118 VINEGAR, CID1 



two determinations, which every vinegar manufacturer should be 

 able to make, are the only means of obtaining an accurate con- 

 trol of the working of the factory, and also serve, of course, for 

 settling the exact plan of operation from the start. 



If, with reference to the example given above, vinegar with 8 

 per cent, of acetic acid is to be prepared, the alcoholic liquid 

 must contain a total of 8.8 per cent, by weight of alcohol. Now 

 if the fabrication is commenced with an alcoholic liquid contain- 

 ing the total quantity of water, vinegar, and beer, but, for in- 

 stance, only 5 per cent, by weight of alcohol, the following 

 method will have to be pursued in order to accurately determine 

 when and how much alcohol has to be added. 



The first portion of the alcoholic liquid being poured into the 

 generator, the fluid running off is tested as to its content of acetic 

 acid and alcohol, the test being repeated after the second and each 

 successive pouring. Each test must show an increase in the con- 

 tent of acetic acid and a decrease in that of alcohol, and the latter 

 must finally have diminished so far that a new addition of alcohol 

 seems to be in order. If the test after the third pouring shows 

 the fluid to contain only 0.3 to 0.4 per cent, of alcohol, this 

 quantity would be quickly and completely oxidized in the fourth 

 pouring, and a certain quantity of acetic acid be at the same time 

 destroyed. Hence it is necessary to add, for instance, 2 per cent, 

 by weight of alcohol to the alcoholic liquid before the fourth 

 pouring. When this 2 + 0.3 or 2-f 0.4 per cent, of alcohol, which 

 the alcoholic liquid now contains, is again reduced after the sixth 

 or seventh pouring to 0.3 or 0.4 per cent,, the last addition of 

 1.8 per cent, of alcohol is made, the total quantity of alcohol, 

 5 + 24-1.8 = 8.8 per cent, having now been used. 



When, after a certain number of pourings, a test of the fluid 

 running off shows a content of 8 per cent, of acetic acid and only 

 0.1 or 0.2 per cent, of alcohol (a small remnant of alcohol should 

 always be present) the process is considered as finished, and a 

 further pouring into the generator would not only be useless labor, 

 but contrary to the end in view, since, after the complete oxida- 

 tion of the last remnants of alcohol, that of acetic acid would 

 immediately commence, and weaker vinegar would be obtained 

 after each pouring. 



