THE BAVARI VN PROCESS. 31S 



experimental knowledge has here led to the solution of one of the 

 most beautiful problems of the theory of fermentation. 



Wort is proportionally richer in gluten than in sugar, so that, 

 during its fermentation in the common way, a great quantity of 

 yeast is formed as a thick scum. The carbonic acid evolved 

 during the process attaches itself to the particles of the yeast, 

 by which they become specifically lighter than the liquid 

 in which they are formed, and rise to its surface. Gluten, in the 

 act of oxidation, comes in contact with the particles of the decom- 

 posing sugar in the interior of the liquid. The carbonic acid 

 from the sugar and insoluble ferment from the gluten are dis- 

 engaged simultaneously, and cohere together. 



A great quantity of gluten remains dissolved in the fermented 

 liquid, even after the transformation of the sugar is completed, 

 and this gluten causes the conversion of the alcohol into acetic 

 acid, on account of its strong disposition to attract oxygen, and to 

 undergo decay. Now, it is plain, that with its separation, and 

 that of all substances capable of attracting oxygen, the beer 

 would lose the property of becoming acid. This end is com- 

 pletely attained in the process of fermentation adopted in 

 Bavaria. 



The wort, after having been treated with hops in the usual 

 manner, is thrown into very wide flat vessels, in which a large 

 surface of the liquid is exposed to the air. The fermentation is 

 then allowed to proceed, while the temperature of the chambers 

 in which the vessels are placed is never allowed to rise above 

 from 45° to 50° F. The fermentation lasts from three to six 

 weeks, and the carbonic acid evolved during its continuance is 

 not in large bubbles which burst upon the surface of the liquid, 

 but in small bubbles like those which escape from an acidulous 

 mineral water, or from a liquid saturated by high pressure. The 

 surface of the wort is scarcely covered with a scum, and all the 

 yeast is deposited on the bottom of the vessel, in the form of a 

 fine viscous slime. 



In order to obtain a clear conception of the great difference 

 Detween the two kinds of fermentation, it may perhaps be 

 sufficient to recall to mind the fact, that the transformation of 

 gluten or of other azotized matters is a process consisting of 



