VINEGAR FROM VARIOUS MATERIALS. 161 



it should be subjected to a special treatment the object of which 

 is to prepare a fluid containing no living yeast. 



By filtering the mash through a closely woven linen cloth the 

 particles of malt-husks, etc., are retained but not the cells of alco- 

 holic ferment which may be present and which, on account of 

 their minuteness, are difficult to separate from the fluid by filtra- 

 tion. It is, therefore, best to heat the mash before filtration to 

 about 140 F. whereby the ferment is killed and at the same time 

 a certain quantity of the albuminous substances dissolved in the 

 fluid rendered insoluble and separated. The heating of the mash 

 is best effected by passing it through a coil of tin-pipe placed in 

 a boiler filled with water kept constantly boiling. The tempera- 

 ture of the fluid can be readily regulated by increasing or decreas- 

 ing the velocity with which it passes through the coil. If the 

 fluid heated to 140 F. were allowed to cool in the air, a large 

 portion of the alcohol contained in it would be lost by evaporation, 

 and it is therefore allowed, after heating, to pass through a second 

 coil of pipe which is surrounded by cold water whereby it is 

 cooled to at least 86 F. This fluid is then filtered through a 

 linen bag, it being repeatedly poured back into the filter until it 

 runs off sufficiently clear. It will not, however, be obtained per- 

 fectly cldar in this manner, the yeast cells being too minute to be 

 retained by such a filter, but having been killed by heating, their 

 presence in the fluid is connected with no disadvantage. 



By mixing the filtered fluid with from 10 to 15 per cent, of its 

 volume of vinegar, an alcoholic liquid is obtained which can be 

 worked in the usual manner in the quick-process generators, and 

 yields an agreeable aromatic vinegar which clarifies rapidly and 

 improves by storing. 



According to the slow process, the fermented malt-wort is run 

 into casks placed in apartments called " stoves/ 7 since they are 

 heated by stoves or steam at a temperature ranging from 70 to 

 80 F. The casks are arranged in parallel rows, resting upon 

 long wooden beams elevated about 18 inches from the ground, 

 and having their bungs uppermost while a small hole on top of 

 the front head of each causes the circulation of air. 



A large saving of labor will be effected by connecting elevated 

 tanks holding the fermented wort with pipes and movable flexible 

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