282 INTERNATIONAL CONGRESS OF VITICULTURE 



The analyses of the wines show, by noting the sugar content, that fer- 

 mentation was completed promptly and that all the wines were apparently 

 sound and normal. The alcoholic strength is as high as experience has 

 found necessary for proper conservation of the wine in handling, except 

 for one sample of Concord and three samples of Ives. But these four excep- 

 tions show alcohol strength sufficient for ''ordinary" wine and we have been 

 able to hold such wines in wood for two years without material damage 

 from acetic fermentation. The Delaware samples show alcoholic strength 

 beyond all needs for preservation. These samples represent the complete 

 range of alcoholic strength of normal wines from American native grapes, 

 and cover a series of years, hence we conclude that our grapes will produce 

 sufficient alcohol. There is a legitimate demand for low grade wines such 

 as are produced from Concord and Ives and their blends. 



The total acid found in the dry wines of these experiments is of the 

 most vital importance as affecting their potable qualities. For the white 

 wines, Catawba, Delaware and lona, we know definitely the acid content of 

 the composite of must from which they were made. Therefore, the changes 

 which occurred in total acid are clearly shown by the figures given for total 

 acid found in fresh must and that for the wine at the last analysis. In every 

 sample of the white wines the acid has declined during the fermentation 

 and development of the wine. This amounts in one instance to .26 grams 

 per 100 c.c. (2.6 parts per mille) and though less for the other samples 

 there is a very sensible decrease. 



The acid content of the red wines, Clinton, Concord, Cynthiana, Ives and 

 Norton, do not show in every case a less quantity in the dry wine than the 

 young wine, but the exceptions are slight and apply only to Concord 1910, 

 Cynthiana 1911, Ives 1910 and Norton 1907. This exception is only apparent. 

 If we had an acid determination of every sample just as drawn from the vat, 

 it would show a higher acidity than shown by the analysis of the young wine 

 some weeks later. The acid determined in the fruit used, never shows the 

 actual acid of a red wine as drawn from the fermenting vat because the 

 process of fermentation extracts more perfectly the acid from the pulp than 

 can be done in pressing a fresh sample. 



To bring out the relation of total acid to alcohol in the dry wines, a ratio 

 is given for each analysis. This ratio is between total acid grams per 100 c.c. 

 and the volume per cent of alcohol. If the acid were reduced to percentage 

 the ratio would be still more striking, but as all the ratios are calculated on 

 the same basis it appears to fairly illustrate the point desired, to use the 

 ratio between gram weight of acid and volume per cent of alcohol per 100 c.c. 

 of the wine. Volume per cent of alcohol is invariably understood by wine 

 makers when speaking of the strength of their wines, and it is almost the 

 universal custom of chemists to report results on acid and sugar in grams 

 per 100 c.c., hence the reason for using, in this ratio, the determinations as 

 above expressed. 



In the white wines the acid-alcohol ratios show a very consistent relation 

 for the Catawba samples covering the four years of the experiments. The 

 sample for 1909 falls below the other years, and the sample for 1911 shows 

 the widest ratio. This latter crop was the best wine stock of Catawba we 

 have thus far examined. lona gives an acid-alcohol ratio similar to Catawba, 

 but Delaware shows a much wider ratio. In fact this grape is rather deficient 



