100 VINEGAR, CIDER, AND FRUIT- WINES. 



no other than the desired ferment is developed, is not difficult, it 

 being only necessary to prepare a fluid especially adapted for its 

 nourishment and allow it to stand at a suitable temperature in order 

 to obtain in a few days a vigorous growth produced by a few 

 individual germs reaching the fluid from the air. The best fluid 

 for the purpose is one which contains, besides a large quantity of 

 water, about 85 to 90 per cent., a certain amount of alcohol and 

 acetic acid and very small quantities of nitrogenous substances 

 and mineral salts. Hence its preparation is not difficult, it being 

 only necessary to mix ordinary vinegar and alcohol in suitable 

 proportions and add a small quantity of a fluid containing nitro- 

 genous substances and mineral salts, such as wine, cider, beer or 

 malt extract. Numerous experiments have shown that a fluid 

 containing from 4 to 6 per cent, of acetic acid and the same 

 quantity of alcohol with the addition of a small quantity of one 

 of the above-mentioned fluids is best adapted for the vigorous 

 nourishment of the vinegar ferment. Ordinary table vinegar 

 contains as a rule from 4 to 6 per cent, of acetic acid ; the ave- 

 rage percentage of alcohol is in wine from 8 to 10 ; in cider from 

 4 to 6 ; and in beer from 3 to 5. Taking this statement as a 

 guide, the preparation of a fluid containing from 4 to 6 per cent, 

 of acetic acid, 4 to 6 per cent, of alcohol, and the required nitro- 

 genous combinations and salts will not be difficult. 



Fluids of this composition are obtained by mixing, for in- 

 stance, equal parts of cider and vinegar, or one part of wine 

 with two of vinegar, or one part of beer with three of vinegar, 

 and adding 5 per cent, of 90 per cent, alcohol to the mixture. 

 Such mixtures possessing the power of vigorously nourishing the 

 vinegar ferment can at the same time be considered as types for 

 the preparation of alcoholic liquid of suitable composition. 



To assure the exclusive development of vinegar ferment upon 

 any of the above-mentioned mixtures it is best to heat it to the 

 boiling point of water. Young wine as well as cider contains 

 considerable quantities of albuminous substances in solution, and 

 fluids of this nature being well adapted for the nourishment of 

 the mold ferment, the development of the latter 'might increase 

 to such an extent as entirely to suppress the vinegar ferment and 

 thus render its cultivation a failure. Beer is also very suitable 



