216 AGEICULTUEAL AND INDUSTRIAL BACTERIOLOGY 



daily and a constant supply of vinegar thus secured. The 

 process has the advantage of providing abundant surface 

 area with consequent more rapid fermentation and it like- 

 wise preserves the acidifying membrane intact. 



It may be readily deduced that the larger the relative 

 area of the surface of the liquid exposed to the air, and the 

 more rapid and thorough the aeration, the more rapid, 

 under given conditions, will be the transformation of 

 alcohol into acetic acid. This has led to the manufacture 

 and development of various devices for hastening the manu- 

 facture of vinegar by exposing the liquid in very thin layers 

 to the action of organisms in the presence of air, layers 

 much thinner than those present in the Pasteur vat method. 

 The device probably most used at the present time is the 

 so-called quick or German method of vinegar manufacture. 

 The apparatus consists essentially of a tall cask or wooden 

 cylinder filled with beech-wood shavings. Beech-wood is 

 chosen in preference to other woods because it contributes 

 but little to the flavor of water coming in contact with it. 

 The shavings rest upon a false bottom bored full of holes. 

 An automatic sprinkling device is installed above the top 

 of the shavings. These shavings are first inoculated with 

 suitable bacteria, usually organisms of the type of Aceto- 

 bacter schutzenbachii. This may be accomplished by 

 sprinkling the beech-wood shavings with a good quality of 

 vinegar previously manufactured by the process or pure 

 cultures may be used. The alcoholic solution to be fer- 

 mented is sprayed or sprinkled over the top of the shavings 

 and trickles down over their surfaces to the bottom and 

 finally into a suitable receptacle. The surface area of the 

 shavings is relatively large. The liquid flows down over 

 them in very thin layers. The microorganisms find favor- 

 able conditions for growth inasmuch as air is constantly 

 passing in at the bottom, up through the shavings and out 

 at the top. A constant circulation of air is easily main- 



