1835.] Great Britain and Ireland, 463 



distillers to employ a substitute, which is technically called 

 bub, and is prepared thus : a quantity of warm worts and 

 water is put into a vessel, with a quantity of meal or 

 flour, together with some yeast, the whole is well mixed 

 together and closely covered up ; a violent fermentation 

 almost immediately ensues, and in that state it is added to 

 the worts in the wash-backs, and excites the whole mass 

 to ferment; but should the fermentation, after some time, 

 be found to lag, some yeast is added, but for revenue 

 purposes, the whole quantity of bub and yeast added, is 

 restricted to the proportion of not more than five per cent, 

 on the quantity of worts previously collected ; in general, 

 however, that allowance is found more than sufficient. 

 Soon after yeast or bub has been added to the worts, fer- 

 mentation commences ; its first efi'ects are indicated round 

 the sides of the back, by the appearance of a scummy 

 looking matter on the surface of the worts, and the emis- 

 sion of small bubbles, which contain carbonic acid gas ; 

 the temperature increases as fermentation advances, its 

 progress is rather slow at first, but gradually increases, 

 and after some time proceeds with prodigious rapidity; 

 large bubbles of carbonic acid gas escaping set the whole 

 in motion, as if in a state of violent ebullition ; a large 

 quantity of froth collects on the surface of the liquor, 

 (which is now called wash) which often accumulates with 

 such rapidity, that several men are required to beat it down 

 with oars to prevent its spilling over the top ; indeed, on 

 some occasions, the beating on the top has been found in- 

 effectual, and the distiller forced to pump a portion of the 

 wash up to the coolers to lower its temperature, and then 

 return it, after which the process j^roceeded at a moderate 

 rate ; and, in all cases towards its close, the rate of fermen- 

 tation gradually diminishes and the temperature decreases, 

 till at last the wash acquires the temperature of the tun 

 room and remains quiescent. 



The object of the distiller is to carry fermentation to the 

 greatest possible extent, because his produce in spirits w411 

 be according thereto; and, indeed, the extent of the at- 

 tenuated gravity (that is, the difference of the specific gra- 

 vities before and after fermentation) is a pretty exact, per- 

 haps an absolute measure of the proportion of spirits con- 

 tained in the wash ; it is therefore adopted by the revenue 



