Tuesday, 4 November 2008

Brewery equipment 1880-1914

Ever wonder how a late-19th century brewery was kitted out? No? Then you'd probably best skip this post. It discusses brewing kit in more detail than any sane person needs to know.

Today's source is "Principles & Practice of Brewing" by Walter J. Sykes & Arthur R. Ling, published in 1907. Though it's an expansion of an earlier book, published a couple of years earlier, authored by Sykes alone. It seems more reliable than some earlier brewing manuals. Though it wouldn't surprise me if it contained some dodgy science.

If you think Faulkner's theories on mashing are bollocks, you should see his explanation of fermentation. He manages somehow to combine the diametrically opposed theories of Pasteur and Liebig. The stuff about two much protein in beer being the cause of acetic production is pretty funny. He had a bit of an obsession with protein.

Before anyone brings it up, I'm aware that below I don't properly explain the working of a Yorkshire square, just its form. I haven't got to that bit yet.

In case you hadn't already noticed, I'm posting my research in near real-time. These are notes I took yesterday. Which is my excuse for the gaps and incomplete explanations. I like to think of this series as Study-along-with-Ron.

Layout of a tower brewery
This was the period of the tower brewery, a design which had developped during the course of the 19th century. The concept was to organise the layout in such a way so that the raw materials started at the top of the building and moved downwards in each successive stage in the brewing process by gravity rather than mechanical means. It also gave the brewery the smallest possible footprint, important in restricted city centre sites. The main disadvantage was that it was difficult to expand without major rebuilding.

Increasingly, breweries were purpose-built rather than being converted from buildings erected for other uses. There were architects that specialised in the design of breweries. Many of these sturdy and sometimes elegant structures still survive, though not all are still in use as breweries. My home town, Newark-on-Trent, has two such tower breweries from the late 19th century. One is now flats, the other shops.

Cold-liquor tank. A rectangular tank, made from cast-iron plates or sometimes wood, which was placed at the very top of the building. It supplied water for brewing and sometimes also for the attemperators, though it was better to use water directly from the well for the latter as it was generally cooler. When just used for brewing water, it needed to have a capacity of 2.5 barrels per quarter of malt used in a brew. When used for attemperator water too, it needed to be double that size.

Hot-liquor tank. A covered, cast-iron tank which was either rectangular or circular in shape. It was placed above the mash tun, for which it provided hot water. It was encased in wood or some other insulating material to prevent heat loss. The capacity was large enough to hold all the water for a brew, or about 6 barrels per quarter of malt used. Heating was effected by a variety of methods: injecting steam directly into the water through perforated pipes, by passing steam through a copper coil or by means of a high-pressure heater. The latter was a closed cylinder though which two inch diameter tubes passed. The space between the tubes and the cylinder was filled with high-pressure steam. A thermometer was fitted to the tank with its bulb in the water and the scale protruding outside so it could be easily read.

Malt-mill. This consisted of a pair of smooth iron or steel rollers which rotated in the opposite direction. The distance between the rollers could be very precisely controlled by means of screws. The idea was to crack the malt but not crush it into dust. The rollers were sometimes grooved. They were powered by a steam engine, via pulleys and belts. The rollers were fed by a hopper in the shape of an inverted pyramid suspended above them.

Grist case. Crushed malt was held in the grist case. This was usually directly below the mill and above the mash tun. When located away from the mill, the crushed malt was moved either by means of a Jacob's ladder or a screw. The upper part was square and the lower part in the form of an inverted pyramid. It was made from either smooth, well-seasoned wood or painted iron. A slide at the apex of the pyramid was opened to allow the grist to fall into the mash tun below.

Mash tun. Cylindrical in shape, these were made from a variety of materials such as wood, iron, copper, or wood lined with copper. Wooden tuns were tapered slightly at the top so the hoops could be hammered down to tighten the staves. Iron tuns were cylindrical and lagged with wood for insulation. Thick wooden covers were fitted to keep in the heat during mashing. A false bottom, made of copper, iron or gun-metal, was placed between 1.5 and 2 inches above the real bottom. For ease of removal, it was made in pie-shaped sections called "plates". The plates were either perforated or slotted. The holes were between an eighth and a sixteenth of an inch in diameter, spaced an inch apart.

Underback. A large open tank situated below the mash tun. The wort was run from the mash tun into the underback, from where it was pumped to the copper. It was important to prevent the wort from cooling so the underback was fitted with a steam coil. The wort was kept for as short a period as possible as, until it had been heated to 190º F in the copper, diastatic activity continued.

Mashing machines. There were two types of mashing machine: internal and external. Their purpose was to mix grain and water in the mash tun without the need for manual intervention. The rake mashing machine, an internal type, was invented by Matterface in 1807. A series of iron rakes rotated around a central axis, stirring the grain. It was quite a complicated piece of machinery with lots of moving parts. The first external mashing machine was invented by Steel in 1853 and devices of this type are still called Steel's mashers. It consisted of a screw encased in a closed metal cylinder. Water and grain pass through the cylinder on their way into the mash tun and are mixed together by the turning action of the screw. The cylinder was between 3 and 6 feet in length and 9 and 22 inches in diameter. The flow of grain and water could be regulated to get the perfect mix. It was powered by a steam engine via belts and a pulley. The great of this type of machine was speed - 200 quarters of malt could be mashed in just 20 minutes. There were various other patented mashing machines, but Steel's and the rake masher were by far the most common.

Underlet. This was a pipe leading from the hot-liquor tank to the bottom of the mash tun. Through it, hot water could be introduced to the mash tun from beneath the false bottom. Such hot water was called "piece liquor". It could be used either to adjust the temperature in the mash tun or to perform a simple step mash.

Steam coil. Another method of heating the mash was a copper coil placed beneath the false bottom through which steam was passed. Sometimes the coil was perforated so that stem could be introduced directly to the mash. Its use was similar to the underlet.

Steam plough. Fitted to the bottom of the rake shaft, this consisted of pair of hollow, plough-shaped vessels through which either hot or cold water could be added to the mash.

Sparger. This consisted of two or three perforated tubes called "Sparge arms" which rotated around a central axis. A cylindrical, copper reservoir placed at its centre which was connected via a pipe to the hot-liquor tank. Through the sparger, hot water could be sprinkled over the goods. The holes were all placed along one side of the arms so the the water escaping through them would cause the arms to rotate.

Copper. There were two types of copper: fire copper and steam copper. A fire-copper was heated directly by a furnace placed beneath it. A steam copper was, as the name suggests, heated by steam.

Fire-copper. I'll quote from Sykes and Ling here, as they describe the two main varieties of this type of copper so succinctly. The most common type was a "bench copper". "The lower portion is in the shape of an ordinary pan; at about half-way up it suddenly widens out a few inches, to form what is termed "the bench". From this the copper is continued up with parallel sides. The flues which surround the copper are only carried as far as the bench; consequently the portion above the bench, not being heated, has, to some extent, a cooling action on the wort, which tends to prevent boiling over." "The dome-copper is, as its name implies, covered in with a dome, round which there is a sort of tray, which has an outlet into the body of the copper. At the summit of the dome is a large opening, to which is attached a wide tube 1.5 to 2 feet in length. When the copper is boiling, the communication is left open between the tray and the copper, and through this the wort, as it boils out at the wide tube, after pouring over the sides of the dome and falling into the tray, finds its way back into the interior of the copper. When the wort has finished boiling and the heat is slackened, the plug fixed in its place, and a second batch of wort may be placed in the tray, which will be heated to some extent before being allowed to pass into the copper."

Steam-copper. These were cylindrical in shape with a domed bottom. Another cast-iron dome was fitted around the bottom, leaving a gap of about 3 or 4 inches into which high-pressure steam was pumped. It had several advantages over a fire copper. The heat could more easily be raised or lowered and it was more economical on fuel. Not being in direct contact with the furnace, it could be heated before the wort was added which consequently could be more quickly brought to the boil.

Hop-back. This was a wodden or iron container, through which the wort passed on its way from the copper to the cooler, provided with a perforated false bottom to hold back the hops. Some were circular in shape and fitted with a device similar to a sparger through which hot water passed to wash out any wort retained by the hops.

Cooler. This was a large but shallow vessel made of wood, iron or copper into which the wort passed after leaving the hop-back. It was located in a room with louvred window to allow air from the ouside to pass over it. The initial cooling of the wort took place here. By this time most breweries also had refrigerators which finished off the cooling process. The wort was not usually allowed to cool below 140ºF in the cooler for fear of infection. In addition to cooling, it also served to remove impurities from the wort, which settled to the bottom as a sludge. The cooler also served the purpose of hot aeration, that is the exposure of the hot wort to air. This helped the later clarity of the wort.

Refrigerator. This was a type of metal heat exchanger which finished the cooling of the wort down to pitching temperature. Cold water was passed through a series of horizontal copper tubes over which the wort flowed in a thin layer and was collected in a trough at the bottom. From the trough the wort was fed through a pipe directly into the fermenting vessel. There were several variations on this basic design, though all worked on the same principle. In breweries with an ice machine, refrigerated brine was used in place of water.

Fermenting vessels. There was much variation, both in materials used and method of construction, in the vessels used for fermenting wort. The most commonly used materials were wood, stone and slate. The vessels needed to have smooth surfaces which could be easily cleaned and which would not be damaged by the boiling water used in the cleaning process. The two basic types were "rounds" and "squares", named after their shape.

Rounds, much like barrels, were made of oak staves held together with iron hoops. Squares were made of wooden planks held together with iron bolts. The wood used was oak, American cedar or, most commonly, fir. Both were open-topped. Wort was filled to within two or three feet of the top, the rest being left for the head of yeast. A hole 30 inches square was cut just above the level of the wort to allow access to the inside. This was closed with boards when the tun was in use.

Yorkshire stone squares. These were traditionally constructed of slabs of hard stone, but increasingly slate was being used. The slabs were held together with iron bolts and cement was used to make the joints watertight. They had double walls and the space between was filled with water which acted as an attemperator. Slate versions usually had single walls and were fitted with a standard attemperator. Above the main chamber was a second stone vessel, called the "yeast trough", which was 24 to 30 inches deep. In the centre of its bottom a circular "manhole" 18 inches in diameter was cut. Around the hole was a collar of stone 5 inches high onto which a lid, also of stone, fitted. In one corner, a pipe (called the "organ-pipe) ran from the yeast trough down to just a few inches above the bottom of the lower vessel.

Loose pieces. These were casks used for cleansing. Usually puncheons holding around four barrels, they were placed on troughs called stillions in which the yeast escaping from the bunghole was caught. To stop the yeast just running down the side of the cask, a conical tin pipe was fitted into the bunghole. Another tin pipe stuck out from this at a right angle which was long enough the extend past the side of the cask. The yeast was expelled through the horizontal pipe, while the cask could be refilled through the vertical pipe.

Pontos. These were used in some London breweries for cleansing. After a short initial fermentation in rounds or squares, the wort was tranferred in pontos, barrels holding between four and six barrels. Here fermentation continued, with yeast forcing its way out through an opening in the head and into a slate gutter. This was going out of fashion and being replaced by the dropping system.

Burton Unions. This was a more sophisticated version of the loose pieces system of cleansing. Casks with a capacity of about four barrels were permanently fixed onto a wooden stand. A curved pipe called a "swan's neck" was fitted into the bung hole. Yeast was forced up through the pipe and into a long wooden trough (called the "yeast trough") which ran between two parallel rows of casks. At one end of the yeast trough was another vessel called the "feed trough". This was connected via pipes to a hole in the head of each cask and was used to keep them filled with beer. A tap at the bottom of the cask, opposite the bunghole, was used to remove the finished beer. This system was still being used by Bass until the 1980's. Marston's is the only remaining British brewery that ferments in unions.

Racking square. Beer wasn't usually racked into trade casks directly from the fermenters but first transferred to another tank called a racking square. Often they were very large in size, containing the equivalent of two complete brews. They were constructed of either slate or wood. Taps were placed a few inches above the bottom of the tank. Rubber hoses, with a metal nozzle at one end, were connected to the taps and used to fill casks.

Attemperator. The temperature of wort in fermenting vessels was controlled by an apparatus called an attemperator. It was a a series of tubes through which cold water was passed.

Rouser. Yeast was mixed into the wort by a simple device called a rouser. This was a flat piece of wood with a hole in the middle attached to a handle.

Aerator. These were used to aerate wort in the fermenting vessel. The simplest type of aerator was a weighted wooden cask with the heads removed and several holes in its sides. It was lowered into the wort on a rope and then quickly pulled out again. Powered devices included a pump which could draw wort from the bottom of the tun and spray it out above the surface. Operated in reverse, it could pump air directly into the wort.

Other vessels. Wort or syrup used for priming casks and caramel used for for colouring had to be kept in a special vessels, where the volume and gravity could be checked by excise officers. This was a legal requirement.

Casks. Trade casks were made of oak staves held together with iron hoops. The wood mostly came from the Baltic. Unlike on the continent, they were not lined with pitch so beer came into direct contact with the wood. Sometimes the wood become so badly infected with bacteria that they had to be discarded. That wood wasn't the perfect material for the storage of beer was aleready apparent: "Probably in the future some material which does not take up impurites so readily as wood will be employed in the construction of brewery cask, such as steel lined with tin, or wood with a lining of some indifferent metal."


The Woolpack Inn said...

It's a good job I'm not sane. Thank you, very interesting for a brewery nerd like me.

Ron Pattinson said...

As long as one person enjoys a post, I'm happy. In fact that's the secret of my sunny disposition: setting mu sights very low.

Andrew Elliott said...


I really enjoyed the description of the Yorkshire Squares (and especially the illustration)! I'm looking forward to your further discussion and descriptions of them.

Zak Avery said...

Ron, I might be asking the bleedin' obvious, but do you know how widely used Yorkshire squares were?

I've got a pic of one here, as the fermentation is subsiding. You can see the manhole, and the scum on the sides of the upper chamber show how high the foam got.

The little steel pipes are were the "rousers" are attached. In this instance, they are fan-shaped ends that actually pumps the beer over the foam, I guess to re-incorporate the yeast in the head back into the beer.

Ron Pattinson said...

Zak, common enough to get a long write-up in the book. Seeing as there are still quite a few breweries using them, I would guess pretty standard in parts of the North.

Unknown said...

Great read, one question I have regards how the false bottom's were (are) supported in these older style mash tuns, did they have a ledge the plates sat on ?

Ron Pattinson said...


I've no idea, to be honest.