146 



VINEGAR, CIDER, AND FRUIT-WINES. 



upwards. In front of the bung-hole this tube is provided with 

 an expansion in which is fitted by means of a cork a tube, b, bent 

 at a right angle. While the vinegar is stored, this tube stands 

 upright as indicated by the dotted lines, and is secured to a rubber 



Pis. 38. 



hose reaching to the bung-hole. By turning the tube downward 

 the fluid runs out through the tube a until its level has sunk to 

 the dotted line. 



Sometimes the vinegar is not rendered entirely clear by storing^ 

 and filtering has to be resorted to. Before referring to this ope- 

 ration a few words will be said in regard to the storing of vinegar. 



The vinegar brought into the storage barrels contains the fol- 

 lowing constituents : Water, acetic acid, alcohol (very little), alde- 

 hyde (very little), acetic ether, vinegar ferment (living and dead), 

 extractive substances (depending on the nature of the alcoholic 

 liquid used). Moreover, there arc frequently found alcoholic fer- 

 ment (from the beer) and vinegar eels and vinegar mites, if these 

 animals exist in the factory. 



By filling the storage barrels to the bung-holes and closing 

 them air-tight, the vinegar eels and vinegar mites die in a short 

 time for want of air and fall to the bottom. The living vinegar 

 ferment present in the fluid must assume the form in which it can 

 for some time exist without free oxygen, i. e., of mother of vine- 

 gar. When in consequence of the shrinkage in the volume of the 

 vinegar by cooling the air penetrates through the pores of the 

 wood, it is first utilized for the conversion of the small quantity 

 of aldehyde into acetic acid, and later on enables the vinegar fer- 



