126 VINEGAR, CIDER, AND FRUIT- WINES. 



entirely avoided and the slighter ones due to insufficient acetous 

 fermentation of the ferment readily removed. 



As regards the nourishing substances of the ferment, irregu- 

 larities can actually occur only in working continuously with an 

 alcoholic liquid composed exclusively of water and alcohol. In 

 such alcoholic liquid the nitrogenous substances necessary for the 

 nourishment of the ferment are wanting, nor are the phosphates 

 present in sufficient quantity. The consequences are the same as 

 observed in every insufficiently nourished fermenting organism : 

 the fermenting activity suddenly diminishes, augmentation pro- 

 ceeds sluggishly and ceases entirely if abundant nourishment is 

 not introduced. Hence it may happen that from a generator 

 containing alcoholic liquid composed only of water, alcohol, and 

 vinegar, the greater portion of the alcohol suddenly runs off' un- 

 changed, the temperature in the interior of the generator at the 

 same time falling and the draught of air ceasing soon afterwards. 

 When these phenomena appear it should first be ascertained 

 whether the disturbance is not due to too slight a current of air. 

 For this purpose the draught-holes are entirely opened, and if 

 the temperature rises the generator gradually resumes its normal 

 working. If, however, no improvement is observed, the disturb- 

 ance is due to defective nourishment, and the composition of the 

 alcoholic liquid has to be changed, which is best effected by the 

 addition of a few per cent, of beer or of fermented alcoholic 

 mash, both containing a sufficient quantity of phosphates and 

 albuminous substances. The use of sweet beer wort or of malt 

 extract has also been highly recommended for "strengthening 

 weak-working generators." These substances also furnish albu- 

 minous bodies and phosphates to the alcoholic liquid ; they also 

 contain, however, maltose and dextrin, and as it has not yet been 

 ascertained whether the latter and the carbohydrates in general 

 can be consumed and digested by the ferment, they possibly may 

 pass unchanged into the vinegar. Honey and glucose are also 

 sometimes used for strengthening purposes, but while the former 

 might be useful on account of the abundance of salts and nitro- 

 genous substances it contains, no substances of any value to the 

 ferment are present in the latter. At any rate the addition of 

 beer, mash, or malt extract is to be preferred. 



