468 Bacteria in Relation to Country Life 



the alcohol into acetic acid, the bacteria proceed to oxi- 

 dize it further. On the other hand, when the vinegar is 

 quite strong, the bacteria and certain yeasts no longer 

 find conditions suitable for their growth, and the acid 

 is not burned up to water and carbon dioxid. 



Methods of using acetic ferments. — In the commercial 

 . preparation of vinegar, the acetic ferments may be util- 

 ized either according to the Orleans method, or to the 

 so-called "quick vinegar" (German, Schnellessig) method. 

 In the first of these, named after the locality in France 

 where it has long been employed, wine is allowed to turn 

 sour in barrels. The latter have a capacity of about 

 fifty-five gallons, and are provided with two holes near 

 the top, one for the introduction of the wine and the 

 removal of the vinegar, the other for the proper supply 

 of air. The casks used in the process are thoroughly 

 scalded with hot water, and then with hot vinegar. 

 When thus made ready for use, they receive about 

 twenty-two gallons of good, strong vinegar and about 

 one-half gallon of wine. 



At the end of eight days, a further quantity of wine 

 (somewhat more than one-half gallon) is added, and in 

 eight days more a somewhat larger amount; the addi- 

 tions being continued at similar intervals until the cask 

 contains forty to forty-four gallons. The vinegar is then 

 drawn off to leave about twenty-two gallons in the cask, 

 and about two and one-fifth gallons of fresh wine added. 

 After this, two and one-half gallons of vinegar are re- 

 moved every week and are replaced by the same quantity 

 of wine. When once properly started, the casks may be 

 suitable for a continuous use of six to eight years, at 



