284 INTERNATIONAL CONGRESS OF VITICULTURE 



for white wines and 1:17.7 for red wines. On the whole these ratios of 

 French wines conform closely with what the average taste of wine users 

 demands. 



As a tentative proposition for dry still wines, I suggest as minimum 

 and maximum ratios 1:16.0 to 1:20.0. A full bodied heavy wine will naturally 

 carry the narrower acid-alcohol ratio while a light thin wine should have 

 the wider ratio. Judged on the proposition advanced above, the pure dry 

 wines we have made from American native grapes are not as a whole ex- 

 cessively acid. Therefore their amelioration ought not to be a difficult mat- 

 ter. The use of a reasonable amount of sugar solution to accomplish 

 amelioration when needed is warranted, but should be allowed, only under 

 control of some adequate authority in order to protect the legitimate producer 

 as well as the user. 



As a final comparison there is given the ratio between the original sugar 

 determined in the must and the alcohol determined at the last analysis of 

 the wine. This sugar-alcohol ratio of the wine is most interesting. It shows 

 that in most instances where a variety has been used for wine in different 

 years we have produced an almost identical quantity of alcohol for the 

 sugar found in the original must. The value of such a comparison in these 

 experiments is that it furnishes a check upon the accuracy and similarity of 

 technic observed in making and handling the wines. 



The exceptions to be noted in regard to the uniformity of this ratio are, 

 in case of Concords, Ives and Norton where a few aberrations appear. The 

 most striking variant is the Ives wine for 1909. No explanation of these 

 variations can be offered at this time. It is noticeable that the white wines 

 ferment drier than the red and give a slightly higher alcohol factor. 



The theoretical alcohol to be derived is found if the percent of sugar in 

 the must be multiplied by .598. The result of this calculation is the alcohol 

 volume per cent which should be produced in the wine. Our experiments 

 show that this factor cannot be exactly relied upon in practice. 



