VINEGAR FROM VARIOUS MATERIALS. 165 



would be obtained which contains a considerable quantity of 

 unfermented sugar. The following table shows the average 

 content of sugar and free acid in the most common varieties 

 of fruits : 



According to the above table, currants, gooseberries, raspber- 

 ries, etc., contain on an average scarcely 6 per cent, of sugar, and 

 consequently their juice, after complete fermentation, would give 

 a fluid with about 3 per cent, of alcohol, from which vinegar 

 with about 2J per cent, of acetic acid could be obtained. Such 

 vinegar being, however, too weak, those berries would not seem 

 suitable for the direct preparation of vinegar. Moreover, the 

 complete fermentation of the juice of most berries is very diffi- 

 cult, the free acids, among which malic acid preponderates, ex- 

 erting an injurious influence upon the progress of fermentation. 



Vinous .fluids of an agreeable taste can, however, be prepared 

 from berries, and from them an aromatic and finely flavored 

 vinegar, by decreasing the content of acid in the juice and in- 

 creasing that of sugar. The juice of currants, as seen from the 

 above table, contains in round numbers 6 per cent, of sugar and 

 2 per cent, of malic acid. By diluting this juice with an equal 

 volume of water a fluid containing 3 per cent, of sugar and 1 per 

 cent, of acid is obtained, and the content of the former can be in- 

 creased at will by the direct addition of sugar. 



By compounding, for instance, 100 quarts of currant juice with 

 100 quarts of water and adding 34 Ibs. of sugar, the resulting 

 fluid contains about 20 per cent, of sugar and after complete fer- 

 mentation gives a fluid with about 9.5 per cent, of alcohol, which 

 yields vinegar of nearly 9 per cent, strength. The taste of this 



