14 BULLETIN 656, U. S. DEPARTMENT OF AGRICULTURE. 



During tfie storage period the juice passes through a number of im- 

 portant changes. The hot juice when placed in the carboy has a 

 beautiful bright red color. As it cools it becomes turbid, and the color 

 takes on a brownish tint. The hot juice is full-bodied and has a 

 harsh acid taste. The stored juice has a reddish-brown color, is more 

 or less muddy, and has a pleasant taste and aroma. The loss in 

 acidity during storing is due chiefly to the crystallizing of acid salts 

 of tartaric acid. These salts are soluble to the extent of about 0.6 

 gram per 100 cubic centimeters in the stored juice; consequently any 

 amount of them contained in a juice in excess of 0.6 gram will be 

 precipitated. 



To determine the amount of material precipitated during storing, 

 the sediment contained in a carboy, which had been in storage about 

 one year and shipped from Chautauqua County, N. Y., to Chicago, 

 111., by express, was collected, dried, and weighed. It was found to 

 amount to 0.42 gram per 100 cubic centimeters of juice. 



With the precipitate a part of the tannin and coloring matter is 

 thrown down; consequently the resultant juice has a milder, more 

 pleasant, and decidedly less acid taste. 



Table 7 gives a comparison of the analyses of 22 juices, comprising 

 11 sets, half of which were analyzed at the time of storing and half 

 after 4 months' storage. 



The juices marked "Before" are the fresh juices taken while hot 

 from the sterilizing kettles, and those marked "After" are the same 

 juices after having been stored about 4 months. The differences in 

 composition are striking. In Table 8 the material given in Table 7 

 is condensed to show the maxima, minima, and averages of the two 

 sets of juices, and the average losses of the various ingredients during 

 the storing period. 



Table 8 shows a number of interesting facts. There is a substan- 

 tial decrease in solids during storing, about one-half of which is 

 accounted for by the precipitation of cream of tartar and earth 

 alkali tartrates. The other half is probably due to the precipita- 

 tion of pectin bodies and gums. There is no material difference 

 between the sugar contents of fresh and stored juice. With the 

 precipitation of cream of tartar other ingredients, such as tannin 

 and coloring matter, earth alkali tartrates, and gums and pectins, 

 come down. The precipitation of cream of tartar is also attended 

 by a definite decrease in nonsugar solids, total acids, total tartaric 

 acid, and the alkalinity of the ash. While the amounts of the con- 

 stituents vary in the case of the fresh juices, they seem to have 

 approached an equilibrium in the stored juices. This is especially 

 true of the cream of tartar. 



