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LVI. Observations on Fermentation. 

 By John N. Furze, Esq.* 



TN consequence of the practical inconveniences arising to 

 -*- brewers from want of control over the fermenting tuns, 

 and the changes in the worts dependent upon atmospheric 

 temperature, I was led to the following experimental obser- 

 vations. 



The infusion of malt being made according to the usual 

 practice of brewing, the wort, or infusion, is boiled with the 

 hops, and being subsequently cooled, yeast to the amount of 

 about one pound by weight to the barrel of wort is added, and 

 the whole transferred to the fermenting tun, The general form 

 of a brewer's fermenting tun being that of a simple open vessel, 

 the worts lie exposed during their change of state without 

 covering and with free access of air. This, as is evident, 

 must expose the fermenting mass to the variations of atmo- 

 spheric temperature, which, in their turn, either check or 

 hasten the operation to such an extent, that the ultimate suc- 

 cess of the brewing is endangered, and not unfrequently con- 

 siderable loss is sustained. These disadvantages are occa- 

 sionally avoided in some of the larger breweries by the use 

 of fermenting tuns, which are so far inclosed as to leave but 

 sufficient space for the escape of the gaseous matters arising 

 from the surface of the worts when the fermentation is in full 

 vigour. 



Having tried the above method without finding the desired 

 advantage to result from it, new measures of proceeding were 

 taken, as follows: — A circular tun was erected, whose total 

 content was 350 barrels, having a door in the side capable of 

 being made air-tight by lining its edges with coarse serge and 

 applying screw-pressure to the centre of it. To the upper 

 part of this tun, which was fitted with windows in the top and 

 sides to afford to the brewer an opportunity of viewing the 

 apparent changes in the worts, two India-rubber pipes were 

 attached, each of 1 inch internal diameter, to convey away 

 the gas generated during the process ; and, in order to pre- 

 vent external interference, the ends of the pipes were immersed 

 to the depth of about 3 inches in a vessel of water. 



These arrangements must not be confounded with the at- 

 tempts of some persons, both in this country and in France, 

 to condense vapours which were supposed to rise in great 

 abundance from fermenting liquids, and which are well known 

 to have disappointed the expectations of the projectors. On 

 two occasions, when the plan of condensation was tried by 



* Communicated by the Chemical Society ; having been read November 

 7, 1843. 



