208 "DISEASES" OF BEER, 



After the beer had stood in bottles for a few days at the ordinary room- 

 temperature, it was again examined ; the difference appeared to be still 

 less pronounced. It was, indeed, only when a comparison was made with 

 the infected beer that it was possible to detect that which had been 

 fermented partly with Sacch. Pastorianus I. and its variety. After 

 standing six days, the bottles containing the beer from E and F showed 

 a rather considerable sediment of yeast, and when shaken up it became 

 cloudy. The beer from A, on the other hand, was stable. Samples were 

 again collected after three months' storage ; the extract of A was 5*74 

 per cent. Balling, that of E and F 5 9 per cent. The beers from all three 

 were bright. With regard to taste and odour the same observations were 

 made as before. When the beer had been fourteen days in bottle in the 

 dark, and at the ordinary room-temperature, A contained no appreciable 

 sediment, and when shaken showed no sign of yeast turbidity. In the 

 beer from E and F, on the contrary, there was a distinct yeast sediment, 

 which on agitation rendered the beer slightly cloudy. 



The disagreeable taste and odour were noticeable also in 

 this case, although to a very slight extent. We have seen 

 above that, on the other hand, these symptoms of disease 

 manifest themselves in a marked degree when Sacch. Pas- 

 torianus I. is present in considerable quantity in the pitching 

 yeast. That this applies also to varieties of the above species, 

 I have convinced myself by direct experiment. 



In the experiments described, the disease yeast was added 

 to the wort at the commencement of the primary fermenta- 

 tion ; the following experiments, on the other hand, were 

 undertaken in order to ascertain the effect when infection 

 occurs at the end of the primary fermentation. 



III. Series of Experiments. At the conclusion of the primary fer- 

 mentation in the above first series of experiments, and after the beer had 

 been run from the fermenting vessels into the small lager casks, 20 cc. of 

 sedimentary yeast was taken from each of the vessels, C, D and E, and 

 introduced into about 17 liters of fermenting lager-beer wort, the primary 

 fermentation of which was just finished, and which was then removed to 

 the lager cellar. The small lager casks were treated in the manner 

 previously described, and were set aside in the lager cellar, together with 

 a control cask containing uninfected beer ; the temperature of the cellar 

 was 3-6 C. When it is recollected that the weight of yeast of the con- 

 sistency usually employed at least in the Copenhagen breweries amounts 

 to 4 grams to the liter of wort, it will be seen that the infection mentioned 

 was very considerable. As stated above, C contained exclusively Sacch. 

 Pastorianus /., D a mixture of this with Carlsberg bottom yeast No. i , 



