CHEMICAL COMPOSITION OF AMERICAN GRAPES. 15 



DISCUSSION OF ANALYTICAL RESULTS. 



1911 SAMPLES. 



The remarkably high quality of the samples of the standard varie- 

 ties collected in 1911, examined at Sandusky and Charlottesville, is 

 worthy of emphasis, because of the statement so frequently made in 

 the past that our native grapes are unfit for wines or other by-products 

 without a large addition of sugar or sugar solution. It may be 

 noted that 28 samples of Catawba from the northern Ohio district 

 average 20.24 grams of sugar and 0.709 gram of acid in 100 cc, or an 

 acid-sugar ratio of 1 to 28.6. Such fruit properly handled does not 

 require any amelioration for unfermented juice or for wine. In this 

 connection it is important to note that this is the lowest acid content 

 found for Catawba but not the highest sugar content. The crop of 

 1911 was exceptionally well balanced as to the ratio of acid and 

 sugar content in most varieties. 



Clinton for five samples examined shows 21.62 grams of sugar and 

 1.173 grams of acid in 100 cc, or an acid-sugar ratio of 1 to 18.4. 

 This is the highest sugar content recorded for Clinton, and also the 

 widest acid-sugar ratio. 



The Concord samples show remarkable acid-sugar ratios. For 

 both northern Ohio and Virginia samples this is about 1 to 34, and 

 23 Concord samples collected from other northern points outside of 

 Ohio show an acid-sugar ratio of 1 to 25.9. 



Cynthiana and Norton are similar varieties in appearance, growth, 

 and general character of fruit but show differences in composition 

 which are quite important. Cynthiana in Virginia gives 21.23 grams 

 of sugar and 0.767 gram of acid in 100 cc, or an acid-sugar. ratio 

 of 1 to 27.7, while Norton, with 21.49 grams of sugar and 0.867 gram 

 of acid in 100 cc of juice, shows an acid-sugar ratio of 1 to 24.8. From 

 the well-known character of the juice of these grapes, and the large 

 precipitation of cream of tartar which will occur with correct treat- 

 ment, the acid content is rather low for producing a pleasant, 

 sprightly food product. 



1913 SAMPLES. 



The samples collected in North Carolina were of varieties of the 

 Vitis rotundifolia species commonly called muscadine grapes. Since 

 these are grown quite extensively for the manufacture of wine, it 

 was desirable to obtain information as to their composition. Their 

 acid content is in most cases favorable to wine making. Ten samples 

 were examined for sucrose with the result that this form of sugar was 

 found in appreciable quantity. The results here given are on the 

 expressed juice. 



The New Jersey samples introduce a few names not heretofore 

 recorded in this work. None of the samples from this district show 

 a high sugar content; in fact they are mostly low in sugar when 



