1870.] Beer, Scientifically and Socially Considered. 309 



of whicli there are two or three descriptions, some of them occupy- 

 ing the floors of enormous chambers, which are moreover open to 

 the external atmosphere through the peculiar construction of the 

 windows. The principle of these refrigerators is, however, always 

 the same, the hot wort being allowed to flow over a series of tubes 

 through which cold water freely circulates. Sometimes the tubes 

 form a spiral coil, at others they run in parallel rows, covering the 

 entire floor of the chamber, but in every case they slope in an inclined 

 plane, so that when the wort is poured on at the higher end it flows 

 down slowly to the lower, becoming cooled in its passage. In 

 winter the cold air, which is admitted on all sides into the cooling 

 chamber, suffices to reduce the temperature of the wort in its passage 

 down the inclined plaue, but in summer it is necessary that the 

 water which flows through the pipes should be made as cold as 

 possible ; and at Messrs. Allsopp's, water is cooled on a large scale 

 for this purpose by the evaporation of ether. This is done out- 

 side of the main building, and the water thus cooled is con- 

 ducted all over the brewery, not only into the wort-refrigerators, 

 but wherever a low temperature is found requisite in the brewing 

 process. 



From the coolers the wort is next conveyed into the "fermenting 

 rounds," capacious vessels, each holding from 15 to 90 barrels, and an 

 idea may be formed of the magnitude of the operations carried on at 

 Allsopps', when it is mentioned that the new brewery (there are two) 

 has two fermenting rooms, each containing 136 such vessels, conse- 

 quently above 4000 barrels of beer may be fermented at one time. 

 Plate III. represents a portion of one of these fermenting chambers. 

 The principle involved in fermentation has already been described, as 

 the conversion of the saccharine matter in the wort into carbonic 

 acid and alcohol. As my readers are no doubt well aware, it is 

 effected by adding to the wort a quantity of fresh yeast from a pre- 

 vious brewing, and such an amount of carbonic acid gas is generated 

 that the invisible gas occupies the whole space between the surface 

 of the fermenting liquor and the rim of the vessel. A very curious 

 effect shown to visitors is to pass a hat through the apparently 

 empty space over the liquor in the fermenting vessel. This hat at 

 once fills with the invisible gas, which may then be poured into 

 another belonging to a visitor, just as we see chemical lecturers 

 illustrate the specific gravity of the carbonic acid gas they have been 

 making, by pouring it from one glass vessel to another. 



Let me, in passing, refer to the method in which, at Messrs. 

 Allsopp's, the superfluous yeast is utilized, for it is only at these 

 large establishments that every waste product is turned to good 

 account. First, as much of the ale as possible is allowed to 

 drain from the yeast, and then it is press-packed. The soft yeast 

 is placed between suitable cloths and transferred to hydraulic presses 



