FABRICATION OF WIXE-YIXEGAR. 195 



where it quickly augments and converts the remainder of the 

 alcohol in the fluid into acetic acid. The only difficulty to be 

 overcome in preparing the vinegar according to this method is 

 the appearance of the mold ferment upon the surface of the fluid. 

 This can, however, be met by removing the growth of this fer- 

 ment, which is recognized by its pure white color, by means of 

 a spoon as soon as it has attained the thickness of a few milli- 

 meters. The vinegar ferment then soon commences to augment 

 and suppresses the further growth of the mold ferment. 



If the grapes originally used contained from 18 to 20 per cent, 

 of sugar, the vinegar from the lees prepared according to this 

 method shows, if not too much water has been used, a content of 

 at least 4 or 5 per cent, of acetic acid, and consequently is imme- 

 diately fit for table use. By long storing in barrels kept filled 

 up to the bung-holes, it acquires a flavor resembling that of vine- 

 gar prepared from wine. 



On account of the simplicity and the slight expense connected 

 with it the above-described process is especially adapted for the 

 preparation of vinegar for household purposes. But for commer- 

 cial purposes on a large scale it is advisable to obtain a stronger 

 and consequently more valuable product by a somewhat modified 

 process. 



For the preparation of stronger vinegar from a fluid it is neces- 

 sary to give it a higher content of alcohol or sugar. As is \vell 

 known, 1 per cent, of sugar in a fluid yields after fermentation in 

 round numbers 0.5 per cent, of alcohol, and the latter about 0.4 

 per cent, of acetic acid. These figures, though not absolutely 

 correct, are sufficiently so for practical purposes. Hence, if the 

 content of acetic acid is to be increased 1 per cent., 1.2 per cent, 

 of alcohol or 2.4 per cent, of sugar has to be added to every hec- 

 toliter (22 imp. gallons) of the fluid to be worked into vinegar. 



The substances which impart to wine-vinegar its greater value 

 as compared with ordinary vinegar are derived from the grape ; 

 they are found in abundance in the must as well as in the fresh 

 lees, and are yielded by the latter to water. Hence, excellent 

 wine-vinegar can be prepared from the lees by working accord- 

 ing to the following method : 



The lees are brought directly from the press into a vat and 



