126 PUBLIC HEALTH CHEMISTRY 



heaps, called " couches," and allowed so to remain for 

 20 to 48 hours, to enable it to develop sufficient heat to 

 ensure equable and good germination. Thereafter it is 

 spread out on floors, where rapid germination proceeds, 

 the plumule growing up the back of the grain and the tiny 

 rootlets being put forth. In 10 to 14 days the plumule is 

 halfway to three-quarters up the back of the grain. Further 

 growth is then stopped by running the malt on to the 

 floors of the " kilns," where it is gradually heated until 

 dry, when the heat is increased. If pale malt is desired, 

 the temperature is not raised above 185 F., but for black 

 or brown malts for black beers, the malt is caramelized. 

 The heated malt is then sifted or screened, to get rid of the 

 sproutlings ; the sif tings are ground into " grist," and the 

 grist is run into the " mash-tun," a large covered vessel, 

 containing a proper proportion of the brewing-water, at a 

 temperature of 140 to 152 F. for pale ales, and 144 to 

 150 F. for black beers. In the mash-tun it is well mixed for 

 15 to 30 minutes, allowed to stand for two hours more, and 

 then the liquor, or " wort," run off into a receiving vessel. 

 More water is run into the mash-tun, and the solids are 

 washed or " sparged," the water not being used hotter than 

 160 F. to prevent the solution of starch. After four hours' 

 sparging the liquor is run off, the speed being increased 

 as the solids settle, and is mixed with the first wort. The 

 mixture is then boiled in the " copper," the larger portion 

 of the hops added, and after one to two hours' boiling, run 

 out and the hops allowed to settle. The bright, clear, 

 supernatant liquid is then run into large flat trays or 

 coolers, and over coils of pipes in which cold water is 

 circulating- (refrigerators), its temperature being reduced 

 to a suitable one for fermentation (6o F. or under). At 

 this stage the specific gravity of the wort is taken by the 

 Excise officers with a Bates' saccharometer, which is a 

 modified hydrometer. The Customs' standard is a sp. gr. 

 of 1055 at 60 F. After allowing 6 per cent off for wastage, 

 they charge 7s. o,d. per 36 gallons, as duty. The wort is 

 now run into tuns made of wood, slate, or stone, about 

 1 lb. of yeast per barrel being mixed with it as it is run in. 

 Fermentation now takes place, and is continued until the 

 beer reaches the specific gravity desired by the brewer. 



