It is important, in selecting grapes for making an unfermented beverage, to have them reasonably low in acid and with a comparatively high content of sugar. Well-ripened grapes, grown in the regions mentioned, have approximately the following average composition: total solids in the expressed juice, 22 percent; solids not sugar, 2 percent; invert sugar, 19 percent; total acidity, reckoned as tartaric, 0.65 percent. There are many wide differences from these mean data, according to the season of the year and the character of the grape. As the grapes grow riper the acidity tends to decrease and the sugar content rises. The mean composition of different varieties of grapes, as reported by Professor W. B. Alwood, Bureau of Chemistry, is as follows:

Table 1

Average Composition of 8 Important Native American Grapes Results in grams per 100 cubic centimeters.)'

Variety

No. of samples

Specific gravity of juice

Total solids calculated

Sugar-free solids calculated

Total sugar as reducing

Total acid as tartaric

Acid-sugar ratio.

Catawba....................

221

1.0858

22.30

2.42

19.88

0.928

1:22.5

Clinton.......................

25

1.0896

23.3I

3.51

19.80

1.464

1:14.4

Concord................................

127

1.0754

10.57

2.48

17.12

0.650

1:27.6

Cynthiana..................

5

1.0942

24.51

4.21

20.30

1.108

1:19.8

Delaware...................

53

1. 0993

25.85

2.39

23.37

0.646

1:37.7

Iona............................

61

1.0877

22.79

2.30

20.50

0.753

1:27.7

Ives............................

100

1.0704

18.27

2.79

15.45

0.693

1:22.7

Norton.......................

50

1.0987

22.50

3.24

19.24

1.080

1:17.8

The above table is made up of examination of a large number of samples of the leading varieties of grapes, extending over a period of time from 1908 to 1911 inclusive. The districts represented are almost entirely those of Northern Ohio and Virginia. The data, therefore, are truly representative of the normal composition of the varieties mentioned. Inasmuch as the Concord grape is the one which is chiefly used for making grape juice, it will be interesting to compare commercial grape juices with the grapes from which they are chiefly made.

Composition of Samples of Grape Juice Bought on the Open Market

Total solids

Sugars

Solids not sugar

Cane sugar (sucrose)

Royal Purple grape juice................

16.22

14.48

Red Wing grape juice................................

19.27

16.70

2.57

0.76

Grape juice.....................................

18.83

17.78

1.05

1.35

Monticello grape juice....................

20.64

18.26

Grape juice......................................

17.79

14.31

In the examination of commercial samples of grape juice I have not found any glucose, saccharin, salicylic acid, benzoic acid, borax, sulphurous acid, or any of their compounds. This fact shows that the use of preservatives in commercial grape juices is no longer practised. Occasionally we find added cane sugar, usually not to exceed about 2 percent. The most striking fact, however, is that the total sugars in the grape juices of commerce are not as high as are found in the grapes of good quality, as determined by the analyses of Alwood. This discrepancy may be due to the fact that grapes of less desirable quality are used. I should hate to hint that water is added in the process of manufacture. There is no evidence that I know of this practice, save the variation between the amount of sugar in the grapes and the amount which is found in the commercial samples.