CONCORD GRAPE JUTCE. 13 



mentation. The cleaning of glass carboys can be more easily super- 

 vised, and the siphon can be placed to better advantage in them than 

 in jugs; the majority of factories therefore prefer the carboys. In 

 selecting the carboys or jugs care should be taken that the mouth 

 of the container has no defect and is as round as possible, so that the 

 cork may fit tightly. Furthermore, in selecting glass carboys, 

 vessels with perpendicular sides should be chosen in preference to 

 those with sloping sides, because the former permit better settling 

 of the lees or argols. To guard against possible fermentation through 

 defects in the mouth of the vessels, it is a good plan to pour a small 

 quantity of molten paraffin over the cork after it is in place, and 

 allow the paraffin to solidify before transferring the containers to 

 the vaults. The sealed vessels containing the sterile juice are 

 placed in the vaults and allowed to remain undisturbed for several 

 months, so that the juice may clarify and the excess of acid tartrates 

 be thrown out. To obtain the best precipitation, the temperatures 

 in the vaults should be kept as low as possible, i. e., as close to 32° F. 

 as can be maintained without danger of freezing. 



SIPHONING THE JUICE. 



As cream of tartar is least soluble at low temperatures, the juice 

 should be siphoned only during the winter months. At the close 

 of the precipitation period, comprising from 4 to 5 months, the corks 

 are drawn, and the clear juice siphoned into jugs. The siphon con- 

 sists of an aluminum tube bent U shape, over one end of which a 

 piece of rubber tubing of the desired length is drawn. The siphon 

 is placed in the vessel just out of reach of the sediment, and gentle 

 suction applied at the rubber end until the juice starts to flow. The 

 sediment remaining in the precipitation vessels is poured on several 

 thicknesses of burlap stretched on a frame, and the juice allowed to 

 drain. This juice, which is thick and muddy on account of small 

 crystals of cream of tartar and other material, is again treated in the 

 sterilizer, and poured into carboys in the same manner as the juice 

 proper, and again stored for precipitation and subsequent siphoning. 

 This juice, called "seconds," is mixed with the first siphoned juice. 

 The residue on the burlap, called " argols/' consists chiefly of acid 

 salts of tartaric acid. 



Experiments conducted by manufacturers for the purpose of 

 clarifying the juice during the precipitation period with the white 

 of egg and gelatin have met with little or no success. This failure 

 is to be expected, in consideration of the fact that heated grape 

 juice contains pectins and gummy substances, and that the juice 

 itself has a very marked viscosity. Of course, it is always possible 

 to remove the suspended matter by filtration, but this is a very 

 tedious operation, and it is doubtful whether it is worth the trouble. 



