198 "DISEASES" OF BEER, 



several fermentations in the brewery. The No. 2 yeast, how- 

 ever, re-acquired its normal properties more quickly than 

 No. I ; both underwent temporary modification, the one to 

 a greater degree than the other. 



The beer produced by the fermentation of the non-aerated 

 wort was highly opalescent ; and this opalescence was, as a 

 rule, only slightly diminished by protracted storage ; the beer 

 also remained cloudy after it had been exposed for several 

 days to the ordinary room-temperature. This applies especi- 

 ally to the beer produced from Carlsberg bottom yeast No. i. 

 The aerated wort gave bright beer, the non-aerated gave 

 cloudy, opalescent beer. 



On the other hand, the result was quite different when 

 the non-aerated wort was pitched with a yeast consisting not 

 only of one of the bottom yeasts mentioned, but which con- 

 tained also a small quantity of the disease yeast Sacch. 

 Pastoriamis III. In this case, the beer produced from the 

 non-aerated wort was also bright ; the disease yeast thus 

 played the part as it were of a curative. 



On repeating these experiments some years later, a dif- 

 ferent result was obtained. As a rule, it was found that 

 the beer obtained from non-aerated wort was also bright ; 

 yet these new experiments, like the previous ones, were 

 made with ordinary lager-beer wort from the Old Carlsberg 

 brewery, and with the same species of yeasts. Some of the 

 experiments were made in the laboratory with vessels of 

 ten liters capacity and containing seven liters of wort, others 

 in a fermenting cellar under the conditions obtaining in the 

 brewery. In all cases the beers were stored at a temperature 

 of 1-2 C., and, in fact, care was taken to imitate as far as 

 possible the conditions obtaining in practice. It was only in 

 one of these new experiments that the beer from non-aerated 

 wort was opalescent. This experiment was conducted in 

 four of the fermenting vessels in the fermenting cellar of 

 Old Carlsberg, and which have been previously mentioned ; 



