PRODUCED BY ALCOHOLIC FERMENTS. 203 



drawn off into bottles, and these were preserved in a dark cupboard at 

 the ordinary room-temperature. The beer was in all cases perfectly 

 bright when bottled, and it was also good as regards taste and odour. 

 After standing for fifteen days, the beer from A, B and C was still alike 

 and faultless in every respect. 



II. Series of Experiments. The method was the same as before, but 

 six vessels, A, B, C, D, E and F, were made use of. 



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



B 400 No. 2. 



C 350 No. i, 



and 50 grams of Sacch. exiguus. 



D 350 grams of Carlsberg bottom yeast No. 2, 



and 50 grams of Sacch. exiguus. 



E 400 grams of Carlsberg bottom yeast No. i. 



F 400 No. 2. 



The extract of the wort was 13 '9- per cent. Balling, and its temperature 

 at pitching was 7 C. The primary fermentation was finished after ten 

 days, and the extract was then 6 '80 per cent. Balling in A, 7*78 per cent, 

 in B, 7-13 per cent, in C, 7*70 per cent, in D, 6*72 per cent, in E, and 

 7*86 per cent, in F. The clarification was good in all cases, and was 

 best in B and F. As regards odour and taste all the beers were alike. 

 The beer from E and that from F were each infected with 75 grams of 

 Sacch. exiguus, as in the first experiments. 



After scarcely two months' storage the extract was 5 '74 per cent. 

 Balling in A, 6*72 per cent, in B, 5*90 per cent, in C, 6*56 in D, 

 5 '74 per cent, in E, and 6*64 per cent, in F. The beer, which was now 

 perfectly bright, was drawn off into bottles as described above, and after 

 these had stood eleven days they showed only a very slight sediment. 

 No difference could be detected in this respect between the beer which 

 had been infected with Sacch. exiguus and the uninfected beer. All the 

 samples had a good taste and odour ; after fourteen days there were still 

 no signs of disease. After three months' storage the extract was 5*74 

 per cent. Balling in A, 6*39 per cent, in B, 5*82 per cent, in C, 6*39 per 

 cent, in D, 5 '74 per cent, in E, and 6*31 per cent, in F. The beer had in 

 each case preserved its brightness perfectly, and also its good taste and 

 odour. After being fourteen days in bottle under the conditions men- 

 tioned, there was no sign of yeast turbidity or of any disease whatever. 



In the experiments described, Sacch. exiguus was in some 

 cases added to the wort with the normal pitching yeast at 

 the commencement of the primary fermentation, and in others 

 was introduced after the termination of the primary fermenta- 

 tion, at the commencement of the storage period. In addition 

 to these experiments I made others in which the beer was 



