THE USE OF PURE YEASTS IN WINE MAKING. 31 



the fresh sugared must did not represent the material in the vats with 

 accuracy. This is especially true of vats 1, 6, and 8, but in case of 

 vats 11,3, and 2 the fresh samples more nearly represent the material. 

 This is pointed out also in the preceding section. It is therefore 

 necessary to disregard the results of the analyses of the samples of 

 the fresh material and confine the discussion to the data furnished 

 by the samples of the young wine as drawn from the vats and the 

 samples of the wines from the casks. 



The discrepancy due to unequal sampling is perhaps greatest in 

 (lie case of the sugar content, but other constituents would doubt- 

 IMB be affected in a lesser degree. It is evident, from the analyses 

 of the yoim'j; win-s, that the average sugar content of the material 

 fermented for cask 64, yeasted, must have been about 18 percent, 

 while by the same reasoning that for cask 26, unyeasted, must 

 have contained quite 19 percent sugar. Eliminating, therefore, the 

 analyses which were made of the samples of the freshly sugared must, 

 a comparison of some interest may be made of the other data. 



The free run from the vat is the young wine which flows off without 

 pressure when the vat is tapped, and the press^wine is that which is 

 recovered from the pomace on the press. UsuanysoTrre time elapses 

 between these two operations as is noted in the history of each vat. 

 This element of time would of itself affect the condition of the wine as 

 to tli. ivhitive alcohol and sugar content, but would not affect the 

 final result in so far as alcohol content is concerned. But the change 

 in total acid content is decidedly important and raises a most serious 

 question as to the practice observed during this investigation. The 

 average acid found in the free run is 0.66 gram per 100 cc, which is 

 not too high for a young wine of the strength and body of the material 

 under consideration. But the press wine gave an average of 0.84 

 gram acid, which renders such a wine entirely too sour. 



While it is true that the proportion of press wine to free run is 

 usually quite small, yet with such a high acid content as here shown 

 its effect on the quality of the wine when mixed with the free run 

 i> serious. Note in this 'instance that the sample of young wine from 

 the cask taken after the wine was almost dry gave 0.739 gram of acid, 

 which is above the limit for good quality in such a wine. 



The variation of acid in the several vats only goes to show how 

 important it is to study this constituent in the fruit so as to deter- 

 mine how it is affected by the different soils and exposures, and by 

 the methods of culture. 



The comparison of acid content of free run and press wine in the 

 vats run to cask 26, unyeasted, are not so striking as for cask 64, 

 yeasted, but it must be noted that fermentation did not progress 

 to so great a degree of attenuation in the former, and further the acid 

 shown in the first sample from vats 1 , 6, and 8 is strikingly low. While 



