VINEGAR 197 



it must have access to the free oxygen of the air to convert 

 the alcohol into vinegar. If the alcoholic liquid is kept in 

 closed or completely filled containers, the process does not 

 occur. In the presence of too large quantities of alcohol, 

 above 14 per cent., the acetic bacteria can not grow, and 

 the alcohol is not attacked. 



The juice of most fruits contains sufficient sugar so that, 

 after the juice has undergone the alcoholic fermentation, 

 it can be used successfully for the preparation of vinegar. 

 The quality of the vinegar will depend on the source of the 

 juice. The vinegars made from wine and cider are most 

 highly prized for table use where the vinegar is used as a 

 condiment, since they contain many organic acids send 

 esters, derived from the fruits and formed in the fermen- 

 tation, not found in vinegars derived from other sources. 

 The flavor of these vinegars is therefore not simply that of 

 a solution of acetic acid. Most of the vinegar used in the 

 preparation of pickles commercially is distilled vinegar in 

 which the alcohol is obtained from the fermentation of 

 Imlrolyzed starch. This vinegar has no flavor other than 

 that of the acetic acid. In the pickling industry the pre- 

 servative action of the vinegar is the important thing, 

 rather than its flavor. 



On the farm the vinegar is most often prepared from 

 apple cider. It is necessary that an abundant supply of 

 air be furnished to the organism, and that the surface of 

 the liquid be large in proportion to its volume. These con- 

 ditions are secured when a barrel is used in which the alco- 

 holic liquid is to be changed to a solution of acetic acid. 

 The barrel should be filled from one half to two thirds full, 

 and then placed on its side. The circulation of air through 

 the barrel can be facilitated if openings are made in the 

 barrel-heads just above the level of the liquid. To prevent 



