SUGAR AND ACID IN GRAPES DURING RIPENING. 
19 
Some interesting points are brought out by comparing the sugar 
and acid content from the date when all the berries were colored 
until fully ripe. The note " Berries, colored" is necessarily some- 
what arbitrary, because the coloring of these varieties is not at all 
alike; but we have used it in the general sense understood by the 
grape growers. These comparisons are presented in Table 2 : 
Table 2. — Increase of sugar and decrease of acid for certain periods, 1911. 
[Results in gram? per 100 cc.j 
SANDUSKY, OHIO. 
Variety and date. 
Condition of 
berries. 
Days 
elapsed. 
Total 
sugar. 
Gain of 
sugar. 
Total 
acid. 
Loss of 
acid. 
Ratio loss 
of acid to 
gain of 
sugar. 
Acid- 
sugar 
ratio in 
ripe fruit. 
Catawba: 
_4ug.27 
Berries, colored.. 
11.58 
19.45 
15.55 
21.17 
18.21 
24.46 
11.31 
17.36 
15.96 
22.67 
| 7.87 
| 6.62 
} 6.25 
| 6.05 
} 6.71 
/ 2.21 
\ .95 
/ 2.28 
\ 1.49 
/ .96 
\ .60 
/ 1.31 
\ .70 
J 2.11 
\ 1.34 
} 1.26 
} •» 
} .36 
} •« 
} •« 
1: 6.2 
1: 7.1 
1:17.4 
1: 9.9 
1: 8.7 
Oct. 4. 
Clinton: 
Aug. 23 
Wine-ripe 
Berries, colored.. 
38 
1:20.5 
Oct. 8 
Wine-ripe 
Berries, colored.. 
Wine-ripe 
Berries, colored.. 
46 
28' 
Delaware: 
Aug. 20 
Sept. 17 
1:40. 8 
Ives: 
Aug. 13 
1:24.8 
1:16.9 
Sept. 20 
Norton: 
Aug. 30 
Wine-ripe 
Berries, colored.. 
38 
Sept. 27 
Last sample i . . . 
28 
CHARLOTTESVILLE, VA. 
Concord: 
Aug. 12. 
Aug. 26. 
Cynthiana: 
Aug. 16. 
Sept. 15. 
Delaware: 
Aug. 5.. 
Aug. 26. 
Norton: 
Aug. 16. 
Sept. 19. 
Berries, colored. 
Wine-ripe 
Berries, colored. 
Wine-ripe 
Berries, colored. 
Wine-ripe 
Berries, colored. 
Wine-ripe 
3.06 
6.06 
9.36 
5.35 
0.98 
.53 
>.03 
.75 
1.32 
.65 
2.13 
.80 
} 0.45 
} 1.28 
} .« 
} 1.33 
1: 6.8 
1: 4.7 
1:13.9 
1: 4.02 
1:32.8 
1:28. 8 
1:39.7 
1:27.4 
1 Fruit was not fully ripe. 
The summary of the data given in Table 2, on changes in sugar and 
acid content of these varieties from the time the berries were colored 
until wine-ripe, show striking differences in the ratios, loss of acid to 
gain of sugar, and total acid to total sugar, at full ripeness. The 
greatest loss of acid to gain of sugar, hence the lowest ratio, is shown 
by Cynthiana and Norton at Charlottesville, and Catawba at San- 
dusky. The full data given in Table 1 show in detail the develop- 
ment of these varieties and that when ripe they gave an excellent 
juice for wine making. The ratio for these three varieties as to total 
acid and sugar when fully ripe show that the Catawba at Sandusky 
was not so well balanced in acid and sugar content as the Cynthiana 
