go RESEARCHES ON YEASTS. 



under identical conditions in the Old Carlsberg Brewery, so 

 as to permit of a comparison being made ; and it was also 

 with beers obtained with the help of these two species that 

 Borgmann conducted the chemical investigations mentioned 

 above. 



No. i gives a rather thin head with low foam, a strong 

 attenuation, and it clarifies slowly and rather badly; the 

 sedimentary yeast is loose and rather slimy ; in the lager 

 cellar clarification also proceeds slowly. 



No. 2, on the other hand, gives a strong head, high foam, 

 feeble attenuation, quick and good clarification, a firm pasty 

 sediment and rapid clarification in the lager cellar. The beer 

 from both yeasts has a good and delicate taste, but the 

 No. 2 yeast gives a beer which is fuller, contains more carbonic 

 acid gas, and holds its head better ; the beer from No. I 

 yeast is, on the other hand, far more stable. When bottles of 

 this beer were kept in a dark cupboard at the ordinary room- 

 temperature and examined after three weeks, it was found 

 that no appreciable yeast sediment had formed ; but when 

 the beer from No. 2 yeast was similarly treated, the abundant 

 formation of yeast which occurred often rendered it undrink- 

 able even after ten days. 



The fermentations produced by the Carlsberg yeast No. I 

 have always caused surprise to brewers who have visited the 

 fermenting cellars of Old and New Carlsberg ; this yeast is, 

 in fact, one in which all the external characters looked for 

 by the practical brewer in a good brewery yeast are wanting, 

 and yet it gives a good and, in particular, an extremely stable 

 product. This latter property is of great importance, espe- 

 cially when, as is the case in Denmark, most of the beer is 

 sold in bottles. 



That the difference in the stability of the two beers 

 is not dependent solely upon the attenuation is shown by 

 the fact that the beer from No. 2 yeast, after attaining as 

 strong an attenuation by long storage as the beer from the 



