It is generally figured that ele ven to thirteen pounds of grapes are used in mak ing one gallon of unfermented grape juice. The amount varies with the season, the soil of the vineyard, the quality and ripe ness of the grape and also with the variety.
By-products.
A sediment is deposited in the storage carboys. The juice is care f ully decanted and the sediment dried out and sold. It is largely cream of tartar and is used for the preparation of the purified or commercial cream of tartar. The juice is resteril ized, and rebottled in the pint, quart, or gallon bottle of commerce ; it is then labeled, packed and shipped.
Pomace.—Another by-product is pomace, which has a fertilizer value but is more largely sold to distilleries, where from it is made a grape brandy containing a high grade of alcohol. The use of the pomace from which to make denatured alcohol is anticipated as an enterprise which legislation may make possible. This pomace is composed of the skins, pulp and seeds left after the juice is expressed.
Lees of grape juice.
The use of grape juice as a beverage is becoming very common, as the sale of 1,250,000 gallons during the current year will indicate. It has a very important use, also, in the hospital and sick room as a tonic and nutrient. There is every reason to expect greater popularity for it. The juice, subjected to chemical analysis, shows the following composition: The food value of the grape is greater than that of any other fruit in popular consumption. This
superior nutrient quality is due to a larger content of sugar, gluten, mineral salts and fruit acids, together with a lesser quantity of water, than so great a content of nutrients generally affords, especially in the fruits. Grape-sugar (of the grape) is the chief nutritive constituent. The particular advantage which grape-sugar possesess over all other types of sugar is the ease of its assimilation. Grape-sugar, unlike other sugars, is naturally in the state to which all other carbohydrates must be reduced by preliminary digestion before they are ready to be absorbed by the system. This physical property rests on the fact that its constituent elements are in looser chemical combination, and therefore the greater part of the sugar passes into the circulation unchanged. The grape is unusually rich in albuminoids. It also contains a very fair percentage of vegetable fats.
Literature.
Wm. T. Brannt, A Practical Treatise on the Manufacture of Vinegar, etc., Part II (Manufacture of Cider, Fruit Wines, etc.); A. Hausner, The Manu facture of Preserved Foods and Sweetened Meats ; Bioletti and del Piaz, Preservation of Unfermented Grape Juice, Bulletin No. 130, California Experi ment Station ; Bioletti, A New Method of Making Dry Red Wine, Bulletin No. 177, and The Manufac ture of Dry Wines in Hot Countries, Bulletin No. 167, Calif. Exp. Sta.; Husmann, Home Manufacture and Use of Unfermented Grape Juice, Farmers' Bulletin No. 175, United States Dept. Agric.