26+ PRESENT POSITION OF 



influence of injurious micro-organisms. It is stated that wines 

 fermented with pure yeast are superior as regards odour 

 and taste, clarification and stability, to wines fermented with 

 ordinary impure yeast and from the same district. Dr. Schnell 

 obtained a like result from his experiments. 



With regard to the fermentation of sparkling wines 

 (champagne) Wortmann states : " In this field, especially, the 

 advantages offered by a fermentation with selected pure 

 yeast are evident. For, in order to re-start the fermentation 

 of these wines, the method hitherto adopted was almost more 

 dependent upon chance than in other cases, for one had to be 

 content with yeasts the properties of which often were very 

 undesirable. But especially in the case of the fermentation 

 in bottle, the yeast should possess certain properties, namely, 

 in the first place, that of having a high fermentative power, 

 in order that they may also be able to effect the completion 

 of the fermentation in the presence of the high proportion 

 of alcohol, and under the great pressure of the carbonic acid 

 gas ; in the second place, the yeasts must be heavy, in order 

 that they may be readily shaken down on to the cork without 

 producing permanent cloudiness. On the other hand, another 

 property which is in other cases desirable, namely, that of 

 giving bouquet, is of little moment here, where one wishes 

 to obtain products as neutral as possible." With the help 

 of his Johannisberg yeast, Wortmann was most successful 

 in solving these practical problems. 



Italian chemists and physiologists have also recently 

 turned their attention to the question of pure yeast culture. 

 Investigations in connection with this have been carried out 

 especially by Forti and Pichi. Several French, and some 

 Italian, investigators obtained no definite result in their ex- 

 periments ; there appear, however, now to be but few who 

 are entirely opposed to the new system. 



We shall next consider the conditions in the cider and 

 fruit-wine industry. In 1890, Kayser gave an account of 



