1154 
Journal of Agricultural Research 
Vol. XXX, No. 12 
which maximum sugar and minimum 
acid occur together: Colerain, Concord, 
Dakota, Elvira, Perkins, Rommel, and 
Ulster in 1923; Brilliant, Goethe, and 
Niagara in 1921; Martha in 1920; and 
Clinton, Eumelan, Lindley, Massasoit, 
and Wilder in 1919. There are fewer 
instances of occurrence of minimum 
sugar and maximum acid together: 
Canada, Dutchess, Lenoir, Merrimac, 
and Montefiore in 1922, Barry in 1921, 
and Noah in 1919 make up the list. It 
is clear that there is no hard and fast 
connection between acid and sugar con¬ 
tent in the grape, but rather a broadly 
general relationship. Conditions which 
favor the production of a crop of high 
sugar content also favor the reduction 
of acidity to a low level; conditions 
which depress the sugar production also 
tend to maintain acidity at a high level. 
This point will receive further discus¬ 
sion in a subsequent section. 
The maximum and minimum acid- 
sugar ratios occurring in each of 49 
varieties during the five years are tab¬ 
ulated in Table V. There is added for 
purposes of comparison an average 
acid-sugar ratio for each variety ob¬ 
tained by taking the mean of the yearly 
ratio for five years. By reason of the 
fact that the experimental period con¬ 
tained exceptionally unfavorable as 
well as unusually favorable crop years, 
the results probably present as wide 
variations as would be encountered at 
Vineland in a long series of years. 
Owing to the inclusion of the unfavor¬ 
able seasons and differences in the 
methods of sampling the fruit and ex¬ 
pressing the juice, and for perhaps 
other reasons, the average acid-sugar 
ratios differ materially from those re¬ 
ported by Alwood. The differences are 
all in the direction of a higher ratio of 
acid to sugar, as would be anticipated 
from the inclusion of two years char¬ 
acterized by low sugar and high acid 
content. 
The varieties studied may be grouped 
into three groups on the basis of their 
average acid-sugar ratios. These are 
a high acid group, consisting of juices 
whose proportion of acid to sugar is so 
high as to make them too sharp for 
beverage use; a balanced or medium 
group, in which the proportions are 
such as make the fresh juice agreeable 
and palatable; and a subacid group, in 
which the acid content is so low as to 
make the juice too insipidly sweet to 
be acceptable as a beverage. 
The definition of the exact limits of 
these groups is a matter of some diffi¬ 
culty. At present Concord is prac¬ 
tically the only generally available* 
commercial grape juice, and it is 
—Maximum and minimum 
acid-sugar ratio 
1:10.2 
_■ 1: 6.2 
_! 1:13.6 
... 1:10.9 
_i 1:10.2 
J 1:10.0 
_■ 1:11.9 
_ 1:16.7 
. 1: 8.2 
. 1:20.6 
. 1:23.7 
. 1: 7.5 
. 1:14.6 
1:25.8 
1:12.5 
1:14.9 
1:13.7 
1:14.4 
1:10.9 
1:21.6 
1 : 11.0 
1:10.6 
1:14.8 
1:12.0 
1:13.9 
1:15.4 
1:15.8 
1:22.5 
1:16.2 
1:15.5 
1:40.5 
1:31.4 
1:18.3 
1:22.4 
1:14.7 
1:10.8 
1:26.2 
1:19.8 
1:14.8 
1:15.6 
1:18.2 
1:24.7 
1:16.0 
1:32.8 
1:32.3 
1:19.2 
1:41.7 
1:11.7 
1:20.9 
1:23.6 
1:11.4 
1:37.1 
1:29.1 
1:34.7 
1:25.7 
1:23.3 
1:17.8 
1:27.6 
1:26.7 
1:25.5 
1:13.6 
1:29.4 
1:25.4 
1:15.7 
1: 8.9 
1:20.0 
1:15.7 
1:13.5 
1:12.2 
1:24.8 
1:24.8 
1:14.6 
1:29.4 
1: 9.5 
1:17.3 
1:12.7 
1:17.9 
1:16.7 
1:19.1 
1:20.2 
1:19.6 
1: 9.5 
1:25.6 
1:22.2 
1:30.9 
1:18.9 
1:19.7 
1:16.2 
1:14.5 
1:14.4 
1:19.7 
1:19.5 
1:17.4 
1:21.0 
1:20.2 
1:20.5- 
1:20.8 
1:20.7 
1:15.8 
logical to assume that its acid-sugar 
ratio is that which most people find 
agreeable and properly balanced, else 
it could not have attained its present 
popularity. It may therefore be made 
to serve as a starting point in a classi¬ 
fication of juices with respect to bev¬ 
erage quality. Hartmann and Tol- 
man (27) collected and analyzed 104 
hot-pressed commercial Concord grape 
juices representing the principal pro¬ 
ducing districts. Their analyses may 
be assumed to fairly represent the 
juices available in the markets. The 
average sugar content for the 104 
samples was 15.31 per cent, the ayerage 
total acidity calculated as tartaric was 
1.01 per cent, giving an acid-sugar ratio 
of 1:15.1. The maximum ratio found 
was 1:10.7, in a sample having 11.66 
per cent of sugar and 1.09 per cent acid. 
The minimum was 1:19 in a sample 
