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Rees' Cyclopaedia entry on Porter
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TranscriptRees’ Cyclopaedia (1819) Transcript of entry on “Porter” (from Vol 38; unpaginated) PORTER, a malt liquor, which is a favourite beverage of the inhabitants of London, and other large towns The dis- page break tinguishing characters of this liquor are its deep brown colour, and an agreeable flavour which it is difficult to describe, our language having so few words expressive of different tastes. The origin of the name is thus related by the ingenious editor of the Picture of London. “Before the year 1730, the malt liquors in general use in London were ale, beer, and two-penny, and it was customary for the drinkers of malt liquor to call for a pint, or tankard, of half and half, i. e. a half of ale and half of beer, a half of ale and half of two-penny, or half of beer and half of twopenny. In course of time it also became the practice to call for a pint or tankard of three-threads, meaning a third of ale, beer, and two-penny; and thus the publican had the trouble to go to three casks, and turn three cocks, for a pint of liquor To avoid this inconvenience and waste, a brewer of the name of Harwood conceived the idea of making a liquor, which should partake of the same united flavours of ale, beer, and two-penny; he did so, and succeeded, calling it entire, or entire butt, meaning that it was drawn entirely from one cask, or butt; and as it was a very hearty and nourishing liquor, it was very suitable for porters and other working people; hence it obtained the name of porter.” The house of Harwood is still a respectable brewery; but an immense trade has, since the period above-mentioned, arisen, and is divided among several brewers. At first, the only essential difference in the methods of brewing porter and other kinds of beer, was, that it was brewed from brown malt, and this gave to it both the colour and flavour required. Of late years it has been brewed from mixtures of pale and brown malt, and the colour of the present liquor is much less than was formerly esteemed requisite: but finding that pale malt yields a much greater portion of saccharine matter than brown, the greatest number of the London brewers have given up the brown malt altogether, using pale and amber malt, which is intermediate between the two. From these they procure a liquor of proper strength, and they give it both colour and flavour, by the addition of colouring matter made from burnt sugar, or by burning the sugar of concentrated wort. All the London porter is professed to be entire butt, as indeed it was at first; but the system is now altered, and it is very generally compounded of two kinds, or rather the same liquor in two different stages, the due admixture of which is palatable, though neither is good alone. One is mild, and the other stale porter; the former is that which has a slightly bitter flavour, from having been lately brewed; the latter has been kept longer. This mixture the publican adapts to the palates of his several customers, and effects the mixture very readily, by means of a machine containing small pumps worked by handles. In these are four pumps, but only three spouts, because two of the pumps throw out at the same spout: one of these two pumps draws the mild, and the other the stale porter, from the casks down in the cellar, and the publican, by dexterously [sic] changing his hold to the handle of the next pump, works either pump, and draws both kinds of beer at the same spout. An indifferent observer supposes, that since it all comes from one spout, it is entire butt beer, as the publican professes over his door, and which vulgar prejudice has decided to be the only good porter, though the difference is not easily distinguished. By referring to the article BREWING, our readers will obtain correct ideas of the general principles of the art, and under the present we propose to detail the process of brewing porter; and also to describe the utensils and machines used by the London brewers, who, in consequence of the very large scale on which they conduct their processes, have been induced to study, with the most minute attention, every thing which can tend to improve their beer, or economize [sic] the materials; as also to diminish the labour of removing such large quantities of liquor from one part of the works to another: in this their grand agent is the steam-engine, which gives motion to several very capital machines. There are in London twelve houses, which are considered as the principal porter-breweries, and from the returns of the excise, we find that the quantities of beer they brewed in the course of two years, viz. from July 1810 to July 1812, was as follows.
Of these works, the first that had a steam-engine, and the most complete in its arrangement of the utensils, is Mr. Whitbread’s in Chiswell-street. This gentleman having permitted our draughtsman to take drawings from the most interesting parts of his extensive works, we shall proceed to explain them, with the assistance of plate Porter Brewery. Figs. 1. and 2. of this plate are elevations of the whole brewery, being intended to shew the connection of all the parts at one view; but we must premise, that these elevations are in a great degree imaginary, and are not to be considered as taken upon any particular planes, because the different erections would then fall one behind the other, so as to hide them from the view; they are therefore represented in such situations as would be most convenient for explanation; but the relative levels, as also the dimensions of the individual vessels, are correct. A A, (fig. 1.) is the building containing the steam-engine, which is of twenty horses power, and gives motion to all the machines by a wheel on the axis of the fly-wheel, turning another upon the horizontal shaft, and this leads to the mill, where it turns the great horse-wheel B B. This wheel drives several other wheels, to convey the power in different directions. It was the original first mover of the mill; and when, (by the invention of Mr. Watt,) the steam-engine was rendered applicable to turn machinery, the horse-wheel was very judiciously retained, as by this means, if the engine should break, or be disabled, during the process of a day’s brewing, the work can be continued by putting the horses to the wheel. This is a great advantage, because the delay of a few ours in pumping up the beer, in more than one of the stages, would certainly produce a premature fermentation, and spoil the whole quantity. The water for the brewery is raised from a deep well by a pump placed in it, and this is worked by cranks and rods, b, from the beam of the engine. The well is situated out in the yard, and the cranks are placed in an arched passage, which leads from the engine-house to the well. The page break pump, by means of a pipe d, forces the water up to an immense reservoir, called the liquor back, placed at a sufficient elevation to supply the whole brewery. In fig. 1. this reservoir is represented as placed over the steam-engine, which indeed is its usual position in the large London breweries, but in Mr. Whitbread’s it is erected over some buildings which could not be shewn in our plate: from this the reservoir pipes are laid, to convey the water to any part of the works where it may be required. The principal of these are to the coppers B, of which there are three, placed close together, but only one can be seen. C is the chimney for it, and the same roof, D, covers them all. The water, being heated in the coppers, is conducted by a pipe, e, to the mash tuns E: one of these is placed immediately before each of the coppers, though only one is to be seen in the view. During the process of mashing, the malt is kept constantly stirred by machines in each tun, which receive their motion from the steam-engine by the shaft f: this passes over the centre of all three, and by means of bevelled wheels, gives motion to a vertical axis in the centre of each tun, which are the principal axes of the machines. The malt, previous to mashing, is ground, or crushed, to render the husks pervious to the water. In most breweries it is ground between mill-stones, such as are used for grinding corn, but in these works it is broken between iron rollers, g, g, similar to those used for flatting ion: they are 18 inches in diameter, and two feet six inches in length, and are situated at such a distance asunder, that only a piece of thick brown paper can be passed between them; they are turned by wheels from the long horizontal shaft a, and immediately above them is a third roller, which has a number of deep flutes, or cavities, cut in it, from one end to the other, and these, as it revolves, become filled with malt from the copper above, and then deliver it to the two rollers, which, being in motion, take it between them, and crush all the grains flat. By this, which is called a feeding roller, the supply to the rollers is kept constant and regular, without which they would be in great danger of clogging up, or setting fast. The malt, when it has passed through the rollers, is completely broken, even its most minute grains, but very little of it is cut into flour; for the husks of the malt, though cracked so as to admit the water readily to the contents, still prevent the flour being separated. This is a great advantage over the method of grinding, because that produces a great quantity of flour, which is the richest part of the malt, but when it is ground fine, and separated from the grain, it does not yield so much extract in the mash tun, as when it is preserved in the grain, and the husk sufficiently broken. This is because the flour, when immersed in the water, and wetted, forms a sort of paste, which at first absorbs a considerable portion of water, but will not afterwards quit it, so that very little extract is obtained from that portion of the malt which is separated from the grain, in the state of flour. The store of malt, before it is ground, is kept in the malt lofts over the mill, as represented. When it is brought in waggons to the yard, close by the mill, the sacks are drawn up by the tackle at F into the loft, and here the sacks are shot down, through holes in the floor, into the great store malt lofts, and from these, as it is wanted, is drawn out, through shuttles, into the hoppers of the rollers g, g. The store lofts extend much farther than we have been able to represent them in fig 1, but may easily be imagined, as they are only a repetition of eight or ten of those shewn in the figure, the same loft extending over the whole, and the same sack tackle drawing up the sacks from the carts in the yard; though this, of course, is not situated at the end of the mill over the pumps, but at the side, where it could not have been seen. The malt, after passing through the rollers g, g, descends into a chest, whence it is conveyed to the malt binns over the mash tuns E, by the motion of an inclined screw h: this is a wooden trunk or trough, in which the screw is fitted to revolve, and thus gradually pushes or raises the malt which is contained in the trough, from the lower end of it to the upper, which, being within the malt binn, and at the farther end of it, the screw completely fills, by distributing the ground malt at all parts of its length. The screw itself is formed of thin iron plates, bent into a screw , and fastened, by nails, to a central wooden axis, which revolves by the mill. When the malt is wanted for mashing, it is let down from the binn into the mash tuns, through sluices, or shuttles, in the bottom of it, and curtains are hung up all round from the binn to the edge of the tun, to prevent loss from the dust or flour of the malt flying in the air. After the process of mashing has continued a sufficient time, the extract or wort is drawn off from the mash tuns into other tuns, G, beneath, which are called the under-backs; here it remains only till the coppers are ready to receive it; and it is thrown up by the pump, H, into the copper-back I. This is a shallow cistern placed above the coppers, and from it the wort can be admitted into any of the coppers, or into their pans: these are vessels which are placed over the coppers, and their contents receive heat from the steam raised by the boiling of the copper itself. To understand this see fig. 3, which is a section taken through the centre of the copper. A A is the fire-grate, B B C the copper itself, containing 350 barrels; its top is a dome, and has a cylinder, G, rising up from it: F F is the pan, erected upon the top of the copper, and enclosing the dome C, within. The pan contains 250 barrels of liquor, which is heated by the steam rising into the cylinder G, and thence descending by pipes d, d, down into the liquor, and bubbling up through it. The heat communicated through the dome also assists in heating the contents of the pan. There are two valves in the head G, which are kept shut by steelyards and weights; but these being opened, the steam of the copper is allowed to escape through a copper pipe or chimney, K, (fig. 1.) into the open air. E (fig. 3.) is an iron door, to allow entrance, into the copper, and also to put in the hops; it is situated on the top of a cylinder rising from the dome, and is fitted so closely by grinding, that it is steam-tight when shut, and forced down upon its seat by a screw. Two flues proceed from the fire-gate at the farther end, and conduct the flame and heated air round in opposite directions, as shewn at D D, to the chimney, which is placed over the fire doors, and thus the heat is applied to the sides, as well as to the bottom of the coppers: this, as the figure shews, is made concave beneath, to allow a greater action to the fire. The chimney is open at the bottom, and, therefore, the draught it occasions though the flue is only by the lateral action of the current of air, occasioned by the column of rarefied air in the chimney; but this draught can be cut off, when it is required to damp the fire, by shutting up two iron doors at the ends of the flues, and then no air can pass through the fire. In some breweries, doors are provided to shut up the bottom of the chimnies, and thus increase the draught, by compelling all the air which enters the chimney to pass through the fire-grate, and thence by the flues into the chimney; this causes the copper to boil much quicker, but the violent heat soon destroys the copper at the bottom, by burning or melting it. When the hops are boiled in the copper, they are kept in constant motion, to prevent their lying upon the bottom and burning to it. This is done by a machine called the rowser, contained within the copper; it consists of a vertical spindle, e, in the centre of the copper, which at its lower extremity has a cross arm, g, curved, to correspond with the bottom, and page break from this a number of loops of heavy chain are suspended, to drag round upon the copper when the spindle is turned, and by this means the hops are raked over and continually disturbed. The spindle passes through a stuffing-box in the centre of the top, G, of the copper, and is turned round by a wheel f, engaged with another upon a shaft receiving motion from the engine. The direction of this shaft is shewn dotted in fig. 1, at x, but is there vastly extended in length, as is also the screw for the malt, because the engine and mill in reality stand in the line of the house containing the coppers and mash tuns, and at the end of them, in which position it would have been hidden by the building. The same shaft, x, also gives motion to the hop tackle, for drawing the hops up to the top of the copper, were they are thrown in at the door of it, E, fig. 3. The rowser can be drawn up from the bottom of the copper when it requires to be cleaned, for which purpose its spindle is suspended by a sort of tackle, that will quickly raise it up six or seven feet. The copper is provided with a float, to shew the height of the liquor within it: this consists of a strong wire, passing down through a tight stuffing-box in the top of the copper, and suspending a stone at the lower end of it: from the upper end of the wire a line is conducted over pulleys, which has a ruler or rod divided into feet and inches suspended from it, with a weight greater than the weight of stone when it is suspended in the liquor, but less than the weight of the stone when it is drawn up out of the liquor. In this situation the stone will always be at the surface of the water, in the same manner as if it floated, and will shew the height of the liquor in the copper. There are several pipes and cocks belonging to the copper, which are as follows: a pipe leading from the liquor back to introduce water into it; this has a cock formed of two passages, one admitting it to flow into the pan, and the other conveying it by a short pipe into the copper itself, and the handle being turned in one direction or the other, shews which way it will run, or turned in another direction it stops up the pipe; there is also a hole in the bottom of the copper back, through which the contents run down into the pan, but can be closed by a plug, and near it is a pipe leading down through the pan into the copper; this is closed by a valve, which can be opened by a lever and screw, when it is required to convey the wort from the copper-back into the copper itself; there is also a valve, which communicates at once from the pan down into the copper. From the bottom of the copper is a large cock with a pipe e, which runs horizontally over all the three mash tuns, and at every one a branch descends beneath the bottom of the tun, and turns up, with two or three smaller branches, leading into different parts of the bottom, by which means the hot liquor is admitted from the copper into the tun; it enters in different places at the same time, a precaution which is very necessary to distribute it equally through the whole of the malt in a tun, which like this is twenty feet in diameter; but to do this more effectually, the tun has a false bottom perforated with small holes; upon this the malt lies, and the water, being introduced beneath it, flows upwards through the holes in all parts at once. The mashing machine, (see an elevation of it in figs. 4. and 5.) is composed of several endless chains, R, extended over two wheels in the manner of chain pumps, and the links of the chains have rakes, d, fixed upon them, and as the wheels revolve, ascend and descend through the whole depth of malt contained in the tun, and thus effectually stir up the whole to incorporate it with the water. That this action may be performed in all the parts of the tun, the frame containing the wheels and chains is adapted to have a progressive motion round in the tun, by turning round upon the vertical axis, D, in the centre. This axis has a bevelled wheel, E, upon it, which tuns another upon the end of a horizontal shaft F, carrying the wheels, e, for the chains R, and extending from the centre of the tun to its circumference, that end being supported in a frame S, which rests with wheels upon the rim or edge, T, of the tun: the interior end is sustained by a frame S, (fig. 5.) fitted upon the vertical axis, D. Near the bottom of the tun another horizontal shaft, V, parallel to the former, is placed, an has upon it the lower wheels, e, for the endless chains of rakes. The pivots of this shaft are supported in the same frame S, as the upper: this being, as before mentioned, fitted upon the central axis, D, at one end, and the other end resting with wheels upon the edge, T, of the tun, it may be made to traverse round the tun. This is done by having a ring of cogs fixed upon the edge of the tun at T: and an endless screw, which is supported upon the frame S, engages the teeth. By means of bevelled wheels, l, this screw is turned slowly round from the upper axis, F, of the chain wheels; and it can, by means of a small handle, be disengaged from the motion, or it can at pleasure be engaged with either of two different pairs of the bevelled wheels, one giving it a slow motion and the other a much quicker; the first being used to traverse the machine round the tun till the malt is completely wetted, and then the quicker motion is used to mash the malt up thoroughly. This machine is the invention of Mr. Cooper, who had a patent for it, and has made great numbers. Several other ingenious machines have been invented, but are not yet in general use; one by Mr. Sylvester, another a patent by Mr W. Jones; (see Repertory of Arts, first series, vol. ix.); a very simple one by Mr Goodwynne, which he employs in his own brewery; a fifth kind of machine is described in our article BREWING. Mr. Jonathan Dickson has a patent for a method of making mash tuns in cast iron, by which the very heavy expences of constantly repairing, and often renewing, wooden vessels is reduced to a trifle. Messrs. Barclay and Perkins have one of these in use at their brewery. The mash tuns at Mr. Whitbread’s brewery are lined with thin sheet copper, applied in the same manner as the sheathing of a ship, to prevent leakage, and keep the vessel sweet and clean. The mash tuns are supported upon a framing of timber, as shewn in fig 1, which leave room within them for the under-back G. The malt-binns are supported over them by an assemblage of pillars between each of the tuns; and to give greater strength to the horizontal beams 1, which are beneath the binns, other horizontal beams, 1, are placed at a considerable height above them, and the two pairs being connected by framing and oblique braces, they form a truss frame similar to a roof, which will bear the weight of the binn, when full, without sinking. The pipe 3, which draws off the wort from the under-back, is conducted to the three-barrelled pump at H, which is worked by the mill: this elevates it to a trough which extends over the whole length of the copper-back I, and by means of a plug in the bottom the wort can be let down into it. When the wort has been boiled in the copper with the hops, both together are run off, at k, into the jack-back M: this is in reality a large strainer, to separate and retain the hops. It is a very large back, provided with a false bottom, composed of cast-iron plates pierced with small holes. Though these the liquor rains, when the pipe, l, from the bottom of the back is opened, and the hops are left upon the false bottom: the pipe, l, is conducted to the pump at H, and this raises the wort up to the same trough, over the copper-backs I; but instead of being run into these it is conveyed forwards, by a succession of troughs, and distributed into the different coolers N, N. These are large backs, and very shallow, several being placed in succession over each other, and the windows of the building are made very open, page break to admit a current of cold air, to carry the heat off from the beer. In these it remains a sufficient time, till it is cooled to the temperature desired, and then it is drawn off from the coolers into the fermenting house. This is a very large building, placed adjacent to the engine-house. A section of it is given in fig. 2: here p is the copper pipe, proceeding from the coolers (having numerous branches to all of them), to the gyle-tuns, or squares P, which are large open vats, of sufficient capacity to contain the beer of a whole brewing; here yeast is put to it, and the fermentation commences, and having continued a sufficient time, the beer is distributed into the small tuns, Q, called rounds, where the fermentation is concluded, and the yeast, as fast as it is produced, flows over by a spout into the troughs m, which are placed between every two rows: this cleanses the beer, by the separation of the yeast from it: and as by the division into small quantities, (for the rounds only contain nine barrels each,) the temperature is lowered, and as the disposition to fermentation gradually subsides, the beer becomes fit for storing in the vaults or under-ground cisterns T, that it may be kept, till by age it becomes fine and fit for the table. The squares P, (for there are two, one behind the other,) are 22 feet by 24, and 9 feet deep, so that their content is nearly 800 barrels each The pipe p, from the coolers N, (fig. 1.) has a branch proceeding to each square, and a double-passaged cock, 4, which will admit it into either, according as the handle is turned to one or the other. The pipe itself proceeds in an inclined direction to the bottom of the square, as shewn by the dotted lines, and thus introduces beer in the centre, by which means, if there is any variation of temperature in the contents of the square, and that which has recently entered, it will sooner be brought to an equality. Mr. Richardson, who conducts the brewing at Mr. Whitbread’s woks, has made an arrangement which deserves particular notice, and is worthy of imitation by other brewers. The pipe, p, is made of thin copper, and is enclosed within another pipe, the space between them being supplied with a stream of cold water. To effect this, the main ascending pipe, from the well to the liquor cistern, is not in reality carried up direct, as shewn by d, in fig. 1, but is placed in the angle of the fermenting house at d d, fig. 2. A branch, 5, proceeds along the wall thereof, then makes a turn, and joins the external pipe p: from the other end of this a branch is conducted to return the water to the main ascending pipe d, and in this there is a cock between the two branches, and another upon the branch: now the latter being shut, and the former open, the water ascends at once up the pipe from the well to the reservoir; but when the beer is to be drawn off from the coolers into the squares, the cock in the main pipe, d, is shut, and the other opened, which means all the cold water which the pump throws up from the well is forced through the space surrounding the pipe p, in which the beer flows, and thus cools it very effectually. To determine the temperature, the bulb of a thermometer is placed in the centre of the pipe, and its tube comes though it at 6; then a man is stationed to watch this, and when he observes it sink to the degree at which it is determined that the beer shall be left to ferment, he opens the cock and permits the beer to flow into the square; but still continues to observe the thermometer, and if it sinks lower he opens the cock wider, to admit the beer to flow quicker through the pipe p, that it may not be so much cooled by the flow of the cold water; or, if this is not sufficient, he regulates the quantity of cold water, by means of the cocks in the main pipe and the branch: on the other hand, if the thermometer indicates that the beer is not sufficiently cooled, the cock is closed a little; this retards the passage through the pipe, and lowers the temperature, by subjecting it for a longer time to the action of the cold water. By this simple contrivance, the brewer is at a certainty that his liquor has been put to ferment in the square or gyle-tun P, at the exact heat which he intended, a circumstance which was before very uncertain; because, being drawn from so many different coolers some would of course be less cooled than others, from their different situations, and it could only be guessed what temperature all these different degrees of heat would make when mixed together in the square, and the larger the scale of operation, the more uncertainty; because such large bodies of liquor take a considerable time to flow, and by passing such great lengths of pipes generally lose some heat; but it cannot be guessed how much. In Mr. Richardson’s method, this is accurately determined, and capable of regulation. A long thermometer is fixed in the sides of the squares, to shew the temperature of their contents, and this is found to increase during the fermentation; no yeast is removed from the beer in this stage, indeed scarcely an is formed, so though a very lag white head collects upon the surface, it is only light bubbles which instantly fall by the least agitation. The fermentation in the squares is generally concluded in thirty hours, and then the beer is removed to the rounds for cleansing from the yeast. It is first run off by a pipe 7, from the squares, into the filling up vessels R, R, which are in reality placed in the space between the two squares; but could not be so represented When these are full, the pipe is shut, and another cock, 8, opened, which permits the beer to flow through pipes 9, conducted beneath all the rounds Q, Q; and from these, cross branches are conducted between every two rows, and by short pipes introduce the beer in to the casks: thus they are all filled at once, and then the cock, 8, is shut. The casks are 240 in number, being arranged in sixteen of the rows which are seen in our figure, though only eight are drawn there; and each row contains fifteen of these casks. The troughs, m, between each pair of rows extend the whole length to receive the yeast produced from them, which in this stage of the fermentation is caused to slow off as fast as it is produced; and by this means it is that the fermentation is allayed, because the yeast which constantly keeps it going on, is not suffered to rest upon the surface of the beer. To render this effective, the rounds have close heads, and rather inclined to one side, where is a spout to conduct the yeast into the trough, therefore this spout is at the highest part; and there is no considerable surface exposed, upon which a head of yeast can float, to keep up the fermentation But as the rounds gradually diminish in content, they are filled up by fresh beer from the filling-up tuns R, which were previously filled as a reserve for that purpose. A pipe from the bottom of these enters into a small cistern S, where its orifice is closed by a valve. This is opened by a wire, which is connected with a lever, and a flat, which floats upon the surface of the liquor in the cistern; and this is, by means of the communicating pipes 9, kept at the same level with the surface of the beer in all the rounds; there being a free communication amongst them all. Now when, by the wasting of the yeast, the beer in the rounds sinks, the float in the cistern sinks, and opening the valve, admits a sufficiency of beer from the filling-up vessels to restore the level, and then the valve closes again. To prevent the beer in the filling-up vessels having an exposed surface, and to carry off the yeast from them as fast as it is produced, a moveable or floating head, 10, is adapted to the tun. This is a slightly concave pan, or dish, of plate iron, which has a pipe fixed perpendicularly down from the page break centre of it, and passing through the bottom of the vessel, in a stuffing-box. This dish floats upon the surface of the beer in the filling-up vessel, and as it is not quite so large as the inside of the tun, the yeast runs over in this space, and, falling down the pan to the central pipe, runs through it into troughs placed beneath, which convey it, in common with the produce of all the other casks, to a tank, or receptacle, sunk in the ground. From this tank the yeast is raised by a pump into casks, in which it is sent away , for the use of bakers, distillers, and others who employ it. Whilst remaining in the tank, a considerable portion of beer, which is drawn off by a pump, which the yeast carries over with it, drains away; and this is drawn off by a pump, which drawing from a lower level than the yeast-pump, raises the beer into a different cistern; and here it remains 48 hours, to ferment and cleanse itself. It is then pumped up into shallow settling backs, V, V, V: in the highest of these it remains some time to settle, and deposit any yeast it may contain, and is then drawn off into a second, and then to the third, by which it becomes clear, and is good strong liquor, though unpalatable; but being introduced into the square, at the same time with a succeeding brewing, it adds to its quantity, without injury of the quality. By this means, no waste takes place in any department of the work. When the beer has been sufficiently fermented, and the flow of yeast ceases, by which the brewers say it has sufficiently purged itself, it is drawn off from the rounds, Q, to be stored. That is done either in large tuns W, or otherwise in the cisterns, or underground vaults T: the former is the general system of the London brewers; but the latter, which is only practised at Mr. Whitbread’s, is undoubtedly the best method, because of the equality of temperature they preserve in both summer and winter; and their durability, compared with the wooden vats, is no small recommendation. Many breweries have wooden store vats of immense capacity, being as much as 40 feet in diameter, and 20 feet deep. They are placed upon timbers, and supported by pillars, that small casks may be kept beneath them; and the beer can be drawn off into these, when it is to be sent away from the works. The vaults, T, T, are arched, and lined with stone, well bedded in cement, or pozzolana, and the joints very carefully made. They were built under the directions of the late Mr. Smeaton; but the Roman cement, which has been discovered since his time, would be the best material for jointing and lining them.. A very superior cement of this kind, which is now manufactured in the north of Yorkshire, may be procured at Mr. Atkinson’s wharf, Narrow-wall, Lambeth, and would enable brewers, who choose to adopt the cisterns, to have them made perfectly tight; whereas in these works they had at first much difficulty, from the defective nature of the cement; though they have remedied this, by employing resinous substances in the joints. Each cistern contains 4000 barrels, and the store is thus kept without the loss of any room in the building; a great consideration in London, where the rent of premises is so high, not to mention the saving in the repairs, and renewal of the wooden vats. Mr. Richardson has applied a useful contrivance in this brewery, for cooling the beer previous to storing it in summer time: it is done by collecting the beer from the rounds, Q, into a cistern thirty feet square, sunk in the ground, and having a copper pipe conducted round its sides, making three turns in it: through this pipe a constant stream of cold water is conducted, in the same manner as before described, and this cools the beer to as low a temperature in summer as it will naturally have in winter, and then it is not liable to any fermentation in the store vats, which probably takes place in a slight degree in the ordinary process, and is one reason why beer brewed in the summer is seldom so fine as if brewed in winter. In this cistern the beer, being kept quiet and cool, deposits some sediment, apparently of farinaceous matter, which, if the slightest fermentation existed, would be held in the beer, and make it turbid; but here it seems to deposit more, and fine itself to a greater extent, in a very short time, than it would for a long period in the store vats; for we should observe, that one principal object of storing the beer is, that it may by age become fine and transparent, which it does by very slowly depositing the excess of vegetable matter, at the bottom of the vat, in the form of slime: but if the slightest fermentation is excited in the vat, it is put into an agitation, which wholly suspends this deposition, as long as it lasts; hence the great advantage which the brewers have found from employing such large vats as are not liable to sudden variations of temperature; and, for the same reason, subterraneous vaults are better than either. We have now described the whole of the brewery, excepting only the several store-houses for the hops and coals, of which very great stores must be kept, for such extensive works: the latter are kept in the lower parts of the buildings, in the vaults or arches upon which the coppers are erected, and any other convenient part of the ground floor; and, in like manner, the hops are stowed away in large bags, in the lofts over the malt stores, or any other parts. The number of the rounds, Q, in the fermenting house is not correctly represented in the drawing, nor the extent of the store vats W, which last, at Mr. Whitbread’s brewery, are situated in a large establishment on the opposite side of Chiswell-street. The managment [sic] of the brewing is thus conducted: A sufficiency of pale and brown malt, mixed, is broken between the rollers two or three days before it is wanted; and for this reason, the malt-binns are made large enough to contain 400 quarters of ground malt. Some kinds of malt, which, the brewers say, have too much fire in them, are found to improve by keeping some time after they are broken; but a few days keeping after they are broken will produce the same effect. The water is pumped up into the reservoir till it is full, and in this state the work begins, at two or three o’clock, by lighting the copper fires, and the engine fire, filling the coppers with water, and also their pans. The mash-tuns have the required quantity of malt let down from the binn, the curtains before mentioned being hung up to prevent the dust flying. All this is done by a few men, and the liquor (water) in the coppers is heated to the proper degree, which is generally about 150º for the first mash, its quantity being proportioned to the quantity of the malt, nearly in the proportion of two barrels to the quarter. But both these circumstances vary in different breweries, and from various causes, as has been explained under BREWING; though, we should observe, that the remarks there made, refer rather to the process of brewing on a small scale, than in the large way of manufacture; and though the principles are the same, the actual heats in the large way are much lower, because the loss of heat in the process is so much less in the large vessels The liquor being heated is turned on, that is, introduced into the mash-tun, by opening the cock, e, (fig. 1.) and admitting it to flow up through the malt, till in ten minutes time it has completely filled it: the mashing machine is now set in motion by the steam-engine, and works round the tun, with the slow motion for twenty minutes; then the quick motion is cast on for four minutes to complete the mashing; and after this it stands still for two hours to page break make the extract, and settle clear. The tap or cock into the under-back is now set running to drain off the wort, and this is left open, until the water for the second mash is sufficiently heated. This is the water which was at first filled into the pan; and immediately the first liquor quitted the copper, the contents of the pan were let down into it; and having acquired some heat while in the pan, is soon sufficiently heated, perhaps to 160º, and at the rate of one barrel to the quarter, being only half the quantity of the first mash, because so much of that is left in the malt. The mashing machine is worked for this as before, but it only stands one hour instead of two, because the malt was completely saturated before: in this period the first mash is pumped up into the copper, and the hops being added to it, the boiling is begun. The under-backs being thus cleared, the second wort is run off into them, and stands to drain from the malt, till the third liquor (water) is ready; this has been heating in one of the other coppers, till it is at 180º, and is then, in its turn, let down into the mash tuns, is mashed, and stands an hour, during which the second wort is pumped up into the copper back of the second copper, ready for boiling, and is admitted into the pan, that it may gradually heat. If a fourth mash is taken, that no waste may be made, it is heated in another copper, and is not brewed that day, but is reserved for the next brewing, and is then used instead of fresh water for the first mash. Some brewers do not practise this method, because there is in warm weather some danger of a premature fermentation, called foxing, taking place in the wort which is kept; but in cold weather it may be safely done, and is a saving. We have now to attend to the boiling: this is continued for the first wort one hour; and the second, being in the pan, receives considerable heat by the steam rising from the copper. When sufficiently boiled, the first wort, together with the hops, is run off into the jack-back M, and hence it is pumped up to the coolers N. The first wort is placed in these coolers, which, being least exposed to the air, will cool slowest, because the object is to get all the different worts cooled by the same time, ready for fermentation. The second wort is let down into the copper the instant the first is run off; and the hops which are left in the jack-back are filled into buckets, and drawn up by the hop-tackle, to be returned into the copper for boiling with the second wort; but as this continues for two hours, the third wort is thrown up, towards the end of the time, to the second copper, and the boiling begun; for the instant the second wort is distributed into the coolers, the hops are put to the third wort, and boiled with them for four hours. This boiling of the worts, coagulates great part of the solid matters which the wort extracted from the malt, and by thus collecting those minute particles which were before diffused so equally throughout the wort, as only to render it cloudy, into distinct fecula, they are disposed to deposit themselves in the coolers, which they do in great quantities; and it is by this process that the beer is first separated from the grossest part of the extract. The cooling is conducted as expeditiously as possible, and when sufficient, as shewn by the thermometer, all the three worts together are, as before explained, drawn off into the square P, which contains 800 barrels, which is the full quantity of a day’s brewing; the yeast is here put to it, and the fermentation begins, and it is by this process the porter acquires its spirituous quality, and is rendered clearer, from the great quantity of mucilaginous matter which is thrown off in the yeast. The fermentation first shews itself, by the whole body of the liquor teeming with innumerable small bubbles rising to the surface, each enveloped in a thin film of yeast, which, as the bubbles burst, collect into a head or froth, and float n the top of the liquor. The temperature of the fluid increases considerably, and the noise of these bubbles, rising through the fluid, causes a continual singing. Part of the bubbles bursts before they arrive at the surface, and the film of yeast which envelopes them, sinks until it is borne up again by the ascending bubbles. These films form at first a white covering to the surface of the beer, which the brewers call the lamb’s back, and as the process advances it becomes yellow, having the appearance of rocks; but this yeast is only a thin watery substance, which quickly melts down into a fluid. When the fermentation as advanced so far, that the head of the yeast begins to sink, it shews the process is past its greatest pitch, and the brewer must check it, or it would soon be succeeded by a second stage of fermentation, which produces vinegar. This check is given by the operation of cleansing, in which, as we have before stated, the yeast is carried off as fast as it is produced, and the fermentation gradually subsides. To review the several processes of the brewery of porter, it should be observed, that it is required, in the mashing, to extract from the malt all the saccharum it contains; but the heat at which this must be done is also favourable for extracting a great proportion of the mucilage and glutinous parts of the malt, which must afterwards, in some degree, be separated from the wort, and the portion which is left will determine the flavour and colour of the beer. If the heat of the mashing liquor is too low, it will extract so much of these matters, that all the subsequent processes can never separate them sufficiently to make the liquor fine; and at the same time it will not extract much saccharum. But by increasing the heat, the mucilage becomes, in a measure, coagulated in the tun, and is not extracted in so great a degree, whilst the saccharum is taken up by the wort in a full proportion. On the other hand, an excessive heat carries this too far, for it makes a complete paste of the malt, by melting the gluten, and the whole resembles a hasty pudding. This disaster, which the brewer calls setting the goods, spoils the whole process, as a great proportion of the water becomes combined with the malt, in the state of paste, and will not run off; whilst that proportion which does remain unmixed, and can be drained out, has extracted little or nothing, either of saccharum or gluten, from the malt. This state of things takes place, in a greater or less degree, whenever the extracting heat is taken too high: the other extreme we have spoken of. Between these the brewer endeavours to keep, and by his success in this simple point, the quality and strength of his beer will be influenced most materially. No precise rules can be given for the actual heats, as they depend on the nature of the malt, the heat used in drying it, (the brown requiring less heat than pale[sic]); the quality of the water has also its share, and the quantity of malt mashed at once, (because a great mash-tun loses less of its heat during the mashing than a smaller one); also the temperature of the atmosphere. Having been thus necessitated to extract more of the solid matters from the malt that he wishes to retain, the brewer, in the succeeding processes, turns his attention to the most effective means of expelling the superabundant mucilage, and without losing the sugar, to leave a fine transparent and palatable liquor. By the process of boiling, the grossest part of the mucilage extracted by the wort is coagulated, and in a manner precipitated into distinct fecula, leaving the liquor, which was before thick and muddy, comparatively clear between the flakes which are so large as to be individually visible. The boiling also extracts the bitter of the hops, which is necessary to make the beer keep, till it becomes fine and fit for the table; it also concentrates the wort, by evaporating a part of the water used in the mashing: on spreading the wort thin in the coolers, the fecula subsides, and is left behind. The fermentation in the squares, P, does not expel any of the extract matter, but the chief object of it is, to convert the saccharum into alcohol or spirit, and at the same time it disposes the grosser parts to a more favourable state for the separation which takes place in the second fermentation in the rounds, and by the great quantity of yeast which is thrown off, the beer becomes finer, at the same time that the production of spirit continues, and it loses its sweet taste. When this fermentation subsides, the beer is stored, and remains quiet, the longer time the better, to become clear and transparent; but this is provided the quantity of hops it had is sufficient to prevent its becoming sour, because the extract of the hop is inimical to fermentation, and prevents that process going on in the store vat, which, if it did, would produce vinegar What is really intended in the store vat is to deposit those finer particles of superabundant matter which have escaped the other processes, and the beer improves in its strength. The porter brewed for the supply of London is kept a very short time, and therefore as a small share of hops; and as it would not have time to become fine, it is fined by a process on purpose, which, indeed, is necessary; for if the beer was kept till it became fine, it would, by the shaking of carriage, when sent from the brewery, be rendered cloudy; the beer is therefore sent away in the rough, and requires fining, which is done by the consumer putting into the cask a small quantity of fining, sent by the brewer with the porter. These finings are made of isinglass dissolved in sour beer, made from the wort of the fourth mash, or sour beer obtained from the waste of any of the processes. A small quantity of this fining being put into the cask, precipitates the minute feculæ to the bottom, and soon renders the liquor quite fine. In Mr. Whitbread’s works no colouring matter is employed, as he uses a portion of brown malt; but most of the other brewers use pale malt, and colour the beer, by the addition of certain colouring matter, which being obtained from burning the same substance that causes the brown colour of the highly dried malt, produces a similar liquor, at a far less expence of materials, than when brown malt alone is used; because the pale malt yields a much greater proportion of saccharine matter than the brown, in which a share of the saccharum is burnt up in the kiln, only for the purpose of producing a colour and flavour which may so easily be communicated to the beer of pale malt, by a small quantity of burnt sugar. Many brewers, to avoid the censure of the public, who require them to use malt and hops alone, concentrate a quantity of their best first wort, by boiling it in an iron pan, and burn this instead of sugar, from which it does not materially differ. The process, in either case, is to put a quantity of coarse brown sugar, (or the concentrated wort,) into an iron pan, with a small quantity of water, keeping it constantly stirred up; it is then set on fire, and burnt for a few minutes, to give it the colour and flavour which might be obtained from brown malt. The fire is extinguished by putting on a cover The residuum is now mixed up with water to the consistency of treacle, and makes the colouring, which is put to the beer while working in the square, and gives it very near the same colour and flavour it would have derived from being brewed from brown malt. Some of our readers may have met with pamphlets professing to describe the process of brewing porter, and mentioning a variety of ingredients, such as liquorice, essentia bina, treacle, capsicum, ginger, lime, coriander seeds, cocculus indicus, &c. &c., but the writer of this article, having visited nearly all the great porter breweries in London, where he has been shewn into all their store-houses, and examined every process, can safely assure our readers that no articles more than malt and hops, except the colouring and finings, are used in their works, whose beer is reputed to be the best of any, nor has he ever met with any brewer who employs such articles for brewing porter. [End of transcript] Source file html/brewinghistory/transcripts/rees.html was last modified at 21:32, Sunday 22 February 2009 | ||||||||||||||||||||||||||||||||||||||||||