Fermentation after WW II

In the immediate aftermath of WW II, most breweries still employed open fermenters. Either round or rectangular in shape. By this time they were usually constructed of metal or were at least metal lined.

Fermenters were fitted with attemperators – a series of metal pipes through which cold brine was passed. This was one of the huge innovations of the late 18th-century, allowing brewers to precisely control the fermentation temperature. It led to improved beer quality and the possibility to brew year round.

Many of the older systems of fermentation/cleansing were still in use.

Dropping System
Common in the South of England, in the dropping system two vessels were employed. The wort started fermentation in a tall, round fermenter and after a certain length of time – which could vary between 12 hours and 2 or 3 days, depending on the brewery – was dropped into a lower, shallow, square vessel.

The idea was to remove much of the yeast, which was either left in the upper round or quickly settled out in the lower square. This vessel was often called a “settling square”. The transfer between the two vessels also aerated the wort and reinvigorated the fermentation.

Yorkshire Square
As the name implies, this was popular in Yorkshire, but it was also extensively employed in the Midlands. There was a main square, usually made from slate but sometimes of metal, above which there was a second chamber. The fermenting wort was pumped to the upper chamber and then allowed to drain back down, leaving most of the yeast behind.

As with the dropping system, main purposes were to remove surplus yeast and to aerate the wort. Yeast used to operating in a Yorkshire square often struggles in a standard fermenter due to not being sufficiently roused.

There are still several breweries in the UK that employ this sort of fermenter.

Burton Union
This system was once common across the UK for brewing Pale Ales and wasn’t just limited to Burton. It is not, as people today seem to think, a fermentation vessel, but a cleansing vessel. Fermentation began in a conventional open round or square and the wort was only transferred to a union after a couple of days.

A union set is a series of linked casks. In the bung-hole of each cask there’s a swan-necked pipe through which yeast-laden wort rises and spills into a trough. The trough channels the wort back into the casks leaving the yeast behind. As with the other systems described above, it’s mostly about cleansing, that is removing yeast.


The above is an excerpt from my overly detailed look at post-war UK brewing, Austerity!

http://www.lulu.com/content/paperback-book/austerity/23181344

Which is now also available in Kindle format.

French brewing methods in the 1920's

I've been getting so distracted by hop statistics that I almost forgot about one of the best bits in the Journal of the Institute of Brewing article about the reconstruction of the French brewing industry after WW I. It's the bit where they describe French brewing methods. Probably the most relevant part for the theme of this blog.

In the part of Northern France most affected by the war, breweries only slowly started moving over to bottom fermentation after the end of hostilities. It really was a slow process, with many, even quite large concerns, not changing over brewing until after WW II.

Here are the three methods of fermentation used in France:

"The breweries in France work on three different systems:— Top fermentation, Mixed fermentation, Bottom fermentation.

Those in the devastated areas were practically all top-fermentation breweries and the majority were small concerns carried on in a primitive fashion. The beer is fermented in the actual trade casks or in puncheons at a high temperature and without any attempt at attemperation, it is fined with ray skins and sent out four or five days after mashing.

Bottom fermentation breweries are very exceptional in the north but are general in the east and at Paris where the largest French breweries are to be found.

"Fermentation mixte" combines some of the characteristics of both top and bottom fermentation. A top yeast is used and the fermentation method is more like that practised in England. There is, however, a short storage in casks similar to those in a Lager cellar but not chilled, and the beer is racked under counter-pressure through filters. The newer breweries are, however, fitted with open or closed fermenting vessels, the latter on the Landouzy system, very much like Yorkshire stone squares but made of wood. The cover is some little distance below the top of the round, and in the centre has a manhole through which the yeast works out, the beer running back into the vessel. They are said to give more body with light beers than open vessels, but the open vessels have many partisans particularly for stronger beers."
Journal of the Institute of Brewing, Volume 27, Issue 2, February 1921, pages 63 - 64.

Fermenting in trade casks was also typical of small-scale Belgian brewing. As was pointed out last time this type of fermentation came up, there were also British breweries who used this system. Bateman's, for example. Fermenting in casks without attemperation must have led to variable results. In a larger cask the temperature would rise more during fermentation than in a small one. Then, of course, there would be variations in air temperature at different times of year. Pretty much every barrel would taste different. There are still some Belgian styles, for example Saison, that are fermented at very high temperatures.

At this time only the largest French breweries bottom-fermented and few of those were in the north.

I'm not quite sure that I see how the third method described was "mixed fermentation". There wasn't even proper lagering at a cool temperature, as with Kölsch and Alt. Though I do recall in a report of a visit of British brewers to Cologne around 1900 there was a top-fermenting brewery described that lagered warm. Maybe this was more common in the past. It sounds like a way of emulating some characteristics of Lager without the need to install lots of expensive new cooling equipment.

That Landouzy system caught my attention. Was that somehow derived from Yorkshire squares or had they thought it up themselves? The aim seems the same: rousing the beer and removing suspended yeast.

"The old fashioned fermentation in puncheons with its crude and dirty methods is now being gradually abandoned, the new breweries are adopting one or other of the alternatives mentioned. Several of the larger concerns in the north are fitting up Lager plant either of the ordinary type or of the Nathan system of which one example already existed before war at Fere-en-Tardenoise, but which was destroyed during hostilities. But the great majority of firms are building top fermentation breweries with open or Landouzy vessels or adopting the "mixed" fermentation system. A few breweries have been fitted with mash filters and more are being adopted, while the Wooldridge system has been introduced, one large brewery to adopt it being in Armentieres, a name which brings to Englishmen many memories far apart from those of brewing, but among which the desire for beer may sometimes be recalled."
Journal of the Institute of Brewing, Volume 27, Issue 2, February 1921, page 64.

Mash filters seem to have been popular in France between the wars. I don't know, I find the idea very inelegant. I prefer the romance of the mash tun.

Here's proof of how common they were in France. This from a report of English brewers visiting the east of France:

"From the Ecole de Brasserie we proceeded to the Grandes Brasseries Reunies de Maxeville, where M. Dillon, the managing director, received us and piloted us through the various departments of this extensive brewery. Among the many interesting things shown us, three deserve special mention, namely, 1, the mechanical floor turner, which serves the six malting floors and displaces no less than ten trained maltsters. 2, The two large mash filters, capable of turning out 2,000 hectolitres (over 1,200 barrels) per day, and 3, the central control panel from which all the machinery can be started or stopped throughout the brewhouse, all valves opened and closed, and upon which are mounted the various pressure and vacuum gauges, registering thermometers, etc. This clever labour-saving contrivance was designed by M. Dillon."
Journal of the Institute of Brewing, Volume 30, Issue 8, August 1924, page 642.

These breweries were large and modern, unlike those in the North, and had already moved to bottom-fermentation. The brewery described here still exists:

" . . . the party proceeded to les Grandes Brasseries et Malteries de Champigneulles, there to see the largest and most wonderful brewery in France. Here the managing director, M. Krampitsch, conducted us round as much of the brewery as time would allow, and in this connection an apology is distinctly due to him that we should have had so little time to do justice to the many most interesting things which he had to show us. To an English brewer the brewhouse was simply a revelation, its many large coppers and other metal work being kept brightly polished, but the most imposing sight of all was the Buhler mash filter installation which was capable of dealing with 120 quarters four times a day. Altogether the spotless cleanliness reflected by the white enamel finishing of the whole room and the general air of light and brightness will linger in the memories of all those privileged to see it, for many a day."
Journal of the Institute of Brewing, Volume 30, Issue 8, August 1924, page 643.

Brewhouse at Champigneulles

You what we haven't had yet? A table. Time to put that right. Here's a comparison of French and UK beer production in the 1920's:

French and UK beer output (hl)
Year	France	UK	French output as % of UK output
1913	12,844,000	56,960,947	22.55%
1918	6,375,000	31,233,818	20.41%
1919	10,785,000	38,073,804	28.33%
1920	11,548,000	57,358,068	20.13%
1921	12,254,000	56,468,799	21.70%
1922	16,802,000	49,389,304	34.02%
1923	20,235,000	39,193,404	51.63%
1924	20,396,000	41,609,566	49.02%
1925	19,688,000	43,753,145	45.00%
1926	19,121,000	43,803,527	43.65%
1927	19,237,000	41,078,410	46.83%
1928	16,312,000	41,626,141	39.19%
1929	21,145,000	40,272,468	52.50%
Sources:
European Statistics 1750-1970 by B. R. Mitchell, 1978, page 285.
Brewers' Almanack 1928, p. 110
Brewers' Almanack 1955, p. 50
British Beer & Pub Association Statistical Handbook 2005, p.7

The development is quite different. In the UK, beer production shot up after the end of the war, but when the brief post-was boom ended, fell back again. While in France output rose steadily in the first half of the 1920's then stabilised. The French industry more than bounced back and after the war was  in better shape than it had been in 1913. In 1929, beer production was almost 40% greater than in 1913. While in the UK beer output fell by 30% over that period. And that's using bulk barrels. In terms of standard barrels the fall was even greater, due to the fall in gravities.

London vs Edinburgh system of brewing

Cleansing. The differences are all to do with the method of cleansing.

"In the fermenting rounds yeast is added to the wort, and the fermentation thus set up is allowed, in the Edinburgh system of brewing, to proceed for about four or five days, the temperature of the wort being kept within proper limits by the use of the attemperators or coils of pipes, through which cold water can be passed. During fermentation a portion of the saccharine matter in the wort is converted into alcohol, and carbonic acid is at the same time evolved. The reduction of the saccharine matter, or "attenuation," as it is called, is accompanied by a rise in the temperature of the wort, and it is this increase in temperature which has to be kept under control by the use of the cold-water pipes we have mentioned. When reduced to within two or three degrees of the required attenuation the contents of the rounds are run into the cleansing squares, where the beer deposits its yeast, becomes gradually cooled and fined, and in from twenty-four to thirty-six hours is fit to be drawn into casks, when hops are added to it, and it is stored or sent out to customers, as the case may be.

It is in the mode of conducting the fermentation, more perhaps than in any other portion of the brewing process, that the difference between the various so-called systems of brewing followed in this country exists. What is termed the Scotch, or, more properly, the Edinburgh system of brewing, which we have above described, is but the continuation or growth of a system of fermenting and cleansing began and practised on a small scale a long time ago. Formerly, the Edinburgh brewers used only the fermenting rounds, and cleansed from them direct into the casks sent out to their customers, the fermenting and cleansing or settling occupying from one to three weeks, according to the state of the weather and the quality of the ale. The ale so cleansed was quite "fine," and required no "topping up" in the casks. Now, however, the use of cleansing squares, such as those shown in our engravings last week, has become almost universal in Scotland, and, in fact, entirely so in the eastern parts; and the whole operation of fermenting and cleansing is completed in about a week. In the Edinburgh system the fermenting rounds are always kept of moderate dimensions or comparatively shallow; their capacity seldom exceeding forty barrels, or, if they are larger, they are made of such a diameter as to contain the required quantity of worts without the depth exceeding about 4 ft. This enables the temperature of the fermenting wort to be controlled with a moderate amount of refrigerating power.

The London system is in many respects the reverse of that practised in Scotland, the business of brewing being carried on in the metropolis on a gigantic scale, and the plant employed being large in proportion. Thus the fermenting rounds have been allowed to grow with the coppers, and quantities as large as from 600 to 800, or, in some cases, considerably over 1000 barrels are fermented in one tun, the depth being often from 12 ft. to 15 ft. With such large quantities the heat becomes uncontrollable, and subdivision into pontoons or their equivalents is a necessity. The "double square" system prevailing through the north and west of England is the same in principle as the old Edinburgh method. The double squares in which the fermentation is carried are, as it were, made by dividing an ordinary square at the middle of its depth, and making the upper part a yeast chamber, whilst the pumping of the beer from the lower to the upper square, and thus mixing it with the yeast to stimulate it, is somewhat analogous to the rousing of the yeast into the beer practised by the Edinburgh brewers for the same purpose. The Burton and some other English brewers follow the London subdividing system, but, instead of the pontoons or cleansing rounds, they employ the well-known "union casks." In the case of the Burton brewers it is the practice to stimulate the gyles with large proportions of yeast, and to thus bring about very much the same result as is obtained in London breweries by the large bulk contained in the fermenting rounds. There are, however, some other peculiarities connected with the Burton system, of which, together with special points in other systems, we shall speak in due course."
"Engineering, Volume 5 - from January to June 1868", 1868, page 464.

Wasn't that fascinating? Let's pick through the bones and see what meaty tidbits we can find to chew.

Originally in the Scotch, or Edinburgh system, fermentation and cleansing both took place in small rounds. No intermediate vessels were used between the rounds and the trade casks. However, by the time the article was written (1868) most Scottish brewers had introduced settling squares for cleansing. This sounds very much like the dropping system. Fermentation begins in a tall round fermenter and later the wort is dropped into a shallow settling square below (hence the dropping bit of the name) were fermentation is completed and the yeast settles out.

Except there's one big difference. In the dropping system as practised at Fullers and some other Southern breweries, the wort remained for only a short period in the round. Typical was 24 hours in the round and 5 or 6 days in the settling square before racking. In the Scotch system described above, the wort stayed in the rounds until fermentation was almost completed.

I'm sure that some of the differences were, as the author explains, due to the difference in scale between brewing in London and Scotland. As we've seen, the largest London brewers produced as much as all of Scotland. Their breweries had been designed to churn out enormous quantities of Porter and everything was on a grand scale. Even a comparatively small brewer like Fullers had fermenting vessels capable of holding more than 200 barrels.

Preventing the temperature of the wort seems a recurring theme. Hence the shallow Edinburgh rounds. Being shallow is probably also the reason why they'd been able to get away without using settling squares initially. Yeast will settle more rapidly in such a vessel. You could see this type of fermenter as a round and settling square combined. Looking at William Younger's brewing records from 1868, I can see confirmation of the small fermenter size. The largest wort I can find was 55 barrels. Most were 40-odd barrels.

I've just been taking a closer look at those Younger's records. And I think this text has helped me understand them better. Their worts spent 3 to 5 days in the fermenting tun and then 1 to 3 cleansing in a square before racking. The fermentation was in most cases, as the text says, within a few degrees of their final attenuation. Mostly just a couple of degrees (in SG). For example, 1036º to 1035º; 1030º to 1025º; 1017º to 1013º; 1017º to 1016º.

Part of a William Younger's brewing record from 1868 (document WY/6/1/2/21 at the SBA)

I think we all know what the "double square method" is: a Yorkshire square. Intriguing that this is likened to the Edinburgh system. Because, sure enough, there in Younger's records are the "beats" - beating the wort to rouse it. It had never occurred to me that this was the same concept as the continual rousing of a Yorkshire square. Which leads on to another question: what impact did this have on Scottish yeasts? Those used in Yorkshire squares had adapted itself to the constant rousing and wouldn't work well in a standard fermenter. Were Scottish yeasts the same?

Pontos at Watney's Stag Brewery in London

Pontos (called pontoons here) I think we all know about. They are a forerunner of union sets, basically large casks from which the yeast is allowed to escape through the top. The difference with unions being that the casks were upright rather than on their sides and needed to be topped up manually. The troughs and pipes of a union set effectively automated the topping up process. William Younger had unions of their own. Though these, in imitation of Burton, were only used for their Pale Ales.

Amazing, isn't it, how much you can learn from three paragraphs of text.

The three systems of fermentation 1880-1914

More laugh a minute stuff from "Principles & Practice of Brewing" by Walter J. Sykes & Arthur R. Ling, published in 1907. I wonder if I still have any readers left?

It's not surprising that the more labour-intensive methods described below have disappeared. Even the most sophisticated method of cleansing, Burton unions, is pretty fiddly.




The cleansing system
Probably having its origins in domestic brewing, this was the oldest method of fermentation. Originally, trade casks, that is the casks in which the beer was sent out to customers, were used for cleansing. After about 48 hours in the fermenting tun, the process of separating out the yeast began and the wort was transferred to trade casks. A few breweries still used this old-fashioned method in the early 20th century.

By the late 1800's, it was more usual to use large casks - butts, puncheons or pontos, each holding several barrels - for cleansing. These were known as "loose pieces" because, unlike the more sophisticated Burton Union method of cleansing, the barrels were not permanently fixed to a frame, but could be removed for cleaning. Yeast was pitched at 56º to 60º F and after 36 to 40 hours, when the temperature had risen to about 70º F and the gravity reduced by half, the wort was transferred to the cleansing casks. Splitting the wort into smaller volumes helped to keep down the temperature. If the temperature in the fermenting room was 45º to 50º F, the wort in the casks could get no warmer than 70º F.

In the summer, it was possible that the wort could become too hot so, as a precaution, it was moved to the cleansing casks earlier in the fermentaion, when it was cooler. Burton Unions were fitted with attemperators, so this was not necessary.

Some beer was expelled along with the yeast and it was important to top up the cleansing casks with clear wort. If they were not keep totally full, yeast would fall back into the beer and defeat the object of the operation. In some arrangements, such as Burton unions, topping up occurred automatically. In other cases, it was performed by hand, usually at intervals of around 3 hours.

As far as I am aware, the unions at Marston in Burton are the only remaining example of this form of fermentation.


The skimming system
This began exactly the same as the cleansing method. When the skimming point was reached, the wort was left in the fermenting tun but thoroughly roused. The yeast head was skimmed off every 6 hours. Temperature was controlled by means of attemperators. These were switched on when the temperature of the wort had reached 59º F and so regulated as to allow the wort to rise 1º F every 6 hours. The flow of water through the attemperators was increased when the wort hit 65º or 66º F to stop the wort warming any more. When the fermentation was nearly finished, the the water flow in the attemperators was increased even more to cool the wort down to 60º F.

Skimming stopped when it was estimated there was just enough yeast left to throw up one more head. This was checked by moving aside the head to look at the wort. If it was black and clear, it was ready and no more skimming was needed. If it was brown and opaque, it still contained too much yeast.


The dropping system
This was a variation on the skimming system developed by William Garton. When the wort had almost reached the skimming point, it was let down from the fermenting tun to a shallow settling square. The process of "dropping" both aerated and roused the wort. Much of the sediment was left behind in the fermenting tun.

Once in the settling square, the wort was skimmed and its temperature controlled by attemperators as in the skimming system.

Fullers were using the dropping system in 1910. They usually dropped the wort after just 12 to 18 hours in the fermenting tun. This is the record of a typical fermentation:


The temperatures match pretty much exactly those given by Sykes and Ling in their description of the skimming system.

Most London breweries employed either the cleansing system or skimming system. I am unaware of any brewery that still uses the cleansing system. There is at least one brewery (Refresh for the Brakspears beers) that continues to use the dropping system.


The stone square system
This method, as its alternate name "Yorkshire square" implies, was common in the north of England. It produced beers that were full-bodied and with a high CO2 content. A special type of slow-acting yeast, which needed a great deal of rousing, was used.

A small amount of yeast, just 1 to 1.5 pounds per barrel, was pitched at a temperature of 58º to 59º F. The yeast was mixed with a little wort in the upper chamber, thoroughly roused and then let down into the main chamber through the "organ pipe". The wort was then left undisturbed for 36 hours during which time the temperature rose to 62º F. For the next 12 hours, the wort was roused every two hours. Yeast rose through the central manhole and settled in the upper chamber.

The next stage was pumping. Wort was pumped into the upper chamber and mixed with the yeast that had settled there. The valve in the organ pipe was then opened to allow the wort and yeast mixture to run back into the main chamber. This process was repeated every two hours, starting with 15 strokes of the pump. On each subsequent repetition, the number of strokes was increased by 10. The wort was kept cool by the attemperating "jacket" formed bt the double walls of the square. Pumping ceased when the wort was within 1 or 1.5º of its finishing gravity.

After pumping was over, the yeast which rose into the upper chamber was removed any four hours. Any beer which had risen with the yeast was let back down into the main chamber through the "organ pipe". When all the yeast had been removed, the temperature of the beer was gradually reduced to 60º F. The manhole was then closed and the beer left to settle for 48 hours before being racked.

Yorkshire squares are the only one of the three fermentation systems still in widespread use. Breweries using them include Sam Smith's and Tetley's.

Fermentation 1880-1914

I'm still using "Principles & Practice of Brewing" by Walter J. Sykes & Arthur R. Ling, published in 1907 as my source. There's so much goodness in that book that I've had to split fermentation into two parts. Part two will be tomorrow.

Today we'll just be looking at the basics.

In case you're wondering, I've now got 75,000 words of the book done. Which is about half way. At 10,000 words a week, with a following wind I should have the bulk of it polished off by the end of the year. Then I just need to add the stupid jokes.




Fermentation
The amount of yeast for pitching was calculated based on the volume of wort to be fermented and its gravity, stronger beers requiring more. For a wort with a gravity of 1050 - 1055º, 1.5 - 2 lbs per barrel of yeast was needed; for a wort of 1066º, 2.5 to 3.5 lbs; and for worts over 1066º 3 to 4 lbs.

In 1910, according to their brewing logs, Fullers used much smaller quantities of yeast than those just quoted:

AK 0,65 lbs yeast per barrel
Brown Stout 0,94
Porter 0,44
PA 0,67
X 0,74

The yeast used had mostly been harvested from X, though in one case "Mann's Yeast" is specified.

Yeast was either added directly to the wort or first mixed with a quantity of wort at between 65 and 75º F to form a starter. The latter method was a better way of ensuring that a vigorous fermentation started as quickly as possible.

Weaker beers - those with an gravity in the range 1050 to 1055º - were pitched at 58-60º F and ideally not allowed to heat up past 66º F, 70º F at an absolute maximum. Temperatures any higher were too likely to lead to an infection. Strong beers were pitched a couple of degrees cooler and, protected by their higher alcohol content, could be allowed to rise to a maximum of 75º F.

The Fuller's logs from 1910 confirm these pitching and fermentation temperatures. All the worts were pitched at either 59 or 60º F and the maximum temperature reached during fermentation between 66 and 69º F.

If a fermentation were not vigorous enough and the yeast head discoloured, the solution was to "dress" the wort. The old method was to mix 1 lb of wheat flour and 4 ounces of salt per barrel into the wort and then rouse it thoroughly. When the problem was caused by too many unfermentable carbohydrates in the wort, this "dressing" could be effective. The diastase in the malt acted on the carbohydrates, making them more fermentable. The new method was to use just malt flour, without any salt.

The appearance of the head when through a series phases during fermentation:

- after 2-3 hours, bubbles of CO2 began to appear
- after 4-6 hours, a head formed around the edges of the vessel and gradually covered the whole surface
- as the head thickened, it entered the "cauliflower" stage
- next was the "rocky head" stage, when it reached a height of three or four feet
- after about 48 hours the had began to collapse and the "yeasty head" stage began, also known as the "skimming point" as this was when skimming began. It was also when yeast was harvested.

The appearance of the "yeasty head" was an indication that it was time to start cleansing or skimming, if either of these systems of fermentation were being used. The gravity had by now dropped to between a third and a half of the starting gravity.

There were three systems of fermentation:

- the cleansing system
- the skimming system
- Yorkshire squares


But you'll have to wait until tomorrow for a detailed explanation of the fermenting systems.

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."