Saturday, 17 September 2011

Mashing technology in 1868

I estimate there are roughly seven people in the world interested in this stuff. Even I’m not interested in this. But Bailey unwisely expressed interest in an exposition of nineteenth-century mashing at George Younger’s that Ron posted, so he’s to blame for encouraging me to post this even more detailed description.

I can’t visualise these machines from the descriptions at all. Thank Christ for pictures.

From Engineering, 26th June 1868:
BREWING AND BREWERIES.—No. XIV.
Apparatus Employed In The Process Of Mashing—(continued).

Formerly the method of mixing together the malt and liquor in a mash-tun was by the use of “oars,” or wooden stirring rods, and this method of forming the mash is still adopted in the case of very small breweries. Where mash-tuns of more than a very moderate size are employed, however, the adoption of such a mode of mashing would not only involve a severe amount of labour, but it would produce a most unsatisfactory result. It is desirable to employ such appliances for mashing as will effect the thorough mixing of the hull and flour of the crushed malt with the liquor, and will leave the goods in a porous condition, so that they may be readily penetrated by any further amount of liquor sparged over them or otherwise added. One of the earliest forms of mashing machine, and one that is still in use in many old breweries, is that consisting of a radial frame which travels round in the mash-tun, this frame having two horizontal shafts, one above and slightly in advance of the other. Each shaft carries a number of chain wheels, and over these work chains fitted with transverse teeth or rakes. As the shafts revolve the teeth on the chains are drawn up through the goods, all parts of the latter being successively acted on as the frame carrying the shafts travels round the tun. At Messrs. Barclay’s all the mash-tuns but one are fitted with chain rakes of this kind, and they are also in use at Messrs. Reid’s and other London breweries. At Messrs. Barclay’s the chains used to consist of cast-iron links connected by wrought-iron pins, but these links used to fail frequently — rather an awkward matter if the failure occurs in the middle of a mash — and Mr. Beckwith, the engineer, is now making them of malleable cast iron.

At Messrs. Reid’s, where there are four mash-tuns, each capable of mashing 160 quarters, the mashing machine in each tun is double, or, in other words, instead of the frame carrying the chain wheel shafts, being merely a radius of the tun, it extends across the whole diameter. By this arrangement the goods are turned over twice during each revolution made by the frame, and the mixing is thus effected more quickly than it otherwise would be. In slow gear the frame makes a complete revolution in fifteeen minutes, whilst in quick gear it completes the circuit in ten minutes, the speed being equivalent to one revolution in five minutes with a single machine. In Messrs. Reid’s machines the rake chains are of wrought iron throughout, and we are informed that the apparatus is found to work very satisfactorily.

The “porcupine”
An improvement on the chain rakes is the so-called “porcupine” machinery, which has, perhaps, been more extensively adopted than any other form of mashing apparatus. Of an example of this form of mashing machine we gave an engraving on page 532 of our number for the 29th of May last, our illustration representing a vertical section and plan of one of the cast-iron mash-tuns at Messrs. Truman’s brewery, which mash-tuns we may mention, are all, with one exception, also fitted with Steel’s masher, which we shall describe presently. The mashing apparatus of which we are now speaking, consists, as will be seen, of a series of rakes carried by curved arms fixed to a pair of horizontal shafts placed one above the other; the rakes being arranged so that, as the shafts revolve, they pass each other and thoroughly turn over the “goods” in the mash-tun. The inner ends of the horizontal shafts are carried by plummer blocks attached to brackets which encircle the central vertical, or driving, shaft, the lower end of which latter shaft rests upon a suitable bearing at the bottom of the mash-tun. The outer ends of the rake shafts rest in bearings carried by a kind of frame, which is connected by tie bars with the brackets encircling the central shaft, and which is supported by a pair of rollers which bear on the rim of the mash-tun. The upper part of this frame also carries bearings for a pair of shafts, which are geared together, and each of which has, running loose on it, a pinion which gears into a rack formed round the edge of the mash-tun. Each shaft, also, carries a sliding clutch for connectiug it to its pinion, and these clutches are both worked by one lever, arranged as shown in the plan, so that either can be thrown in gear at pleasure, but so that they cannot be engaged simultaneously. One of the pinion shafts extends inwards towards the centre of the mash-tun, and at its inner end it carries a bevel wheel, which gears into a bevel pinion on the central shaft, this pinion being about one-third the size of the wheel. The rake shafts also carry bevel wheels, which gear into equal sized wheels on the vertical shaft, the pairs of wheels being arranged so that the two rake shafts are both made to revolve in the same direction.

The action of this apparatus will be readily understood. From the vertical shaft motion is communicated to the rake shafts, and a slower motion to one of the shafts carrying a pinion gearing into the circular rack. From this shaft a still slower motion is communicatcd to the other short shaft, carrying a pinion gearing into the rack, the two shafts being geared together by wheels of unequal sizes. It will thus be seen that when one of the rack pinions is thrown into gear with its shaft by means of its clutch, the whol apparatus will be made to travel slowly round the mash-tun, and the rakes will thus be brought to bear upon the whole of the “goods.” The direction of the motion of the apparatus, and the speed at which it is caused to travel, will depend upon which pinion is thrown into gear. This arrangement of travelling gear is similar to that adopted in the case of the chain rakes already spoken of.

The mashing apparatus above described has, as we have said, been very largely adopted; it being in some breweries used by itself, and in others used in addition to a separate mashing machine, such as Steel’s. In most cases the arms and teeth of this class of machinery are, as at Messrs. Truman’s, of wrought iron; but in some instances the teeth are made of wood, and in others, as at Messrs. Bass’s brewery at Burton, both the teeth and arms are of wood, the latter being fitted into sockets cast on the shaft, which are of gun metal. At the City of London Brewery, where mashing machines of this kind are in use, the central shafts are fitted with teeth, which act upon the central portion of the goods not touched by the revolving rakes ; and at Messrs. Charrington’s, where there are three mashtuns 18 ft. in diameter, and capable of mashing 100 quarters each, and where these “porcupine” machines are also used, the rake shafts are made to extend across the whole diameter of the tuns, as in the chainrake machines at Messrs. Reid’s, which we have already mentioned. The large mash-tun at Messrs. Hoare’s, which we have mentioned in a previous article as being capable of holding a mash of 190 quarters, is also fitted with porcupine machinery, the gear being arranged so that the machinery can either traverse round at a slow or quick speed, or the rakes worked without shifting their position in the mash-tun. In quick gear this mashing apparatus makes the circuit of the mash-tun in two minutes—a very high speed. In some machines of this kind, as, for instance, in those at the Well-park Brewery, Glasgow (Messrs. J. and R. Tennant’s [sic]), the circular rack, in which the pinions giving the travelling motion gear, is placed within the tun, instead of around its upper edge, the object of this being to avoid the chance of men employed about the mash-tun being caught and injured by the gearing.

Another arrangement for stirring the goods within the tun is that shown in the section of the mash-tuns at Messrs. Miller’s brewery, at St. Petersburg, which we published last week. In this instance a central revolving shaft carries two curved arms, which work close to the false bottom of the mash-tun, and which, therefore, act upon the lower portion of the goods only. In this case the mixing of the malt and water is effected by a Steel’s masher before the goods enter the tun. It may be noticed that at Messrs. Miller’s brewery the central shafts of each mash-tun can be thrown into or out of gear by means of a pair of friction discs neatly arranged as shown in the engraving.

So far we have only spoken of contrivances for effecting the operation of mashing within the mash-tun itself; but of late years a large proportion of our brewers have become convinced that it is better to effect the mixture of the malt and liquor in detail as they enter the mash-tun than to deal with the goods in a mass, as was formerly the universal practice. The consequence has been the adoption of separate mashing machines, and the best varieties of such machines we shall now proceed to describe.

Steel’s masher
The masher which may be termed the parent of efficient machines of this class is that invented and patented by Mr. James Steel, of Glasgow, and it is one which has probably been more extensively adopted than any other. Of this machine, the manufacture of which has been taken up by Messrs. E. A. Poutifex and Wood, the well-known brewers’ engineers, of the Farringdon Works, Shoe-lane, we gave an illustration on page 540 of our last number but two. As will be seen by our illustration, this masher is of exceedingly simple construction. It consists merely of a cylindrical casing, within which revolves a shaft provided with a number of radial arms. The casing is open at one end and closed at the other, the shaft passing through a stuffing-box at this closed end, and being provided, outside, with fast and loose belt pulleys. The grist and liquor are admitted to the casing by branches at the closed end, and as they pass through to be delivered into the mash-tun from the open end of the casing, they are thoroughly mixed together by the action of the arms on the revolving shaft. The branch through which the malt enters is fitted with a regulating slide as shown, and both the main casing and branch are fitted with hand-holes which give access for cleaning, &c. The water branch is not shown in our engraving; it communicates with the side of the casing, and is fitted with a cock.

Ou page 462 of our number for May 15th last, we gave an engraving which included a Steel’s masher, as it has been applied at Messrs. Miller’s brewery at St. Petersburg. In this case there is no slide for regulating the supply of the malt, the latter being received direct from a small hopper placed below the malt-mill. The casing of the masher, instead of being cylindrical, tapers slightly in its diameter, being reduced towards the end from which goods are delivered into the mash-tun; and in order still further to delay the progress of the mash through the machine, the central shaft is fitted at intervals with flat arms, or oars, in addition to the usual circular ones. The liquor is delivered into the casing from the branch, through two openings diametrically opposite each other, these openings communicating with a passage cast around the branch, as shown. Arrangements are made for admitting either hot or cold water through the openings, as may be desired. The central shaft of the masher, it will be noticed, is in this case driven by bevel gearing, which connects it with the shaft, n, on which the belt pulleys are placed, and which also carries a flywheel, o.

In a great number of instances Steel’s mashers are used alone, or, in other words, the whole of the mashing is effected by them; whilst in other cases they are used in combination with other mashing apparatus placed in the mash-tun. As instances, we may mention Messrs. Salt and Co.’s, of Burton-on-Trent, and Messrs. Mann, Crossman, and Paulin’s, as establishments where the former mode of working is adopted, whilst at Messrs. Truman’s, at Messrs. Allsopp’s, and at a number of other breweries, Steel’s mashers are used in addition to the ordinary “porcupine.” Where Steel’s or other separate mashers are alone employed, it is the practice to make but one mash, and to sparge the remainder of the length; whilst where mashing appliances are also provided within the tun, a series of mashes may be made, the goods being turned over during each mash.

Colyer’s malt feeder
In order to ensure a steady supply of malt to Steel’s mashing machine, and thus still farther guard against “balling,” Messrs. F. Colyer and Co., of Leman street, have designed the arrangement of a malt feeder, of which we annex an illustration. This feeder is placed between the grist shoot and the mashing machine, and it consists of a casing containing a drum, A, which, has an oscillating motion imparted to it by an eccentric, C, fixed on the central shaft of the mashing machine. On each side of the oscillating drum are flaps, D, the position of which regulate the quantity of malt passing through; the drum, A, as it oscillates, leaving an opening between it and each flap alternately.
Interesting that the author notes that where Steel’s masher is used, they only mash once and then sparge. Did the Steel’s masher contribute to the spread of sparging?

Also interesting to see what kit the well-known breweries were using. Barclays and Reid’s had chain rakes.

The most popular was the “porcupine” masher. Truman’s had these as well as Steel’s mashers. Bass, Charrington, Hoare and Tennent all used them.

Salt relied solely on the Steel's masher, as did Mann, Crossman and Paulin.

Ron’s post pointed out that George Younger had three mash tuns of 100 quarters each. That was the same size as Charrington twenty years earlier. Reid’s could mash 160 quarters at a time in each of four mash tuns.

I haven’t been paying attention. I didn’t realise James Steel, the inventor of the mashing machine, was from Glasgow. He must be the James Steel of Steel Coulson brewery.

5 comments:

  1. I'm afraid I am still finding this interesting... possibly because this is the kind of stuff we should already know. Our basic beer education has been sadly undisciplined and partial.

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  2. Make that 8 people (unless you counted me as one of the initial interested 7...)

    Fascinating stuff,

    Kelly

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  3. Kelly, you will be glad to hear that the article is one of a series on brewing technology. AND I AM GOING TO POST THEM ALL EVEN IF THERE ARE NO READERS LEFT ALIVE BY THE END.

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  4. It was actually William Steel who invented the Steel's masher not his brother James - see the record in the London Gazette of 21st March 1854 regarding the invention of 11th November 1853. William operated a brewery in West Barns (now in East Lothian) as William Steel and Son.

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  5. Poutifex and Wood installed 3 coppers at The New Culverden Brewery of E & H Kelsey Tunbridge Wells, Kent. 1878.
    Possibly a Steels masher as well.

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