ACETIC FERMENTATION. 77 



about eight or ten litres of vinegar, which are replaced 

 by eight or ten litres of wine. 



A barrel in which this give-and-take of wine and 

 vinegar goes on is technically called a * mother.' The 

 starting of a 'mother' is not a rapid process. We 

 begin by introducing into the barrel 100 litres of very 

 good and very limpid vinegar ; then two litres only of 

 wine are added. Eight days after, three litres of wine 

 are added, a week later four or five, until the barrel 

 contains about 180 to 200 litres. Then for the first 

 time vinegar is drawn off in sufficient quantity to 

 bring back the volume of the liquid to about 100 

 litres. At this moment the labours of the ' mother ' 

 begin. Henceforward ten litres of vinegar may be drawn 

 off every eight days, to be replaced by ten litres of 

 wine. This is the maximum that a cask can yield in 

 a week. When the casks work badly, as is often the 

 case, it is necessary to diminish their production. 



This Orleans system has many drawbacks. It 

 requires three or four months to prepare what is 

 called a ' mother,' which must be nourished with wine 

 very regularly once a week under penalty of seeing it 

 lose all its power. Then it is necessary to continue 

 the manufacture at all times, whether the vinegar 

 be required or not. To reconstitute a ' mother,' one 

 must begin from the very beginning, a process which 

 involves a loss of three or four months' time. Lastly 

 a condition which is at times very inconvenient 



