II. NOTES ON THE USE OF PURE YEASTS IN WINE MAKING. 



INTRODUCTION. 



The use of pure yeast cultures in the fermentation of wines has 

 three main advantages: 



(1) To control the fermentation; that is, by using a sufficient 

 quant it y of a strong yeast culture poured onto the crushed pulp in the 



:(! win... or into the juice as it runs from the press in the case 

 of white \\ine, tn produce a dominant fermentation with the pure 

 yeasl and thereby suppress undesirable wild yeasts and other fer- 

 n) nt- \\ hi h injure the quality of the product. 



(2) T<> expedite the process of fermentation and thereby aid in 

 definite diivrti.. n and control of the fermentation room. 



(:*) If yeasts are properly selected they may be adapted to develop 

 the special qualities of a must and thereby enable the manufacturer 

 t<> maintain a 1> t ter standard of his products. 



Kather < \travagant claims have been made as to what may be 

 expected from the use of pure yeasts, but the consensus of informed 

 ^pinion \\arnmN only the statements just made. A pure yeast does 

 n<>t add to a must qualities which it did not originally possess, nor 

 one p<-Mhly hope to imitate particular wines by the use of yeasts 

 >elecied from those wines. On the other hand, pure yeast cultures 

 well selected for definite regions and for certain types of grapes, if 

 properly u-ed. will greatly aid in producing the best wine that the 

 di>triet i- capable of growing and in maintaining the standard of 

 quality. Nothing more can be claimed for them. Yet this is so 

 important that it is safe to predict that the use of pure yeasts will 

 ultimately he the rule. Their use is especially important for the 

 small grower who works for the highest quality and is willing to 

 develop \i\^ wines to maturity. 



AN EXPERIMENT ON THE CONTROL OF FERMENTATION. 



The details of an experiment conducted on a practical scale in the 

 season of 1908 is herein given for the purpose of bringing these defi- 

 nite data to the attention of wine growers. It is not possible at this 

 time to sav more about the quality of the product than is said in 

 the general note on the character of the young wine; but as regards 

 the control of fermentation and the facilitating of the work in the 

 vat room, the data presented are complete. The presentation of 

 these notes at this time should serve in a measure as a guide in the 



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