Wine, Grape

a beverage obtained as a result of the alcoholic fermentation of grape juice (must) or pulp (crushed grapes). Grapes that are ripe for production purposes or that have been sun-cured to the point of not more than 40 percent sugar content are used for grape wine. The chemical composition of grape wine is very complex. Besides water and ethyl alcohol (530-950 grams per liter [g/l ]), wine contains organic acids, principally tartaric acid (0.4-5.6 g/l ) and malic acid (up to 8 g/l ), and in lesser quantities citric, lactic, succinic, and acetic acids; sugars (glucose and fructose, 30-300 g/l ); tannins; pigment extracts; mineral substances; ferment; and vitamins (such as P, B₁ B₂, PP, B₆, and B₁₂).

Grape wines are distinguished for high caloric content: 1 l of dry wine yields about 2,500-3,300 joules (600-800 calories). Grape wines possess bactericidal properties: the addition of one part table wine to three parts water leads to destruction of the majority of bacteria, in particular, typhoid bacteria, cholera vibrios, and enteric rods (bacilli coli communi).

Red wines contain a great deal of vitamin P, which promotes the strengthening of the walls of blood vessels and better absorption of vitamin C. Grape wines are classified as varietal, produced from a single variety of grape, or blended, from a mixture of various varieties of grapes. Blended wines are obtained either by mixing wines from various grape varieties (coupage) or by combining grapes of various varieties even before processing (cépage). Sometimes plantings of different grape varieties are intermingled, to achieve natural cépage. In producing varietal wines, no more than 15 percent of other varieties may be used in coupage or cépage.

Still wines, which contain no surplus of carbon dioxide gas, are distinguished from those that contain carbon dioxide gas. Still wines are classified by content into table wines (dry and semisweet), fortified (strong and dessert wines), and aromatized. White and red table wines are obtained without the addition of alcohol; they are the product of complete fermentation of natural grape juice. Dry table wines contain from 9 to 14 percent (by volume) alcohol of natural fermentation and not more than 0.3 percent sugar; semisweet table wines contain 9 to 12 percent alcohol (volume) and 3 to 8 percent of unfermented sugar. The following Soviet table wines are especially famous: among the whites, Sil’vaner, Risling, Rkatsiteli, and Kakhetinskoe; and among the reds, Kaberne and Saperavi.

In producing fortified grape wines, addition of distilled alcohol is permitted. Fortified grape wines contain 17 to 20 percent alcohol (by volume), including not less than 3 percent alcohol (by volume) of natural fermentation and 1 to 14 percent sugar. In preparing fortified wines (such as port, Madeira, sherry, and Marsala), at least 5 percent of the sugar must be fermented, since 1 percent of the sugar yields 0.6 percent alcohol (by volume). Dessert grape wines contain 12 to 17 percent alcohol (by volume). Of this amount, not less than 1.2 percent alcohol (6y volume) must come from natural fermentation; that is, it is necessary to ferment not less than 2 percent of the sugar. Dessert wines (such as Cahors wines, Malaga, Tokay, Pinot Gris, muscat, muscatel, and sweet white, red, and rose wines) are classified according to sugar content as semisweet (5-12 percent sugar and 14-16 percent alcohol), sweet (14-20 percent sugar and 15-17 percent alcohol), and liqueur (21-35 percent sugar and 12-17 percent alcohol). Aromatized wines (vermouth) are prepared by adding distilled alcohol, saccharose, and also essences of various plants. The alcohol content is 16-18 percent by volume, with a sugar content of 6-16 percent.

Wines containing carbon dioxide gas are divided into those naturally carbonated by fermentation in hermetically sealed Vessels under pressure (for example, champagne and natural semisweet sparkling wines), and effervescent wines, artificially carbonated with carbon dioxide gas.

Grape wines are classified by color as white, rose, and red. They are divided by quality into ordinary, label, and collectors’ wines. Ordinary wines are those released without aging, in their first year of life; label wines are aged, high-quality wines produced in various wine-producing regions or microregions by special technology. Dry table label wines should be aged not less than 1.5 years, reckoning from January 1 following the harvest year (except for wines of the Kakhetinskoe type, whose aging period is not less than one year); fortified and dessert wines should be aged not less than two years (except for wines of muscat grape varieties, which are aged not less than 1.5 years). Collectors’ grape wines are label wines of especially high quality, which, after completing a period of aging in barrels, vats, or tanks, are additionally aged not less than two years in bottles. A total of more than 600 denominations of grape wines are produced in the USSR.

Wine poured into bottles should be kept in a dry, cool (8°-16° C) place; table wines and champagne must be stored in a horizontal position. Every wine has its optimal life span; for white table wines and champagne, it is 3-5 years; red table wine, 5-10 years; dessert wines, 18-20 years; and liqueurs and fortified wines, 100 years or more.