Page:The New International Encyclopædia 1st ed. v. 20.djvu/670

* WINE. 572 WINE. cent, of alcohol and is slow and uncertain above 12.5 per cent. It converts the sugars largely into alcohol and carbon dioxide, theoretically thus: Glucose or^ Aloohol-I- ^'^'■''^'^" levulose '" dioxide CcH,A=2C,H,0+2CO, the alcohol being 51.11 per cent, of the sugar fermented. In practice, however, only about 48.5 per cent, of alcohol is formed, the deficiency be- ing represented niainlj- by glycerin (from 6 to 14 parts by weight to 100 of alcohol), higher alcohols, succinic and acetic acids and ethereal salts, upon the nature and quantit_y of which last the flavor of wine largely depends. Since the development of sugar is largely dependent upon temperature, the wines of northern cli- mates are uniformly poorer in alcohol than those of the south. The alcohol content of unfortified wines known to be pure varies from 2^^ to 18 per CMit. by volume; that of glycerol, from 0.2 to 1.4 grams per 100 cubic centimeters. A relatively high ratio of glycerol to alcohol is thought to indicate a superior wine, and in Europe a content of 7 to 14 parts glycerol to alcohol is desired, but. since many wines contain less than 7, the tendency is to lower the mini- mum to G. .Judging from the few complete analyses, American wines seem to fall below European in this ingredient. Cream of tartar, to which the acidity of must is largely due, may range from 0.5 to 1.5 per cent. As grapes mature their relative acidity diminishes with the increase of sugar: as the must matures its aljsolute acidity decreases be- cause of the deposition of cream of tartar, which is insoluble in alcohol. The acid of wines, which rarely contains less than 0.4 gram nor more than 1.5 grams, calculated as tartaric acid, per 100 cubic centimeters, is often diminished during ageing by the action of microorganisms as well as by the separation of the cream of tartar. It may, however, be increased by concentration and by the formation of lactie and succinic acids. Its content is usually in inverse ratio to tlie con- tent of alcohol ; thus dry, northern wines are less alcoholic but more acid and aromatic than southern ones. Volatile acids are always formed during fermentation, but excess indicates care- lessness in management. In northern wines they are limited to .12 and .10 grams per 100 cubic centimeters respectively, in white and red wines. Coloring matter is found in the skins, w^hich, like the stems and seed coats, contain tannin. Hence, the closer the crushing, and. in red-wine making, the longer the inunersion of these parts in the must, the higher the percentage of tannin in the expressed juice. Tannin is not present in the 'first run.' and, like coloring matter, is de- ficient in the juice of stemmed grapes quickly pressed. -Allniminoids, of which from 0.25 to 0.0 per cent, is found in must, are somewhat decreased by fermentation. Their deficiency precludes complete fermentation; their excess is thought to inter- fere with the preservation of the wine; but their offices are not fully inderstood. A'arying some- what with the varieties, the solids of wliite wine (e.xeept sugar) vary from l.fi to 2.5 grams per 100 cubic centimeters: those of red wine, 1.8 to ,3.7: pure German reds reaching tlie minimum and Californinn rarely less than 2.4 grams. Wines with an ash content of less tb:in 14 grams per 100 cubic centimeters are suspected, as are also those containing a high sodium chlo- ride or potassimu sulphate percentage and a minimum ash. The ratio of ash to extract is usually about 1 to 10, and the percentage of ash depends largel}' upon the composition of the wine in other respects; for instance, a plastered wdne will necessarily contain a high ash, and a new wine more than an old. The separation of cream of tartar diminishes the ash content and the neutralization of excessive aciditv increases it. The Municipal Laboratorv' of Paris considers red and white wines to be fortified when their alcohol content exceeds 4.5 and 0.5 times, re- spectively, the weight of their extracts. It also considers wine to be diluted with water when the percentage of alcohol by volume ('natural' alcohol in the case of fortified wines), plus the weight of total acids in grams (expressed as sul- phuric acid — H.SOj), is less than 12.5 per liter. The figure obtained by deducting the sum of the glycerol, ash, and fixed acids from the sugar- free solids is usually between 0.3 and 0.6 gram per 100 cubic centimeters, a figure of great im- portance in wines of low extract content, since it helps to determine whether addition has been made to increase the percentage of extract to the minimum limit. A high undetermined extract should accompany a high percentage of alcohol and a low acid content. The composition outlined above is possible only with wines made from grapes adapted to their climate and soil and grown in a favorable year. When the must of a particular vintage is not normal, as often happens, additions of sugar (chaptalizing), of acid, or water (gallizing) are permitted in many countries to make it nor- mal : bvit such treatment is liable to abuse. When added so as to increase the output the practice is fraudulent. The fermentation of the pomace with sugar water, or of the liquid obtained by extracting pomace with sugar water (peotizing), is popular in France, the cheap wine-like beverage (piquette) being a legitimate product when sold under its own name. Cheap wines are often made from raisins and other dried fruits, sugar .and glucose. The addition of preservatives to wine is not permissible. The use of sulphur for bleaching a dark-colored white wine or to check improper fermentation is fraudulent, though sul- phur is widely used for cleansing the casks prior to their use in fermenting. Foreign coloring matters in red wine should not be employed; the skins should supply suflicient color, ilisrejire- sentntion as to variety of wine and place of pro- duction is the most couunon fraud practiced with supposed medium and liigh-grado wines. Blending, which is allowable and es.senlial in many cases, is subject to abuse in some celebrated wine regions, especially near Bordeaux, where foreign wines are largely used to increase the volume and cheapen the product. DlKTETtC .xn JlEniCINAI, V.r,UE OF WiN'ns. .s a general rule, the use of wine even in moder- ate quantitiefi is not necessary for young or adult persons in good health and liviiisr under normal conditions. In elderly individuals and those en- gaged in sedentary occu)iaf ions, the taking of small quantities of carefully chosen wine with the meals is not only permissible, but oftentimes distinctly beneficial. Wines may bo roughly di-