CHAPTER V ALCOHOLIC BEVERAGES' Alcoholic beverages may be divided into two classes: (A) Fermented beverages and (B) Distilled beverages. The fermented beverages are sub-divided into two classes: 1. Those fermented without the addition of yeast. 2. Those fermented with the addition of yeast (Malt Liquors). A. FERMENTED BEVERAGES 1. Those beverages fermented without the addition of yeast are wine, cider, perry and similar beverages made by the natural fermentation of saccharine fruit juices, and a few beverages made by the natural fermentation of starchy solutions. Malt Liquors 2. Those beverages fermented with the addition of yeast include ale, beer, lager beer, porter and stout. History The manufacture of fermented liquors from grains is of very ancient origin, at least 2,000 years old. The process was known to the ancient Egyptians, Romans, Spaniards, and Germans, and was introduced by the latter into Great Britain and later 1 Beverages, both non-intoxicating and intoxicating, are classified under the general head of foods, and are therefore here discussed. into the United States. The knowledge of alcohol as a constituent of wine or beer was not known until the time of Marcus Graccus, who wrote in the twelfth or thirteenth century of the distillation from these beverages,1 of a substance called "aqua ardens." Information on a process for making beer seems to be nearly as old as that for making wine; but the Greeks and Romans regarded beer as a barbarian drink. Beverages brewed from such cereals as rice, millet, rye and barley are common in Africa, Russia, Japan and China. Chemistry of Beer Manufacture Malt liquors, although primarily made from malt, or "sprouted barley," may be made from the infusion of wheat, rye, oats, rice, corn (maize), with the addition of other substances such as beet roots, potatoes, sugar, molasses, glucose, etc., in fact all that is necessary is to have a starchy or saccharine substance capable of fermentation with yeast. Yeast (Enzymes) Our knowledge of fermentation was very imperfect until 1857 when Pasteur showed that yeast consisted of living organisms capable of growth and multiplication. In 1897 Buchner2 submitted. yeast to great pressure and isolated from it a nitrogenous substance, enzymic in character, which he called "zymase." This body is formed continually in the yeast cell, and decomposes the sugar which has diffused into the cell. This yeast juice causes solutions of cane sugar, glucose, levulose and maltose to ferment with the production of carbon dioxide and alcohol; but it has no action on milk sugar and mannose. This enzyme probably cannot be produced except by the action of the living protoplasm. This seems to point to the theory that there are two classes of ferments which bring about the changes called fermentation; viz., soluble 'Daniel, P. Sci. Mo. Vol. 82, p. 567. 2 Ber. d. D. Chem. Ges., 1897. unorganized ferments like zymase, and insoluble organized ferments, which are minute vegetable growths. Chemical reagents bring about reactions which are analogous to the changes brought about by the unorganized ferments, as for instance, boiling with dilute acid perfectly imitates the hydrolytic action of diastase on starch. (See also p. 15.) Lavoisier was the first chemist to study fermentation from a quantitative standpoint. Gay-Lussac first proposed in 1815 the reaction with which we are familiar, representing the chemical change which takes place during alcoholic fermentation: C6H12O6=2CO2+2C2H5OH The most important of the soluble unorganized ferments, as noted above, is "diastase." This is formed from the abluminoids of such cereals as barley, especially during the process of germination. Its action on the barley is to change the starch of the grain to dextrin, maltose and dextrose.1 Thus: C6H10O5+H2O=C6H12O6 Invertase is another soluble unorganized ferment and is capable of converting cane sugar or sucrose into invert sugar, thus: C12H22O11+H2O=2C6H12O6 This enzyme is contained in yeast and can be readily extracted from it, by filtration and precipitation with alcohol. The organized ferments or vegetable growths are divided into molds, yeasts, and bacteria.2 The most important fermentation industries are dependent mainly on the action of yeasts and bacteria. On the phenomena of alcoholic fermentation are based the baking, malt liquor, wine, and spirit industries. On acetic fermentation depends the vinegar industry (see p. 235) and the 1 Industrial Org. Chem. Sadtler, p 203. 2 Sadtler, loc. cit. cheese and other milk industries depend on lactic and butyric fermentations. (See. p. 414.) Beer Manufacture The starting point in the making of beer is to prepare the malt. For this purpose barley is steeped in water at 60° F. for two or three days, then taken out of the tub and piled on the floor of the malthouse to "couch" or heat. As the germination of the grain proceeds the layers are spread thinner and thinner, and at the end of about ten days the tiny rootlets have started, and the germ has grown to be about two-thirds the length of the grain. The product is then dried in a kiln at a gradually increasing temperature, sometimes as high as 180° F. Drying stops the fermentation, and the product, after being sifted, to free it from rootlets and germs, is put on the market as malt. In the malting process the starch of the grain, by the action of the ferment "diastase," has been changed to soluble maltose, dextrin, etc. Malt is used for making beer, malt extract, sirups and sugars, and for various other industrial purposes. In making beer the malt is ground and heated with water to extract the soluble constituents. This process is called mashing, and the extract obtained is known as the wort. Other grains are often introduced into the wort, as there is usually enough diastase in the malt to change to sugar more starch than that which exists in the malt. itself. The clear wort is boiled with hops, cooled rapidly, and run into vats for fermentation with yeast. After this process has proceeded for perhaps eight days, the liquid is drawn off into casks, which are stored in caves or cellars where the after-fermentation takes place. Some of the well-known beers that were formerly on the market in this country, and are in common use abroad are; Schenk, containing 3.36 per cent. of alcohol by weight; Lager, 3.93; Bock, 4.69; Weiss, 2.73; Munich Hofbrau, 2.95; Munich Boch, 3.25; Pilsner, 2.75; Porter, 4.70; Ale, 4.75. Constitutional Prohibition The Eighteenth Amendment to the Constitution of the United States reads: "The manufacture, sale or transportation of intoxicating liquors within, the importation thereof, into or the exportation thereof from the United States and all territory subject to the jurisdiction thereof for beverage purposes, is hereby prohibited." The Volstead Act limits the amount of alcohol that may be present in beverages, to one half of one per cent. Physicians are allowed to prescribe limited amounts of alcoholic beverages, and they may be sold under certain stringent regulations for medicinal use. Alcohol may be withdrawn from the Government warehouses for use in the Arts. There are upon the market an endless variety of so called "near-beers," which are free from alcohol, and have somewhat the taste of beer. These are carbonated, and frequently contain an extract of soap-bark, so that they foam readily when served. Action of Beer on the System Aside from the direct action of the alcohol on the system (see p. 150) the hop extract in beer causes it to induce drowsiness, and it also acts as a tonic in some cases. It causes biliousness in persons of weak digestion, and has a tendency to act as a fat producer, so that if used in excess it produces obesity and greatly distends the stomach. On account of the extractives present, beer contains more nourishment than other alcoholic beverages. It does not follow from this however that the beer is to be recommended as an economical food. B. DISTILLED BEVERAGES The common distilled liquors are whiskey, rum, gin and brandy. (See p. 130, 145, 265.) Besides these there are numerous |