Fig. 8, of Plate LXXVIII, is a section of Mr Bra mah's vent peg, to be put into the head of a cask when the liquor is drawn off, in order to admit the proper quantity of air, to allow the liquor to run off. AA is a section of the head of the cask, in which a taper screw B is placed for fastening the apparatus. The upper end of the screw is of large dimensions, and turned out into a cup of a cylindrical form, with a stud or pin ris ing up in the middle. A hole is drilled through the centre of the peg, to communicate with the interior of the cask at b. The cavity surrounding the stud being filled with water, the cap, or thimble C, must be invert ed, and dropped into the rabbet, which is turned in the top of the peg. Some small holes are drilled round in the cap at 1 and 2, to admit the air freely ; and as the lower edge of the cup is immersed in the water round the stud, nearly to the bottom of the cup, the ingress or egress of the air •i1 be prevented, except when the pressure of the air is augmented, by drawing the liquor out of the cask. This ingenious contrivance will be found very useful in drawing the liquor from the cask, to prevent it becoming flat or vapid from a greater ex posure to the air than is necessary Having thus given a brief description of the prin cipal utensils used in a brewery, we shall now proceed to sonic general observations on the different processes of brewing, without reference to the numerous varieties of beer, which are generally manufactured.
Account of the various fzroccsses employed in Brewing.
THE nature of the malt, as well as the quantity used, has a most immediate influence upon the liquor which is brewed from it. Malt is of three different kinds, pale, brown, and amber ; names derived from their dif _ _fercnt colours, which depend on the mode of drying the malt upon the kiln. Pale malt is dried with a slow fire, by degrees, and only just so far as effectually to prevent the future vegetation of the corn. Its colour does not materially distinguish it from barley. The malt kiln is a building of the figure of a large inverted pyramid, having a fire grate in its vertex. The base of the pyramid is covered by a floor, upon which the malt is spread to receive the action of the fire beneath, the smoke and heat of which pass through the floor: 'FIns, floor is constructed of iron bars, supporting tiles. which have large holes made nearly through them, from the lower side, and then very small holes pricked quite through, so as to form an earthen grating. In the mo dern kilns, wire floors have been used, similar to sieves ; and hair cloth sin cad upon them, has been employed for pale malt. These admit the heat to act on all the sides of every grain, and to dry it equally, without parch ing the outside. The fuel, for pale malt, is coke, made from Newcastle coals, which are thought to contain sufficient sulphur to render the malt of a light colour. Amber malt is, in all its properties, intermediate be tween pale and browmi malt, which is rendered so by being dried more rapidly, and with greater heat, so that the outside, and part of the flour, is in a measure char red. It is dried upon tiles, or close wire floors, or in
some places upon iron plates punched full of holes, or upon cast iron plates. Any kind of cokes are used for brown malt; and wood is sometimes employed towards the conclusion of the drying, to make a quick fire, and blow aft the mall. In this state the malt is considerably expanded, and will occupy a much greater space than before it came to the kiln.
The colour, and a great deal of the flavour of beer, depend on the malt from which it is brewed. Pale malt is used for fine ales, and pale beer ; amber malt is used for brown ale and beer, and to mix with pale for brew ing porter ; and brown malt is used fur porter ; but as the latter has lost part of its profitable quality of yield ing a strong and good wort, many of the London brew ers have adopted the plan of brewing porter from mix tures of pale and amber, or front pule malt only ; and in such cases they make up the flavour and colour of the liquor, by colouring malt made front burnt sugar, of which we shall speak in its proper place.
It is necessary, before the malt can be mashed with the greatest effect, to grind it, that, the outward husk being broken, the water may penetrate into the interior part of the grain. Every grain should be divided, but not reduced to a fine flour ; for in that state the action of the hot water tends to form a tenacious viscid paste, by melting the gluten of such parts of the flour as first come in contact with tt, and this envelopes the remain der of the malt, so as to prevent the water from pene trating to extract the fermentable matters ; and at the same time, the water which enters into the composition of the paste, will not leave the mash tun when the wort is let Mt, but a great proportion remains with it ; so that malt Low ground (that is fine), will not produce a %wort either so strong, or so much ill quantity, as when it is properly ground. The common method of grind ing malt is between millstones, in the same manner as flour, but the distance between the stones is made so great as not to cut the grain very fine, while at the same time they do not permit any of the smaller grains to escape without being cut. in order to prevent this, many of the London brewers have adopted the method of using a screen, as shown in Plate LXXVI I, to allow the ground malt to pass through, while it separates the uncut grains, which are broken by being introduced between a pair of iron rollers, similar to those used for flattening iron or other metals In other works, the rollers are employed instead of the millstones, and in this case it is impossible that any grains can escape unbroken. The external husks are thus rendered per vious to the water, and the violent pressure of the rol lers consolidates the flour contained in the corn, so as to prevent the water from saturating it quickly. This will take place in a greater degree in pale than in brown malt ; for the latter, from its high drying, becomes far inure brittle titan malt which is pale.