222 "DISEASES" OF BEER, 



sented to the carrying out of these experiments on a large 

 scale in the brewery. In some cases the beers produced 

 with the help of the two yeasts were mixed after the com- 

 pletion of the primary fermentation, so that the lager casks 

 contained both kinds of beer ; in other cases we employed 

 a composite pitching yeast consisting of the two species. 

 As it had been previously found that in spite of its deficiences 

 the No. I yeast was best suited to the Old Carlsberg brewery, 

 this yeast was the chief constituent of the composite yeast 

 in all cases ; and where the two beers were mixed, that fer- 

 mented with this yeast also formed the main bulk of the 

 mixture. 



I have omitted to make notes of the details of these 

 experiments ; the main result was a negative one this mixed 

 beer, as it may be called, did not attain the desired fulness, 

 and was in all cases much less stable than the beer produced 

 exclusively with Carlsberg bottom yeast No. i. The term 

 stability has reference here, as in the foregoing chapters, to 

 the behaviour of the finished stored beer with regard to the 

 formation of yeast sediment, and does not refer to bacterial 

 diseases. The experiments were, indeed, always carried out 

 with pure cultures of well-known yeasts. By stable lager 

 beer, I mean lager beer which can be kept in well-corked 

 bottles for two to three weeks at the ordinary room-tempera- 

 ture, without forming any appreciable yeast sediment, and 

 which will not become cloudy when well shaken after the 

 lapse of the period mentioned. 



As these experiments with mixtures led to no satisfactory 

 result, they were discontinued, and the No. I yeast was 

 employed in by far the greater part of the brewery ; some 

 years ago, the employment of the No. 2 yeast was com- 

 pletely given up, and the fermentations at Old Carlsberg 

 are now exclusively conducted by means of the first-named 

 species. 



I did not however, by any means, regard the question 



