180 



GRAPE AND OTHER FRUIT JUICES 



using a better grade of apples, and following by 

 an immediate sterilization and bottling of the prod- 

 uct. The sterilization prevents fermentation and 

 the product is a pure apple juice. Orange juice is 

 put up in the same way. 



The manufacture of grape juice begins with the 

 picking of fully ripe grapes, of good quality. In 

 vineyards that are free from rot, "run of vine- 

 yard " grapes are used, but they are allowed to 

 remain on the vines and mature some weeks after 

 picking for commercial purposes has begun in 

 other vineyards. The grapes are taken to. the f ac- 



Fig. 266. storage of grape juice in fiTe-gallon carboys. 



tories in picking crates, holding forty to sixty 

 pounds each, and taken by an elevator to an upper 

 story and passed through a stemmer. The stems 

 contain a large proportion of tannin, and if kept 

 with the grapes will affect the flavor of the juice. 

 After being stemmed, the grapes are placed in 

 aluminum steam-heated kettles (Fig. 263), large 

 enough to hold fifteen hundred to two thousand 

 pounds each, and gently heated, not boiled. Care 

 is taken at this point, as in every application of 

 heat to the grape and its products, not to allow 

 too high temperature. If the temperature at any 

 time reaches the boiling point, a " burned taste " 

 is caused. The color comes from the pigment cells 

 of the skin, and can be varied by the amount of 

 heat and pressure used. At the first heating, not 

 more than 100° Fahr. is used. The seeds do not 

 lose their vitality in this heating process. The 

 minimum heat used in most factories in this stage 

 is 80° Fahr., although what is known as the " light 

 juice " is made in some factories by pressing before 

 any heat is applied, thus leaving the pigment cells 

 in the skin undisturbed. The heated mass of juice. 



pulp, seeds and skins is then placed in power 

 presses, usually hydraulic, where it is subjected to 

 great pressure. (Figs. 263, 264.) The juice again 

 goes to the heating kettles, where it is heated to 

 at least 180° Fahr., this being the lowest point of 

 sterilization. Heating above this point spoils flavor, 

 and it is the aim of the manufacturer to maintain 

 a steady temperature at this point until the stor- 

 age in the five-gallon carboys is completed and the 

 juice sealed in these receptacles. (Figs. 265, 266.) 

 Here it stands three months before being put into 

 the smaller bottles for the wholesale and retail trade. 



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- 

 fully decanted 

 and the sediment 

 dried out and 

 sold. It is largely 

 cream of tartar 

 and is used for 

 the preparation 

 of the purified or 

 The juice is resteril- 



commercial cream of tartar, 

 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. 



Uses 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 : 



