PRODUCED BY ALCOHOLIC FERMENTS. 207 



again, and, like that from E, it remained twenty-one days in bottle in 

 the room without exhibiting signs of yeast turbidity. After Jive months' 

 storage the beer from D still possessed the disagreeable bitter taste in a 

 high degree. The beer from C was at this time still cloudy, and it was 

 only after six months' storage in the lager cellar that it became bright ; 

 the taste was still as nauseous as before. 



The result is, in the main, the same when a mixture of 

 Sacch. Pastorianus I. with another brewery yeast in the place 

 of the Carlsberg bottom yeast No. I is employed. 



Thus the disease mentioned is very pronounced when one- 

 fifth of the pitching yeast consists of Sacch. Pastorianus I. 

 In one experiment made with the large Pasteur vessels con- 

 taining ij hectoliters of aerated wort of the same character as 

 that previously mentioned, it was found, however, that the 

 disease was also produced when the same disease yeast was 

 present to the extent of only -j^ of the pitching yeast. This 

 experiment, however, was not made exactly under brewery 

 conditions, and I will, therefore, pass on to the description of 

 the following experiments. 



II. Series of Experiments. These were conducted in the same 

 manner as the first experiments, and in the same fermenting cellar. The 

 wort had an extract of 13*9 per cent. Balling ; its temperature at pitching 

 was 7 C. 



A was pitched with 400 grams of Carlsberg bottom yeast No. I. 



E 380 No. i, 



and 1 8 grams of Sacch. Pastorianus I. 



F 380 grams of Carlsberg bottom yeast No. i, 



and 1 8 grams of a variety of Sacch. Pas- 

 torianus I. 



In E and F the disease yeast thus formed % part of the total pitching 

 yeast. After ten days the extract was 6*80 per cent. Balling in A, 7*37 

 per cent, in E, and 7*86 per cent, in F. The beer clarified well in A, 

 and only fairly well in E and F. As regards taste and odour, there was 

 no marked difference in the beers from the three vessels. 



When the beer had been in the lager cellar for about two months, A 

 was found to have an extract of 5 '74 per cent. Balling, E 6' 15 per cent, 

 and F 6 ' 23 per cent. ; the beer was bright in all three cases. A had the 

 usual good taste and odour, E and F, on the other hand, possessed an 

 objectionable odour and a bitter disagreeable taste, but only in a very 

 slight degree. This test was made directly after the beer had been 

 drawn off, and, as usual, by several persons : in fact, by beer experts. 



