20 BULLETIN 335, U. S. DEPARTMENT OF AGRICULTURE. 



and Norton at Charlottesville. The analyses of this Catawba crop, 

 which was inferior to some others of the Sandusky district, show its 

 high value for wine manufacture. 



The extremely high ratio of gain in sugar to loss in acid shown by 

 Delaware and the very wide ratio of total acid to sugar content in this 

 variety bears out the previous statement that this grape is low in 

 acid for commercial purposes. This grape would make a wine with 

 an acid-alcohol ratio when finished of about 1 to 26, whereas 1 to 20 

 is about the right ratio for a potable wine of this class. 



CROP OF 1912. 



The work on development of acid and sugar content in grapes was 

 confined during 1912 to two varieties, Concord and Catawba, at 

 Sandusky, and also to two varieties, Delaware and Concord, at Char- 

 lottesville. The full data on the juice samples are given in Table 1. 

 A much more complete study of the composition of the whole fruit 

 was undertaken than heretofore, with results as given in Table 6. 

 This later work consisted of fairly complete organic and ash anal- 

 yses of the whole fruit, whereas the work done heretofore was con- 

 fined to the expressed juice. 



All of the fruit used in 1912 was taken from vines reserved for this 

 work and the sampling was done in every instance by the same per- 

 sons as in 1911. 



The work at Sandusky was begun several weeks later than in 1911, 

 but the first samples were taken before the fruit was fully colored. 

 The crop was late and Catawba developed unevenly and was not in 

 prime condition at any time. In fact the Catawba crop used for 

 this work failed to mature properly and did not fully ripen; 1912 

 was a poor crop year for all the late grapes in northern Ohio. At 

 Charlottesville the fruit ripened promptly and was in excellent 

 condition. 



A comparison of the sugar and the acid elements in the composi- 

 tion of Catawba for the two years, 1911 and 1912, are presented in 

 Table 3. The results for 1912 are taken from the date when the 

 fruit was noted as showing pink color instead of fully colored, as in 

 1911. The coloring of this fruit in different years varies greatly, 

 but the sugar and acid content indicates comparatively the same 

 stage of ripeness when the first samples used in the comparison were 

 taken. As the dates of sampling for the two years are not the same, 

 two dates are given for each line in the date column at the left of the 

 table. The first date in each case is the date of sampling for 1911 

 and the second for 1912. The comparison does not include all the 

 analyses for 1911, but does give those which mark the several stages 

 of maturity to the date when the crop was fully ripe, and the results 

 are given for 1912 until the fruit was destroyed by frost. 



