Plan, Machinery

ery, and Utensils of a great Brewery. — Figs. 103. and 104. represent the arrangement of the utensils and machinery in a porter brewery on the largest scale; in which, however, it must be observed that the elevation fig. 103. is in a great degree imaginary as to the plane upon which it is taken; but the different ve els are arranged so as to explain their uses most readily, and at the same time to preserve, as nearly as po ible, the relative positions which are usually a igned to each in works of this nature. The malt for the supply of the brewery is stored in vast granaries or malt-lofts, usually situated in the upper part of the buildings. Of these, I have been able to represent only one, at A , fig. 103. : the others, which are supposed to be on each side of it, cannot be seen in this view. Immediately beneath the granary A , on the ground floor, is the mill; in the upper story above it, are two pairs of rollers, fig. 101 , 102 , and 103 , under a , a , for bruising or crushing the grains of the malt. In the floor beneath the rollers are the mill-stones b , b , where the malt is sometimes ground, instead of being merely bruised by pa ing between the rollers, under a , a . The malt, when prepared, is conveyed by a trough into a chest d , to the right of b , from which it can be elevated by the action of a spiral screw, fig. 105. , enclosed in the sloping tube e , into the large chest or binn B , for holding ground malt, situated immediately over the mash-tun D . The malt is reserved in this binn till wanted, and it is then let down into the mashing-tun, where the extract is obtained by hot water supplied from the copper G , seen to the right of B . The water for the service of the brewery is obtained from the well E , seen beneath the mill to the left, by a lifting pump worked by the steam engine; and the forcing-pipe f of this pump conveys the water up to the large reservoir or water-back F , placed at the top of the engine-house. From this cistern, iron pipes are laid to the copper G (on the right-hand side of the figure), as also to every part of the establishment where cold water can be wanted for cleaning and washing the ve els. The copper G can be filled with cold water by merely turning a cock; and the water, when boiled therein, is conveyed by the pipe g into the bottom of the mash-tun D . It is introduced beneath a false bottom, upon which the malt lies, and, rising up through the holes in the false bottom, it extracts the saccharine matter from the malt; a greater or le time being allowed for the infusion, according to circumstances. The instant the water is drawn off from the copper, fresh water must be let into it, in order to be ready for boiling the second mashing; because the copper must not be left empty for a moment, otherwise the intense heat of the fire would destroy its bottom. For the convenience of thus letting down at once as much liquor as will fill the lower part of the copper, a pan or second boiler is placed over the top of the copper, as seen in fig. 103. ; and the steam rising from the copper communicates a considerable degree of heat to the contents of the pan, without any expense of fuel. This will be more minutely explained hereafter. ( See fig. 107. ) During the proce of mashing, the malt is agitated in the mash-tun, so as to expose every part to the action of the water. This is done by a mechanism contained within the mash-tun, which is put in motion by a horizontal shaft above it, H , leading from the mill. The mash machine is shown separately in fig. 106. When the operation of mashing is finished, the wort or extract is drained down from the malt into the ve el I , called the under-back , immediately below the mash-tun, of like dimensions, and situated always on a lower level, for which reason it has received this name. Here the wort does not remain longer than is nece ary to drain off the whole of it from the tun above. It is then pumped up by the three-barrelled pump k , into the pan upon the top of the copper, by a pipe which cannot be seen in this section. The wort remains in the pan until the water for the succeeding mashes is discharged from the copper. But this delay is no lo of time, because the heat of the copper, and the steam arising from it, prepare the wort, which had become cooler, for boiling. The instant the copper is emptied, the first wort is let down from the pan into the copper, and the second wort is pumped up from the under-back into the upper 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. It is thus forced to blow up through the wort in the pan, and communicates so much heat to it, or water, called liquor by the brewers, that either is brought near to the boiling point. The different worts succeed each other through all the different ve els with the greatest regularity, so that there is no lo of time, but every part of the apparatus is constantly employed. When the ebullition has continued a sufficient period to coagulate the gro er part of the extract, and to evaporate part of the water, the contents of the copper are run off through a large cock into the jack-back K , below G , which is a ve el of sufficient dimensions to contain it, and provided with a bottom of cast-iron plates, perforated 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 , L , 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 , L , L , are very shallow ve els, built over one another in several stages: and that part of the building in which they are contained is built with lattice-work or or shutter flaps, on all sides, to admit free currents of air. When the wort is sufficiently cooled to be put to the first fermentation, it is conducted in pipes from all the different coolers to the large fermenting ve el or gyle-tun M , which, with another similar ve el behind it, is of sufficient capacity to contain all the beer of one day’s brewings. Whenever the first fermentation is concluded, the beer is drawn off from the great fermenting ve el M , into the small fermenting casks or cleansing ve els N , of which there are a great number in the brewery. They are placed four together, and to each four a common spout is provided to carry off the yeast, and conduct it into the troughs n , placed beneath. In these cleansing ve els the beer remains till the fermentation is completed; and it is then put into the store-vats, which are casks or tuns of an immense size, where it is kept till wanted, and is finally drawn off into barrels, and sent away from the brewery. The store-vats are not represented in the figure: they are of a conical shape, and of different dimensions, from fifteen to twenty feet diameter, and usually from fifteen to twenty feet in depth. The steam-engine which puts all the machine in motion is exhibited in its place, on the left side of the figure. On the axis of the large fly-wheel is a bevelled spur-wheel, which turns another similar wheel upon the end of a horizontal shaft, which extends from the engine-house to the great horse-wheel, set in motion by means of a spur-wheel. The horse-wheel drives all the pinions for the mill-stones b , b , and also the horizontal axis which works the three-barrelled pump k . The rollers a , a , are turned by a bevel wheel upon the upper end of the axis of the horse-wheel, which is prolonged for that purpose; and the horizontal shaft H , for the mashing engine, is driven by a pair of bevel wheels. There is likewise a sack-tackle, which is not represented. It is a machine for drawing up the sacks of malt from the court-yard to the highest part of the building, whence the sacks are wheeled on a truck to the malt-loft A , and the contents of the sacks are discharged. The horse-wheel is intended to be driven by horses occasionally, if the steam-engine should fail; but these engines are now brought to such perfection that it is very seldom any recourse of this kind is needed. IMG:4147767755307473660_illo0112.png:Section of fermenting house Fig. 104 enlarged (362 kB) Fig. 104. is a representation of the fermenting house at the brewery of Me rs. Whit bread and Company, Chis well Street, London, which is one of the most complete in its arrangement in the world: it was erected after the plan of Mr. Richardson, who conducts the brewing at those works. The whole of fig. 104. is to be considered as devoted to the same object as the large ve el M and the casks N , fig. 103. In fig. 104. , r r is the pipe which leads from the different coolers to convey the wort to the great fermenting ve els or squares M , of which there are two, one behind the other; f f represents a part of the great pipe which conveys all the water from the well E , fig. 103 , up to the water cistern F . This pipe is conducted purposely up the wall of the fermenting-house, fig. 104 , and has a cock in it, near r , to stop the pa age. Just beneath this pa age a branch-pipe p proceeds, and enters a large pipe x x , which has the former pipe r with inside of it. From the end of the pipe x , nearest to the squares M , another branch n n proceeds, and returns to the original pipe f , with a cock to regulate it. The object of this arrangement is to make all, or any part, of the cold water flow through the pipe x x , which surrounds the pipe r , formed only of thin copper, and thus cool the wort pa ing through the pipe r , until it is found by the thermometer to have the exact temperature which is desirable before it is put to ferment in the great square M . By means of the cocks at n and p , the quantity of cold water pa ing over the surface of the pipe r can be regulated at pleasure, whereby the heat of the wort, when it enters into the square, may be adjusted within half a degree. When the first fermentation in the squares M M is finished, the beer is drawn off from them by pipes marked c , and conducted by its branches W W W , to the different rows of fermenting-tuns, marked N N , which occupy the greater part of the building. In the hollow between every two rows are placed large troughs, to contain the yeast which they throw off. The figure shows that the small tuns are all placed on a lower level than the bottom of the great ve els M , so that the beer will flow into them, and, by hydrostatic equilibrium, will fill them to the same level. When they are filled, the communication-cock is shut; but, as the working off the yeast diminishes the quantity of beer in each ve el, it is nece ary to replenish them from time to time. For this purpose, the two large vats O O are filled from the great squares M M , before any beer is drawn off into the small casks N , and this quantity of beer is reserved at the higher level for filling up. The two ve els O O are, in reality, situated between the two squares M M ; but I have been obliged to place them thus in the section, in order that they may be seen. Near each filling-up tun O is a small cistern t communicating with the tun O by a pipe, which is closed by a float-valve. The small cisterns t are always in communication with the pipes which lead to the small fermenting ve els N ; and therefore the surface of the beer in all the tuns, and in the cisterns, will always be at the same level; and as this level subsides by the working off of the yeast from the tuns, the float sinks and opens the valve, so as to admit a sufficiency of beer from the filling-up tuns O , to restore the surfaces of the beer in all the tuns, and also in the cistern t , to the the beer in the tuns O O , a conical iron dish or funnel is made to float upon the surface of the beer which they contain; and from the centre of this funnel a pipe, o , descends, and pa es through the bottom of the tun, being packed with a collar of leather, so as to be water-tight; at the same time that it is at liberty to slide down, as the surface of the beer descends in the tun. The yeast flows over the edge of this funnel-shaped dish, and is conveyed down the pipe to a trough beneath. Beneath the fermenting-house are large arched vaults, P , built with stone, and lined with stucco. Into these the beer is let down in casks when sufficiently fermented, and is kept in store till wanted. These vaults are used at Mr. Whit bread’s brewery, instead of the great store-vats of which we have before spoken, and are in some respects preferable, because they preserve a great equality of temperature, being beneath the surface of the earth. The malt-rollers, or machines for bruising the grains of the malt, fig. 101. 102. , have been already described. The malt is shot down from A , fig. 103. , the malt-loft, into the hopper; and from this it is let out gradually through a sluice or sliding shuttle, a , fig. 103. and falls between the rollers. IMG:4147767755307473660_illo0114a.png:Conveyer screw Fig. 105. is the screw by which the ground or bruised malt is raised up, or conveyed from one part of the brewery to another. K is an inclined box or trough, in the centre of which the axis of the screw H is placed; the spiral iron plate or worm, which is fixed projecting from the axis, and which forms the screw, is made very nearly to fill the inside of the box. By this means, when the screw is turned round by the wheels E F , or by any other means, it raises up the malt from the box d , and delivers it at the spout G . This screw is equally applicable for conveying the malt horizontally in the trough K , as slantingly; and similar machines are employed in various parts of breweries for conveying the malt wherever the situation of the works require. IMG:4147767755307473660_illo0114b.png:Mashing-machine Fig. 106. is the mashing-machine. a a is the tun, made of wood staves, hooped together. In the centre of it rises a perpendicular shaft, b , which is turned slowly round by means of the bevelled wheels t u at the top. c c are two arms, projecting from that axis, and supporting the short vertical axis d of the spur-wheel x , which is turned by the spur-wheel w ; so that, when the central axis b is made to revolve, it will carry the thick short axle d round the tun in a circle. That axle d is furnished with a number of arms, e e , which have blades placed obliquely to the plane of their motion. When the axis is turned round, these arms agitate the malt in the tun, and give it a constant tendency to rise upwards from the bottom. turned by a wheel, w , fastened on the middle of the tube b , which turns freely round upon its central axis. Upon a higher point of the same tube b is a bevel wheel, o , receiving motion from a bevel wheel, q , fixed upon the end of the horizontal axis n n , which gives motion to the whole machine. This same axis has a pinion, p , upon it, which gives motion to the wheel r , fixed near the middle of a horizontal axle, which, at its left hand end, has a bevel pinion, t , working the wheel u , before mentioned. By these means, the rotation of the central axis b will be very slow compared with the motion of the axle d ; for the latter will make seventeen or eighteen revolutions on its own axis in the same space of time that it will be carried once round the tun by the motion of the shaft b . At the beginning of the operation of mashing, the machine is made to turn with a slow motion; but, after having wetted all the malt by one revolution, it is driven quicker. For this purpose, the ascending-shaft f g , which gives motion to the machine, has two bevel wheels, h i , fixed upon a tube, f g , which is fitted upon a central shaft. These wheels actuate the wheels m and o , upon the end of the horizontal shaft n n ; but the distance between the two wheels h and i is such, that they cannot be engaged both at once with the wheels m and o ; but the tube f g , to which they are fixed, is capable of sliding up and down on its central axis sufficiently to bring either wheel h or i into geer with its corresponding wheel o or m , upon the horizontal shaft; and as the diameters of n o , and i m , are of very different proportions, the velocity of the motion of the machine can be varied at pleasure, by using one or other. k and k are two levers, which are forked at their extremities, and embrace collars at the ends of the tube f g . These levers being united by a rod, l , the handle k gives the means of moving the tube f g , and its wheels h i , up or down, to throw either the one or the other wheel into geer. The object of boiling the wort is not merely evaporation and concentration, but extraction, coagulation, and, finally, combination with the hops; purposes which are better accomplished in a deep confined copper, by a moderate heat, than in an open shallow pan with a quick fire. The copper being encased above in brickwork, retains its digesting temperature much longer than the pan could do. The waste steam of the close kettle, moreover, can be economically employed in communicating heat to water or weak worts; whereas the exhalations from an open pan would prove a nuisance, and would need to be carried off by a hood. The boiling has a four-fold effect: 1. it concentrates the wort; 2. during the earlier stages of heating, it converts the starch into sugar, dextrine, and gum, by means of the diastase; 3. it extracts the substance of the hops diffused through the wort; 4. it coagulates the albuminous matter present in the grain, or precipitates it by means of the tannin of the hops. The degree of evaporation is regulated by the nature of the wort, and the quality of the beer. Strong ale and stout for keeping, require more boiling than ordinary porter or table-beer brewed for immediate use. The proportion of the water carried off by evaporation is usually from a seventh to a sixth of the volume. The hops are introduced during the progre of the ebullition. They serve to give the beer not only a bitter aromatic taste, but also a keeping quality, or they counteract its natural tendency to become sour; an effect partly due to the precipitation of the albumen and starch, by their resinous and tanning constituents, and partly to the anti fermentable properties of their lupuline, bitter principle, ethereous oil, and resin. In these respects, there is none of the bitter plants which can be substituted for hops with advantage. For strong beer, powerful fresh hops should be selected; for weaker beer, an older and weaker article will suffice. The hops are either boiled with the whole body of the wort, or extracted with a portion of it; and this concentrated extract added to the rest. The stronger the hops are, the longer time they require for extraction of their virtues; for strong hops, an hour and a half or two hours boiling may be proper; for a weaker sort, half an hour or an hour may be sufficient; but it is never advisable to push this proce too far, lest a disagreeable bitterne , without aroma, be imparted to the beer. In our breweries, it is the practice to boil the hops with a part of the wort, and to filter the decoction through a drainer, called the jack hop-back . The proportion of hops to malt is very various; but, in general, from a pound and a quarter to a pound and a half of the former are taken for 100 lbs. of the latter in making good table-beer. For porter and strong ale, 2 pounds of hops are used, or even more; for instance, one pound of hops to a bushel of malt, if the beer be destined for the consumption of India. During the boiling of the two ingredients, much coagulated albuminous matter, in various states of combination, makes its appearance in the liquid, constituting what is called the breaking or curdling of the wort , when numerous minute flocks are seen floating in it. The resinous, bitter, and oily-ethereous principles of the hops combine with the sugar and gum, or dextrine of the wort; but for this effect they require time and heat; showing that the boil is not a proce of mere evaporation, but one of chemical reaction. A yellowish-green pellicle of hop-oil and resin appears upon the surface of the boiling wort, in a somewhat frothy form: when this disappears, the boiling is presumed to be completed, and the beer is strained off into the cooler. The residuary hops may be pre ed and used for an inferior quality of beer; or they may be boiled with fresh wort, and be added to the next brewing charge. Figs. 107 , 108. represent the copper of a London brewery. Fig. 107. is a vertical section; fig. 108. , a ground-plan of the fire-grate and flue, upon a smaller scale: a is the close copper kettle, having its bottom convex within; b is the open pan placed upon its top. From the upper part of the copper, a wide tube, c , ascends, to carry off the steam generated during the ebullition of the wort, which is conducted through four downwards-slanting tubes, d d (two only are visible in this section), into the liquor of the pan b , in order to warm its contents. A vertical iron shaft or spindle, e , pa es down through the tube c , nearly to the bottom of the copper, and is there mounted with an iron arm, called a rouser , which carries round a chain hung in loops, to prevent the hops from adhering to the bottom of the boiler. Three bent stays, f , are stretched acro the interior, to support the shaft by a collet at their middle junction. The shaft carries at its upper end a bevel wheel, g , working into a bevel pinion upon the axis h , which may be turned either by power or by hand. The rouser shaft may be lifted by means of the chain i , which, going over two pulleys, has its end pa ed round the wheel and axle k , and is turned by a winch: l is a tube for conveying the waste steam into the chimney m . IMG:4147767755307473660_illo0116.jpg:Brewery copper Fig. 108 enlarged (41 kB) The heat is applied as follows:—For heating the colo al coppers of the London breweries, two separate fires are required, which are separated by a narrow wall of brickwork, n , fig. 107M , 108. The dotted circle a′ a′ indicates the largest circumference of the copper, and b′ b′ its bottom; o o are the grates upon which the coals are thrown, not through folding doors (as of old), but through a short slanting iron hopper, shown at p , fig. 107. , built in the wall, and kept constantly filled with the fuel, in order to exclude the air. Thus the lower stratum of coals gets ignited before it reaches the grate. Above the hopper p , a narrow channel is provided for the admi ion of atmospherical air, in such quantity merely as may be requisite to complete the combustion of the smoke of the coals. Behind each grate there is a fire-bridge, r , which reflects the flame upwards, and causes it to play upon the bottom of the copper. The burnt air then pa es round the copper in a semicircular flue, s s , from which it flows off into the chimney m , on whose under end a sliding damper-plate, t , is placed, for tempering the draught. When cold air is admitted at this orifice, the combustion of the fuel is immediately checked. There is, besides, another slide-plate at the entrance of the slanting flue into the vertical chimney, for regulating the play of the flame under and around the copper. If the plate t be opened, and the other plate shut, the power of the fire is suspended, as it ought to be, at the time of emptying the copper. Immediately over the grate is a brick arch, u , to protect the front edge of the copper from the first impulsion of the flame. The chimney is supported upon iron pillars, v v ; w is a cavity closed with a slide-plate, through which the ashes may be taken out from behind, by means of a long iron hook. IMG:4147767755307473660_illo0117a.png:Sluice-cock Fig. 109. represents one of the sluice-cocks, which are used to make the communications of the pipes with the pumps, or other parts of the brewery. B B represents the pipe in which the cock is placed. The two parts of this pipe are screwed to the side of a box, C C , in which a slider, A , rises and falls, and intercepts, at pleasure, the pa age of the pipe. The slider is moved by the rod a . This pa es through a stuffing-box, in the top of the box which contains the slider, and has the rack b fastened to it. The rack is moved by a pinion fixed upon the axis of a handle e , and the rack and pinion are contained in a frame d which is supported by two pillars. The frame contains a small roller behind the rack, which bears it up towards the pinion, and keeps its teeth up to the teeth of the pinion. The slider A is made to fit accurately against the internal surface of the box C , and to bear against this surface by the pre ure of a spring, so as to make a perfectly close fitting. IMG:4147767755307473660_illo0117b.png:Small cock Fig. 110. is a small cock to be placed in the side of the great store vats, for the purpose of drawing off a small quantity of beer, to taste and try its quality. A is a part of the stave or thickne of the great store vat; into this the tube B of the cock is fitted, and is held tight in its place by a nut, a a , screwed on with inside. At the other end of the tube B , a plug, c , is fitted, by grinding it into a cone, and it is kept in by a screw. This plug has a hole up the centre of it, and from this a hole proceeds sidewise, and corresponds with a hole made through the side of the tube when the cock is open; but when the plug c is turned round, the hole will not coincide, and then the cock will be shut. D is the handle or key of the cock, by which its plug is turned to open or shut it: this handle is put up the bore of the tube (the cover E being first unscrewed and removed), and the end of it is adapted to fit the end of the plug of the cock. The handle has a tube or pa age bored up it, to convey the beer away from the cock when it is opened, and from this the pa age f , through the handle, leads, to draw the beer into a gla or tumbler. The hole in the side of the plug is so arranged, that, when the handle is turned into a perpendicular direction, with the pa age f downwards, the cock will be open. The intention of this contrivance is, that there shall be no considerable projection beyond the surface of the tun; because it sometimes happens that a great hoop of the tun breaks, and, falling down, its great weight would strike out any cock which had a projection; and, if this happened in the night, much beer might be lost before it was discovered. The cock above described, being almost wholly with inside, and having scarcely any projection beyond the outside surface of the tun, is secure from this accident. IMG:4147767755307473660_illo0117c.png:Vent peg Fig. 111. is a small contrivance of a vent peg, to be screwed into the head of a common cask when the beer is to be drawn off from it, and it is nece ary to admit some air to allow the beer to flow. A A represents a portion of the head of the cask into which the tube B is screwed. The top of this tube is surrounded by a small cup, from which project the two small handles C C , by which the peg is turned round to screw it into the cask. The cup round the other part of the tube, is filled with water; into this a small cup, D , is inverted; in consequence, the air can gain admi ion into the cask when the pre ure within is so far diminished, that the air will bubble up through the water, and enter beneath the small cup D . The most efficient substance for fining beer hitherto discovered is isingla , which is prepared by solution in vinegar or old stale beer, and this solution is afterwards reduced with thin mild beer generally brewed for the purpose, in all large establishments, from a raw or return wort. It must next be pa ed through a fine hair sieve, by means of rubbing it down with a hard hair-brush, and brought to the proper consistency by thin mild beer. If properly made, it will be clear, transparent, and free from feculencies. Finings serve excellently to remove any extraneous matter that may be found floating in the beer, and thus changes it from bright to brilliant. The common quantity used is from a pint to a quart per barrel, according to the nature of the beer. To ascertain whether the beer is in a fit state for fining, put it into a long gla cylindric ve el, and add to it a teaspoonful, or thereby, of the fining; then give the mixture a good shake, by turning the ve el up and down, after closing its mouth with the palm of the hand. If the beer has been well brewed, its aptitude to become bright will be soon shown by the mixture getting thick and curdy; a bright portion will generally show itself at the bottom or middle; after which the finings will gradually mount to the top, taking up all the impurities along with them, till the whole becomes brilliant. Some have said that the finings should carry the impurities down to the bottom; but this, according to Mr. Black [8] , takes place only with stubborn beer, which would not become thoroughly bright with any quantity of finings which could be introduced. Finings have usually a specific gravity of from 1·010 to 1·016, and, when added to beer in a fit condition for fining, invariably go to the top, and not to the bottom. In fining beer in a barrel laid on its side, if the finings do not make their appearance at the bung-hole, the beer will not become bright. The isingla must not be di olved with heat, nor in hot water. [8] Treatise on Brewing, 8vo, p. 68. Beer brewed from imperfectly malted grain, or from a mixture of malt and raw corn, gives a fermentation quite different in flavour from that of beer from sound malt. The nose is, in fact, the best guide to the experienced brewer for ascertaining whether his proce is going on well or ill. Ropine is a morbid state of beer, which is best remedied, according to Mr. Black, by putting the beer into a vat with a false bottom, and adding, per barrel, 4 or 5 pounds of hops, taken gradually away after the first boilings of the worts; and to them may be added about half a pound per barrel of mustard-seed. Rouse the beer as the hops are gradually introduced, and, in some months, the ropine will be perfectly cured. The beer should be drawn off from below the false bottom. For theoretical views, see Fermentation ; and for wort-cooling apparatus, see Refrigerator .