Page:The New International Encyclopædia 1st ed. v. 06.djvu/355

* DISTILLATION. 305 DISTILLED LIQUORS. been effected. If i» condenser is attached to the slill in such a niannei- that any liquid forming in it may lU)w buck into the still, and if the teni- ])eratuie in this condenser is kept constant, then the vapors passing out of it uncondensed are found to have tlie same relative composition, no matter what changes of composition are taking place in the distilling liquid. In most cases ex- amined (but not in mixtures of alcohol and water), the distillate thus obtained is found to boil exactly at the temperature at which the con- denser has been kept. See Chemistry: Uoillxg- Poi.NT: KvAPOR.Tiox : Distilled Liquors. Destrictive DisriLL.Tlo>-. This is quite dif- ferent from the process described above. For while that process is ])urc!y physical and in- volves no chemical change whatever, destructive distillation, as implied by the term, causes pro- found chemical changes in the materials sub- jected to it. Examples of destructive distillation arc: the heating of coal in gas-works at a red heat, when it resolves itself into coke, which is left in the retort, and coal-gas, naphtha, tar, etc., which distil over into suitable receivers: the treatment of coal at and below a red heat, when it yields much paraffin oil: and the distillation of wood in close vessels, at a red heat, when charcoal is left in the vessel, and wood-vinegar, wood-spirit, tar. etc.. pass over in vapor, and are condensed. See Tar; Coal-tar: Gas, Ilh- MixATixG: Par.ffix; Acetic Acid; Dippel's AxiMAL Oil; etc. DISTILLED LIQUORS, or Ardent Spirits. Alcoholic liquors manufactured by the process of distillation (q.v. ). They may be produced from fermented liquors or directly from the raw ma- terials, which must contain a large percentage either of sugar or of starch. An example of the first class is brandy, which is made by distilling wine. An example of spirit produced from sac- charine material is rum, which is made from molasses, while whisky, made from corn, rye, Iiarley, or other cereal, is an example of spirit made from a starchy material. The process of distillation may be so conducted as "to produce an alcoholic beverage or simply a 'raw spirit.' From the latter, by a process described below, is obtained the rectified spirit which is used as a basis in the manufacture of various alcoholic beverages. Rectified spirit is also employed in the arts, and from it. by a process of purifica- tion, is obtained the absolute ethyl alcohol of the chemist. See Alcohol. History. All the intoxicating drinks used in ancient times seem to have been the product of fermentation only. The art of distilling liquors is first mentioned by an Arabian physician of the tenth century, Albukassen by name, though the invention is attributed by some to the northern nations. The name a<jua tit(r. given to distilled spirits, shows what an estimate was put upon the discoverj' by early physicians and alchemists. ■One of them "declares this admir.able essence to be an emanation from divinity, an clement newly revealed to man. but hid from antiquity because the human race were then too young to need this beverage destined to revive the energies of modern decrepitude." Process of MAXfFACTi'RE. Spirits were first distilled from wine, but an endless variety of substances are now used in their manufacture. Alcohol, however, is the essential element in all spirits. It results from the decomposition o! sugar, which, by the process of fermentation, is resolved into carbonic acid and alcohol. Sugar is therefore tlie direct source of alcohol, and for this reason sweet vegetables and fruits may be converted into spirits. But stariHi is readily converted into sugar by means of the substance called diastase, which is found in malt and in germinating seeds generally. (See J?eer and 15rewi>g.) Hence, starchy as well as sweet vegetables may be used in the manufacture of spirits. In making distilled liquors, when the raw material is a fermented liquor, it is ready to be distilled without further ])reparation ; when it is a sugar, however, it must first be fer- mented and then distilled; when it is a starch, another initial ])rocess, to convert the starch into sugar, is necessary. il.si(ixG OR Preparation of the Wort. To saccharify the starch is the object of the initial ])rocess, technically known as 7naslii>ig. This process consists in mixing the raw grain, ])roperly ground, with malt and with water at a temperature of about 150° F. Barley, oats, and rye are the grains conunonly used. In Eng- land and the United States most distillers use a mixture of raw and malted grain,.in which the larger proportion is raw. The first mashing requires from one to four hours, during which time the mash is kept at a uniform temperature of 145° F. by successive additions of hot water. After this saccharine infusion, technically called itorf, has acquired its maximum density, as in- dicated by a saccharometer, it is drawn off. Fresh water is then poured upon the residue and allowed to stand to form a second wort. This is added to the first. A third wort, used to infuse a new mixture of grain, is sometimes made. In this method of direct mashing, nearly 10 per cent, of the grain is not decomposed. The waste may be reduced to 5 per cent, by heating the grain and water before the malt is added. In Germany, where potatoes are used for the manufacture of spirits, the potatoes are steamed before the malt is applied. This is advisable because potatoes contain a much smaller pro- portion of starch than the cereals. By steam- ing, the starch-cells are thoroughly broken and the starch reduced to a condition in which it is easily acted upon. Several different forms of apparatus have been devised for this purpose. In that of Henze. which is largely used, the steam is applied under pressure and the potatoes are reduced to a pulpy liquid, in which form they run into the mash-tub from an opening in the bottom of the apparatus. After this mass has cooled to the proper temperature, the malt is added and the wort formed as described above. Fermextatioj.'. This is effected by adding either brewei's or com])ressed yeast to the wort prepared as describeii above; or to a saccharine liquid obtained from molasses, beets, or other sugar-producing fruits or vegetables. Eight to ten parts of brewer's yeast are mixed with 1000 parts of grain mash, and with a larger propor- tion of yeast for jiotato mash. The chemical processes involved in fermentation, by which the sugar is resolved into carbon and alcohol, are discussed under Yeast and Fermentation. From three to nine days are consumed in fermentation. The priicess is continued until the density of the liquid ceases to lessen, as indicated by the saccharometer. Hydrofluoric acid is quite gen-