Vinegar Methods 469 



the end of which time they require emptying and clean- 

 ing. 



In the " quick vinegar" method, the change of alcohol 

 into acetic acid is accomplished in vats filled with beech 

 shavings. Grain alcohol diluted with the vinegar is 

 allowed to trickle slowly through the shavings which, 



on account of the enormous surface exposed, present 

 extremely favorable conditions for the development of 

 the air-loving acetic ferments. We see, therefore, that 

 while in the Orleans method the bacteria multiply at 

 the surface of the liquid, in the " quick vinegar" method 

 they multiply throughout the body of the shavings. 

 When once thoroughly established on the surface of 

 the shavings, the ferments of the " quick vinegar" 

 method work with intense rapidity and accomplish 

 the transformation of large quantities of alcohol in a 

 comparatively short time. Under actual conditions in 

 the factory, various species may come to predominate, 

 among them yeasts and bacteria which oxidize the acetic 

 acid to water and carbon dioxids. 



The uncertainty as to the prevailing species is well 

 illustrated by some investigations of Henneberg. In 

 his studies of the acetic ferments in two vinegar factories 

 in Berlin, where the Orleans method was employed, 

 he found in casks standing close to one another Bac- 

 terium xylinum, Bacterium xylinoides, and Bacterium 

 vini acetati. In the other factory, the differences were 

 even more striking. Now, since the different species 

 differ not only in the amount of acetic acid produced by 

 them in a given time, but, also, in the quality, that is, 

 the aroma, taste, and appearance of the product, it is 



