THE MANUFACTURE OF VINEGAR. 455 



days in cold water. The wine remaining in contact with these chips 

 for three or four days deposits most of its sediment. 



The cask is first one-third filled with good vinegar and ten or fifteen 

 liters of the filtered wine added. The same amount of wine is added 

 every week for four weeks by which time the cask is half full. At the 

 end of the fifth week an amount of vinegar equal to the wine added is 

 drawn off and the operation repeated. The vinegar is filtered as soon as 

 it is drawn off, placed in full tightly bunged casks and kept in a cool cellar. 



PASTEUR METHOD. Pasteur long ago pointed out the defects of the 

 old Orleans method and suggested improvements. The main defects 

 of the old method are that it is^ cumbersome, laborious, slow and costly. 

 There is a loss of about 10 per cent of material by evaporation and the 

 repeated additions of liquid break the bacterial film, which then sinks to 

 the bottom, grows anaerobically and exhausts the nutrients of the solution 

 without producing acetic acid. These submerged bacteria finally form 

 a large gelatinous mass which interferes with the regular progress of the 

 operations, depreciates the quality and necessitates frequent expensive 

 cleanings of the casks. Many attempts, more or less successful, to 

 overcome these defects in accordance with Pasteur's ideas have been 

 made, that of Claudon is one of the best and will serve to exemplify all. 



It consists essentially of a wide, shallow, covered square vat, furnished 

 with numerous openings near the top by which the entrance of air can be 

 facilitated and regulated. This vat is filled to the bottom of the air vents 

 with a mixture of four parts of good new vinegar and six parts of wine 

 which has been pasteurized at 55 and, when necessary, filtered. On 

 top of this liquid is floated a light wooden grating which helps to support 

 the bacterial film and prevent its breaking and submerging during the 

 various operations. When filled, the process is started by placing a 

 small quantity of a good bacterial film on top of the liquid which soon 

 becomes completely covered when the proper conditions of temperature 

 and aeration are maintained. 



Each acetifying vat is connected with a small measuring vat from 

 which the proper amount of liquid is added every day after a correspond- 

 ing amount of vinegar has been removed. These two vats constitute a 

 unit, several of which, usually six, are united in a battery. A factory 

 includes several of these batteries. 



The batteries are 'fed from a large vat or reservoir, where the mixture 

 of wine and vinegar is prepared and stored. The vinegar drawn from 



