5. Mineral spirit is of theoretical interest, although it can be prepared in the chemical laboratory. if ethylene (Cal.) is conducted into sulphuric acid, ethylsulphuric acid is formed, which if diluted with water will split up into sulphuric acid and alco hol. Ethylene is a gas and is an ingredient of illuminating gas made from coal. It is also easily produced from acetylene (C,H,) by nas cent hydrogen, according to the formula + Ha = C4114 In accordance with the importance of these various kinds of raw material consumed in the large United States distilleries, we will first of all discuss the manufactures of liquors and spirits from starchy substances.
These raw materials are treated, as in the brewing industry, with malt (mostly barley malt, sometimes also rye and wheat malt) in such a way that the diastase of the malt con verts the starch into dextrin and sugar. But a distiller's malt differs in its properties from a brewer's malt. While the latter must impart its aroma and taste to the beer and only exert its diastatic power in a moderate degree, some of the starch remaining unchanged in the liquor, the former must be characterized by a maximum of diastatic power, to convert all the starch into fermentable sugar. Consequently the distiller prefers a malt from a small-ker neled barley, which has been killed at low tem peratures. The diastatic power is weakened by high temperatures and hence some distillers, who operate a malting plant in connection with the distillery, used only green malt, or at most, air-dried malt. The German distillers uni versally use green malt. In contradistinction to the brewer, the distiller prefers a malt made from a barley rich in nitrogenous matter, as this latter furnishes material for the formation of diastase and for the nourishment of the yeast. The malt used by distillers is that known as °long malt° (malted for 20 days) as distin guished from short malt" (malted for 7 days), used by the brewers. In making the long malt the grain is steeped until it has absorbed 40 to 45 per cent of water. It is then spread upon the malting floor for 20 days and kept at a temperature not above 63°. The development of mold or other bacteria is avoided by pre viously soaking the grain in diluted milk of lime. While the long malting causes a loss of starch, the gain of diastase far overbalances it. In mashing, the largest possible amount of starch must be converted into fermentable sugar (maltose) in order to obtain the highest yield of alcohol in the distillation. Under the most fav orable conditions 96 per cent of the starch in the mash material can be converted into maltose (the remaining 4 per cent is changed into dex trin), while in ordinary practice only about 80 to 81 per cent maltose is obtained and the re mainder is dextrin. After the maltose is decom
posed into carbonic acid and alcohol, the dextrin is gradually converted by the diastase into mal tose and then fermented. This can only be ac complished with vigorous yeast and proper treat ment in the fermenting rooms. On account of this uafter-effect" the diastase must be care fully protected from destruction by avoiding high mashing-off temperatures and the forma tion of an excess of lactic acid and particularly butyric acid, produced by certain bacteria at a temperature of to 122° F.
The mashing process varies according to the kind of product desired, the capacity of equip ment (large, or small, or very small, the latter requiring hand power for mashing in place of machinery), the amount and quality of the raw material and, oftentimes, on the fancy of the customers. Inasmuch as whisky is the main product of United States distilleries, we will discuss its preparation first of all.
The word °whisky° is of Celtic origin, for it apparently is an abbreviation of the word iusquebaugh" or quisgebeatha," which corre sponds to the Latin aqua (water of life), According to historical research the word aqua vita is a corruption, because the original wording for distilled spirit was aqua 'le vite (water from the grape vine). In mediaeval times the monks changed this earlier form to the one now in general use.
Although the same term is used in America, Ireland and Scotland, the product is different. The Irish and Scotch distilleries use almost exclusively kilned malt (only rarely, other cereals), while the American distilleries have an entirely different equipment and also their own characteristic development.
For the manufacture of whisky, especially corn and rye, sometimes also bran, wheat and kilned malt (6 to 15 per cent) are used. The best-known brands are: Bourbon whisky, in the manufacture of which corn is the main ingredient, with barley malt, or wheat malt and rye. According to the quality of the Bourbon, the materials vary as follows Ordinary Bourbon whisky is made from a mixture of 10 per cent malt; 10 per cent rye; and 80 per cent corn; Medium Bourbon from 12 per cent malt; 18 to 22 per cent rye, and 66 to 70 per cent corn; Good Bourbon from 15 per cent malt; 35 per cent rye; and 50 per cent corn.