EXPLANATION Or THE PLATES.
Figs. 1. and 2., Plate XL., explain the arrange ment of the Utensils and Machinery in a Porter Brewery on the largest scale; in which, however, it must be observed, that the elevation fig. 1. is, in a Feat degree, imaginary, as to the plane upon which it is taken ; but the different vessels are arranged so as to explain their uses most readily, and, at the same time, to preserve, as nearly as possible, the re lative positions which are usually assigned to each, in works of this nature.
The malt for the service of the brewery is stored in vast granaries or malt-lofts, usually situated is the upper part of the buildings. Of these, we have only been able to represent one at A, fig. 1.; the • others, which are supposed to be on each side of it, cannot be seen in tins view. Immediately beneath the granary A, is the mill, in the upper floor of whidi are two pair of rollers, for bruising or crush ing the grains of the malt. (An enlarged repre• sentation of the rollers is givea at figs. 3. and 4.) In the floor beneath the rollers are the miff-stases IA, where the malt is sometimes ground, instead of the simple bruising which it receives by passing be tween the rollers.
.The malt, when prepared, is conveyed by a trough into a chest d, from which it can be elevated by the action of a spiral screw e (see also. figs. 5. and 6.), into the large chest or binn B, for ground malt, situated immediately over the mashing-tun D. The malt is reserved in the bins tall wanted ; and it is that) let down into the mashing-tun, where the ex• tract is obtained by hot water supplied from the G.
copper water, for the service of the brewery, is ob tained from the well E, fry a lifting pump worked by the steam-engine, and the forcing-pipe f of this pump, teams the water up to the large reservoir water-back F, placed at the top of the engine house ; from this cistern iron pipes are laid to the copper G, and also every part of the establishment where cold water can be wanted for cleaning and washing the vessels. The copper G can be filled with cold water by only turning a cock 4; and the water, when boiled therein, is conveyed by the pipe g, into the mashing-tun D ; it is introduced beneath a false bottom, upon which the malt lies, and ris ing up through the holes in the false bottom, it ex tracts the saccharine matter from the malt; a greater or less time being allowed for the infusion, accord ing to circumstances. The instant the water is drawn off from the copper, fresh water must be let into it, in order to be boded ready for the second mashing; because the copper must not be left empty for a mo went, otherwise the intense beat of the Ire would melt the bottom. For the convenience of thus letting down, at once, as much liquor as will fill the bottom of the copper, a pan or second boiler is placed over the top of the copper, as seen in fig. 3. I'late %LI., and the steam rising from the copper, communicates a considerable degree of_ heat to the contents of the pan, without any expence of Rtel. This will be more
minutely explained hereafter.
During the process of mashing, the malt is agitat ed in the mash-tun to expose every part to the ac tion of the water. This is done by a machine con tained within the mash-tun, and put in motion by she horizontal shaft H, leading from the mill. The mashing-machine is shown to fig. 1. Plate XLI. *When the mashing is finished, the wort, or extract, is drained down from the malt,, into a vessel I, of simi lar dimensions to the mash-tun, and situated immedi ately beneath, from which it is called the under •back. Here the wort does not remain longer than is necessary to drain of the whole of it from the tun above. It is then pumped up by the three-barrelled pump k, into the pan at the top of the copper, by a pipe which cannot be seen in the Plate.
The wort remains in the copper pan until the water, for the succeeding mashes, is discharged from the copper. 'But this waiting is no loss of time, because the heat of the copper and the steam arising from it, makes the wort, which had become cooler, ready for boiling. The instant the copper is empty, the wort is let down from the pan into the copper, and the second wort is puniped up from the under back into the copper pan. The proper proportion of hops is thrown into the copper through the near hole, and then the door is shut down, and screwed fast, to keep in the steam, and cause it to rise up through pipes into the pan ; and by bubbling up, through the wort in the pan, it communicates so much heat, that it is soon ready for boiling in its turn ; for it is to be observed, that the different worts follow each other, through all the different vessels, with the greatest regularity, so that there is no loss of time, but every part of the apparatus is constantly employed. When the boiling of the wort has con tinued a sufficient time to coagulate the grosser part of the extract and to evaporate part of the water, the contents of the copper are run off through * large cock into the jack-back K ; which is a vessel of sufficient dimensions to contain it, and provided with a bottom of cast-iron plates, perfbrated with small holes, through which the wort drains and leaves the hops. The hot wort is drawn off from the jack back through the pipe h, by the three-barrelled pump, which throws it up to the coolers L ; this pump being made with different pipes and cocks of communication, to serve all the purposes of the brewery except that of raising the cold water from the well. The coolers L, are very shallow vessels, built over one another in several stages; and that part of the building in which they are contained, is built with open lattice-work on all sides, to admit the free current of When the wort is suffi ciently cooled to be put to the first fermentation, it is conducted in pipes, from all the different coolers, to the large fermenting vessel or gyle-tun M, which, with another similar vessel behind it, is of sufficient capacity to contain all the beer of one day's brew ings.