224 MICRO-ORGANISMS AND FERMENTATION. 



any one who saw the foam and ' head ' on the beers could not 

 doubt. 



" Mr. de Bavay tells me that he frequently obtains a well- 

 marked secondary cask-fermentation in a fortnight from 

 racking the beer, and this in cases where the yeast used 

 was fresh from the laboratory, and therefore practically free 

 from the slightest intermixture of other types of yeast." 

 (De Bavay^s brewery in Melbourne is worked on the top- 

 fermentation system.) 



MacCartie, therefore, basing his opinion on these facts, 

 has no doubt but that within a few years Hansen's system 

 will also be adopted in all the important top-fermentation 

 breweries of the world. His detailed account is of great 

 interest, since it again affords proof, obtained in actual 

 practice, that there are differences in the species of Saccharo- 

 myces cerevisice, and thus it also proves the necessity for 

 making a selection from these species with reference to 

 practical requirements. 



W. R. Wilson writes l : 



" Some gyles have been prepared with pure yeast, and 

 have been compared against ale brewed at the same time, but 

 pitched with ordinary yeast. It is admitted on all hands 

 that, so far as can be at present ascertained, the pure-yeast 

 ale is immeasurably superior to the other. Hansen's pure 

 yeast system applied to English high fermentations, appears 

 to be equally suitable for ales, porters, and stouts." 



With regard to the employment of the system in top- 

 fermentation breweries in North France and Belgium, the 

 following statements may be quoted. 



Dr. E. Kokosinski, director of the laboratory at Lille, 

 writes 2 : 



" In August, 1888, after three years' preparatory study, 



1 The Brewers' Journal, 1892, p. 527. 



2 Application industrielle de la me"thode Hansen a la fermentation 

 haute dans le Nord de la France. Compt. rend, de la Station scientifique 

 de Brasserie, Gand, 1890. 



