character of whisky he produces, namely: Rye Whisky, Bourbon Whisky, Corn Whisky, etc.

The last residues of the alcohol in the still are collected and thrown back into the beer for redistillation.