250 PRESENT POSITION OF 



in a brewery, may in a shorter or longer period become a 

 more or less pure culture of a single species, owing to the 

 other species originally present becoming suppressed. If 

 such a yeast proves satisfactory, it is not because it was 

 at the commencement a composite yeast, but because the 

 conditions of cultivation brought about the suppression of 

 the useless varieties. The main result arrived at is that 

 also in the case of English high fermentation, it will prove 

 most rational to adopt my system of pure culture in its 

 simplest form. 



The following is a statement made by Dr. Sykes during 

 the discussion which followed the reading of Jorgensen's 

 paper : " Not long ago I visited a brewery some distance 

 from town, where I found a Hansen yeast-cultivation appara- 

 tus in full working order, and a large quantity of beer being 

 produced with the single cell yeast which had been grown 

 in it. On tasting the beers so produced, I found the flavour 

 satisfactory, and the after fermentation all that could be 

 desired. One thing that particularly struck me was the 

 excellent conditioning in a cask of lightly-hopped beer, 

 which had been removed from the growing chamber of the 

 yeast apparatus. This beer had been fermented under con- 

 ditions which rigorously excluded all contamination from 

 without, and it had been afterwards placed in a perfectly 

 clean cask. These observations, coupled with the results 

 obtained at Messrs. Combe's brewery, irresistibly led me 

 to the conclusion that beer could be successfully produced 

 with single cell yeast." 



In conclusion, I will only give the two following state- 

 ments by Professor Petit, director of the Ecole de brasserie 

 de Nancy, and Professor C. J. Lintner, of the Polytechnic at 

 Munich. Petit expresses himself as follows : " I am rather 

 distrustful of mixed yeasts. Moreover, such a yeast keeps 

 by no means constant, the relative proportions of the dif- 

 ferent races changing rapidly, and in different directions, 



