Applied biology : an elementary textbook and laboratory guide / by Maurice A. Bigelow and Anna N. Bigelow.

  • Maurice Bigelow
Date:
1911
Catalogue details

Licence: In copyright

Credit: Applied biology : an elementary textbook and laboratory guide / by Maurice A. Bigelow and Anna N. Bigelow. Source: Wellcome Collection.

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    potatoes, are commonly used in producing alcoholic liquors, of which the chief varieties are mentioned below. Malt liquors (beer, ale, and porter) are made from malt, which is generally sprouted barley grains. This is ground in water, and allowed to ferment. Hops are added to give a bitter flavor. Such a fermented liquor consists chiefly of water, 1 to 8 per cent alcohol, and small quantities of other substances derived from the grains used. Wines are juices of grapes which have fermented and ])ro- duced G to 12 per cent of alcohol. Some wines are stronger because brandy or strong alcohol has been added when bottling. Distilled liquors (whisky, gin, brandy, rum) contain 30 to 50 per cent alcohol, and are made thus strong by distilling the fermented fluids (water with rye, corn, oats, or potatoes for gin and whisky; molasses in water for rum; wines for brandy). Various flavoring and coloring materials are added to the distilled liquors. They differ essentially only in color, flavor, and proportions of alcohol. Some of the sub- stances used to color and flavor are harmful, but are used in such small quantities that the alcohol is chiefly responsible for the physiological injury done by the distilled licpiors. Alcohol in a more or less pure state can be made by re- distilling and otherwise purifying any fluid in which fermen- tation has occurred. Since distilled liquors are nearly half alcohol, it is easily obtained from them. The grain alcohol of commerce is usually from 91 to 95 per cent pure; i.e., it contains 5 to 9 per cent of water. A si)ecial quality for scientific purposes is about 99 per cent pure, and is very ex- pensive to make. Commercial alcohol is usually called “ grain-alcohol,” or, in chemical terms, ethyl alcohol. Wood-alcohol, or methyl alcohol, is commonly made from wood. In all the discussions in this lesson, the word ‘‘ alcohol ” is used to mean grain or ethyl alcohol, for this is the characteristic constituent of