306 FERMENTATION OF BEER. 



beer the action of the oxygen of the air, and the 

 low temperature, cause complete transformation of 

 the sugar into alcohol ; the cause which would pre- 

 vent that result, namely, the extraction of the 

 oxygen of part of the sugar by the gluten, in its 

 conversion into ferment, being avoided by the in- 

 troduction of oxygen from without. 



The quantity of matters in the act of transfor- 

 mation is naturally greatest at the beginning of the 

 fermentation of must and wort ; and all the phe- 

 nomena which accompany the process, such as evo- 

 lution of gas, and heat, are best observed at that 

 time. These signs of the changes proceeding in 

 the fluid dimmish when the greater part of the 

 sugar has undergone decomposition ; but they must 

 cease entirely before the process can be regarded 

 as completed. 



The less rapid process of decomposition which 

 succeds the violent evolution of gas, continues in 

 wine and beer until the sugar has completely dis- 

 appeared ; and hence it is observed, that the spe- 

 cific gravity of the liquid diminishes during many 

 months. This slow fermentation, in most cases, 

 resembles the fermentation of Bavarian beer, the 

 transformation of the dissolved sugar being in part 

 the result of a slow and continued decomposition of 

 the precipitated yeast ; but a complete separation 

 of the azotised substances dissolved in it cannot 

 take place when air is excluded. 



The great influence which a rational manage- 



