Wednesday, 3 February 2010

Barclay Perkins fermenters (ca 1900)

As promised, Barclay Perkins fermentation details.

First, RDP (a Porter of some sort) from 1899:

This looks pretty straightforward to me. No sign of dropping. Then fined and racked at the end.

Next X Ale from 1906:


 This more complicated. The three entries at the very top are of interest:

Slates 6 m 6 4.8 @ 62 1/2
Wood Skim 6 m 8 4.6 @ 63
Cop. do 6 m 10 4.6 @ 63 1/2

6 m 6 = 6th 6 AM [date and time]
4.8, 4.6 = gravity in pounds per barrel [attenuation of the wort]
@ 62 1/2 = 62.5º F [temperature of wort]

I'd be interested in what you make of that. I won't influence you with my opinion.

And finally XLK from 1919:


Here you can see the use of the attemperator. "Liquor on" means running cooled water through the attemperator pipes. The bit on the bottom right is informative. It gives the numbers of the fermenting vessels followed by SB's, SK Wood, SK Copper. What do you reckon that means?

Here's another I've just found which clarifies some points:

If you look in the bottom right hand corner you can see that two different actions were carried out on Trade XLK. FV numbers 6 and 22 were cleansed, FV 19 skimmed. Which implies that the SB FV's weren't fitted with skimming parachutes.

I wonder if there are any plans of the brewery in the archive?


Gary Gillman said...

Slates means fermenting squares made of that material (I believe blue slate was used). Wood skim means that a wooden device was deployed on the surface to skim the yeast. "Copper do" probably refers to a copper vessel into which the skimmed beer was transferred or dropped. The attenuation was proceeding but slowed after the skimming, which makes sense.


Gary Gillman said...

Here from Spon is a description of processes similar in some cases to what BP were doing at this time. It is evident from this and other period descriptions that variations were practiced at different breweries. Some used parachutes of different designs to vent yeast, others skimming as at BP in this period. In some cases the yeast was sloughed into copper-lined vessels. However in the instant case, I interpret it that the beer was transferred after skimming into a copper vessel of some kind, possibly an old boiling copper. Perhaps it was held there before racking whereas the fermenters were refilled for their primary duty.


Ron Pattinson said...

Gary, I believe slate, wood and copper refer to three different designs of fermenting vessel. It's easiest to see this in the third example where it gives the FV numbers.

Gary Gillman said...

Maybe, perhaps a skimmer was used for the wooden fermenter and some other way (parachutes probably) for the metal vessels. Still, it's an odd use of the term skim in "wood skim" and I think it is possible that the beer was being described after skimming from the slates.


Gary Gillman said...

Okay I think I see now what it is. There are three types of fermenters (I was aware of this implication from the bracketed sentences in the other entry stating what goes to the trade and what is bottled). Gravity and temperature are tested in the slates uncleansed; in the wooden vessel they are tested after skimming; and in the copper vessel they are tested after skimming also, that is what the "do" means.


Ron Pattinson said...

Gary, just added another image to the post. It makes some things clearer.

Gary Gillman said...

Okay thanks but based on my reading, skimming and parachutes were technically different. Skimming was where a wooden oar was moved across the spume of yeast to drive it down spouts at the edges of the vat. Wooden vats (an older technology) often received this treatment.

Parachutes were a later development, they were a stem-like pipe that came up through the bottom of the vessel and kind of vacuumed the spume off and drew it under the vats. I would think this accompanied the development of metal vats.

Cleansing meant transferring the beer to casks that were tilted so the yeast could rise and lift off through the bung hole, and the Unions were a variation on that.

Possibly here the slates beer was cleansed when the gravity and temperature were taken, but the skimmed beer would I believe have been skimmed in the old paddle way, a relatively inefficient way although it is possible the term was used to describe the chutes too (since only the two options appear given, cleansing and chuting so to speak).


Gary Gillman said...

This is good, from Spons, with comments on what the different London breweries did. Of course cleansing had variations: cleansing from barrels, or from squares and rounds, or from a pontoon system, or a cask union - in each such case with the beer transferred from the primary fermenter.

The other ways were skimming with an oar into spouts or funnels built at the edges of the vats, where the beer clarified completely in the one vessel, and finally the use of parachutes to suck the spume from the top of beer in the primary vat. At least that is how I understand it. It is hard to be sure BP were doing exactly in the period discussed from terse expressions in logs like cleansed or skimmed. Still, I would have thought skimmed meant the beer was cleaned of yeast with a wooden or other paddle, and cleansed meant probably in the slate squares. Possibly skimming was used for the metal and wooden vats. Perhaps the slate squares were used to cleanse beer (i.e., finish it) initially fermented in such metal or wood.


Ron Pattinson said...

Gary, Barnard says their squares were fitted with parachutes. That was in the 1890's.

Gary Gillman said...

There were two types of squares: cleansing squares, into which the beer was transferred after a rough skimming and in which it completed fermenting and was cleansed; and fermenting squares proper. I believe Barnard was referring to the latter kind for BP.


Graham Wheeler said...

You will need to learn an awful lot more about the layout of the B.P. brewery if you are going to come to any useful conclusions, judging by the almost indecipherable nature of the logs, particularly in snippet form, and the fact that B.P. always seem to be about fifty years behind the state of the art for the day. It would be useful to discover why the brewer felt a need to distinguish between wood and copper. Is there some technical significance to it, is it just an odd assortment of vessels, or is it some arcane brewing superstition. Presumably copper is copper-lined wood, or copper-lined cast iron. Knowing if these different types of vessel are on different floors, and which type commands which other type would give a clue.

Why is there a need to distinguish between skimming and cleansing? Skimming is still a cleansing process. It is recorded that in 1879 B.P had 'rounds', 'squares' and Pontoons. Did those pontoons still exist in 1920? My feeling is that they did. Perhaps "cleansing" was the stuff that went into the pontoons.

SB usually stands for "Settling-Back", which is usually a vessel used post fermentation for... erm... settling the yeast before racking. Sometimes it is the same vessel as the racking-back, but often it is a different vessel to save tying up a racking line for a day. However, in this case it seems to refer to something different, but they are certainly the 'slates'. They could be fermenting in them, but that might not be true. There does appear to be some dropping going on. Things change in the last three rows in the 'State Of The Tuns' table and it seems that a transfer has taken place at that point. It is the point where the squares or slates are first defined and the units in the sacc column appears, inexplicably, to change from S.G to pounds per barrel (except in the first snippet). You can see from snippet number two that the beer remains in those vessels for at least a whole day after the time in the last three rows, and that it is being progressively cooled to encourage the settling of any yeast in suspension.

Why is there a 'State Of The Tuns' table when the abbreviation 'F.Vs.' clearly shows in another table. Implies that the table was originally meant for their maturation vats and that fermentation was recorded elsewhere.

In the photos of the brewery you can see the gaps in the duck-boards surrounding the fermentation vessel where the surplus yeast escapes into another vessel, chute, or trough. That probably counts as 'skimming' even though it is a sort of automatic operation. There does not seem to be a parachute on that one.

In the cooling loft, why is the bloke peeing into the cooler?

It seems to have been a red-letter day for steam-powered compressed air. What were they using before - horses?

'Crate' is a new one to me. Seems to refer to bulk beer shipped off to other breweries for bottling locally, Buckley's being the only one clearly visible. I suppose the etymology of crate must be something to do with transport and not a box. Perhaps it referred to open crates, that is a wooden frame surrounding a hogshead or something for stability and ease of handling.

Ron Pattinson said...

Graham, crate means bottled beer in quart screwtop bottles sold in a crate of four. I've seen old adverts for this type of packaging.

I can't say I can see any evidence of dropping. In Fuller's and Truman logs it specifically says "dropped". And, in the last example, there are references to "liquor". It's referring to the attemperators being switched on. I'm pretty sure that in a dropping system only the settling square has an attemperator.

I think you're right that SB stands for "settling back". I assume this is a different type of fermenter from. Though the name implies that it has been moved there from anotgher fermenter.

Under the heading "State of the Tuns" it's always the primary fermentation that's recorded. It's a feature of Barclay Perkins logs stretching way back.

Barnard doesn't mention Barclay Perkins having pontos, but the description of the fermentation room isn't very extensive. Some fermenters he just calls "rounds" without a detailed explanation.

It's interesting how the attenuation varied in the different types of fermenter.

Gary Gillman said...

I find this compressed discussion and the diagram helpful to understand mechanical arrangements that can be combined in more ways than I thought. I agree of course skimming is a mode of cleansing (perhaps the original way). But I think it is used in the above and some other discussions, and at BP in this period, to refer in essence to a completed fermentation in one vessel. In my view this is what occurred in both the wooden and copper (or copper-lined) vessels. How the skimming was done I am not sure, perhaps parachutes were used similar to what is shown in the diagram referenced, or maybe a combination (a paddle to move the yeast into the stem-like opening as is shown in the diagram). In some cases thought the process as Graham states seems to have been automatic as he points out for the gap-lipped fermenter pictured which appears to be metal or metal-lined.

In contrast, some breweries did dropping in the narrow and broader senses of a ferment transferred to a second vessel (or series of them) for completion of fermentation and cleansing.

I think the slates was probably a primary fermenter that wasn't cleansed when tested.

Just from what I see here, I don't think there was dropping (no pontos at this period, no unions) unless the slates was a secondary fermenter of some kind, but I don't think it was.

I don't understand though why the testing wasn't done at the same hour for each, which is why I thought initially the notes might have been referring, at least in part, to the same liquid progressively transferred.


Graham Wheeler said...


It is pretty boring if 'crates' just mean bottles. I thought that I had acquired a new brewing term. Surely all bottles come in crates. Trade, bottling and crates are treated differently in the log from the beginning. I was rather hoping that 'crate' was just a pseudonym for contract brewing, particularly as crates seem to go off to other breweries. What was 'bottling' then. The gravities are far too low for 'bottling' to go out in casks for publican bottling. They'd never get away with it. Ah well.

Almost certainly all the F.Vs. would have had attemperators, apart from the collection vessels if they had separate collection vessels. They would never hold the temperature down without them. They did ferment hot anyway. 73F is bloody hot.

Perhaps I am using the term 'drop' too loosely. What I should have said is transfers. There had to be two transfers in at least one instance, and that is the SBs.

By a process of elimination:

1). The SBs have to be the 'slates' because they are all that are left.

2). Only the SBs are 'cleansed', the rest are skimmed.

3). Cleansing by the traditional definition has to be performed in an enclosed vessel such that the rising CO2 purges the yeast out of the beer and pushes it out of the cask, union, or pontoon.

4). Pontoons are most likely because it seems that they already had plenty in 1879.

5). So the beer was fermented somewhere, moved to the pontoons for 'cleansing', then moved to the slates for settling or racking.

6). Without the above, the term 'cleanse' doesn't mean much.

They might have been phasing out their pontoons, but in the last snippet published, half the 'fermenters' were still slates. They were certainly phasing out wood, presumably by lining their wooden vessels with copper. I dare say that the low gravity beers of the war and their high fermentation temperatures were giving them infection problems in good old porous wood.

Their pontoons (and rounds and squares) are mentioned here:
Which you are doubtless aware of. The author is not a brewer, so it could be expected that he would get some stuff wrong, but he would not have known what pontoons were unless he pointed to one and asked someone what they were called. Nevertheless, lack of knowledge or not, his description of the mash tun and copper was informative.

Several months ago, in your posting about B.P. water treatment in 1936 I said:
Treated Cold? So cold water in the hot liquor back (wrong place for it), add the gypsum cold and then pump it to the liquor copper, probably on the floor above, to boil it. Not on your nellie matey!... ....I am sure that Barclays would have had more than one copper and would have had dedicated liquor coppers - the jiggling of resources would not be necessary in a big brewery.

It turns out I was wrong. According to the above link, in 1879 they did exactly that. The had five independent brewing set-ups and each one had just one copper that served to heat the mash liquor and do the wort boil. The copper was on the floor above the mash tun, rather than below it as is normal. The copper heated the mash liquor and after the mash the sweet wort was pumped back upstairs to the same copper to be boiled. How inefficient can you get? This means that they cannot start to heat the mash liquor for the following brew until the wort boil is over - several hours between sessions. With just a couple of dedicated liquor coppers shared between the five set-ups they could have doubled or tripled their output and vessel utilisation. The fact that this situation seems to have still been extant in 1936 is gob-smacking. Ho hum!

Gary Gillman said...,+perkins&lr=&as_drrb_is=b&as_minm_is=1&as_miny_is=1800&as_maxm_is=2&as_maxy_is=1920&as_brr=0&cd=1#v=onepage&q=slate%20squares%20barclay%2C%20perkins&f=false

Well. I think the above brief but perceptive survey of British breweries from an interesting source - a travelling American revenue commission - assists to clarify some things and supports essentially Graham's last interpretation.

The Commission found that BP (this is mid-1800's) was using pontoons for cleansing but only for ale. For porter, it used, as Guinness did, settling backs - clearly the same "SB" as Graham said were such vessels in 1902.

By 1902 or some time after however, pontoons were out. Fermentation either was completed in one go in the wood and metal FVs, or, it was started in one of these and finished in a slate settling back. Perhaps porter was still treated in the latter way although the other snippets refer to XLK (ale) as made by any of these means.

Also, note the Commission's finding that no slate was used by Guinness or BP, only Truman was doing so. Truman was probably an innovator in this regard but later BP followed suit.

But the point being (or as I interpret it), the slates was in fact a vessel to finish transferred beer; the other FV's were not.


Graham Wheeler said...

After reading some of my own references, looking round the Interweb, and analysing those log fragments more critically, it is now clear to me that some sort of 'drop' or vessel transfer took place immediately before the last three rows in all four log snippets. At that point the fermenting beer was dropped either into slates or into pontoons. I have to agree with Gary that the pontoons were most likely gone by 1919. However, whether or not they were gone, they were most unlikely to have used both slates and pontoons in the same brewing, contrary to what I said in my earlier post.

Because 'dropping' is general-purpose brewerspeak for transferring the contents of one vessel to another by gravity, it is common for writers to confuse the term with the double-dropping cleansing system. In the Barclay Perkins case given here, it is not the same thing. They are dropping too late for that; they are in fact 'cleansing'. They are transferring towards the end of fermentation, at the same point that they would have done a hundred years earlier into trade casks or pontoons.

The first drop of the double-dropping system is earlier, after the lag phase of the yeast is over, usually twelve to sixteen hours after pitching. This rids the wort of the cold break, bits of grain carried over from the mash, and the muck carried up by the first dirty yeast head. B.P do not seem to have been too bothered about that, although the logs do not specifically mention any transfer operation, even the one that has now obviously (to me) taken place.

It is clear from Barnard that the majority, if not all, of the London porter brewers used pontoons in his day. Even though pontoons were not specifically mentioned by Barnard as being present at B.P., it is clear from 'Old and New London' by Edward Walford (the link that I pointed to earlier) that they were in use at least as late as 1871. As Gary mentioned, his linked reference (the American revenue one) states 'settling backs' by name as being present at B.P. in 1865. It claims that settling backs were used for porter and pontoons for ales, but that is certainly the wrong way round. Pontoons would have been used for porter, as traditionally was always the case, and SB's for ale because they were trying to copy what the successful ale brewers were doing. The fact that porters and ales were treated differently is no surprise, but it seems that pontoons and settling backs were operated in parallel for a good number of years, probably for as long as they had been brewing ales, although I suppose that mild could be classed as an ale. The question is how long did this go on for. At what point did their pontoons become redundant. As porters gradually became running beers, with little or no maturation or staling, there was little reason to treat them any differently to ales.

Graham Wheeler said...

Nevertheless, in the first snippet, of 1899, there is a blank line to delineate the point at which the beer is transferred. There is a gap of 17 hours and a big gravity drop between the measurements above and below the blank line. Then there is a gap of two days while it cools and settles. It is not clear whether they racked from that vessel or if they transferred to a separate racking back. Because this is probably a porter, and because they do not find it necessary to specify what it was transferred to, it could, if they still existed, have been moved to pontoons at the blank line.

In the second snippet, just seven years later, they change to lbs/brl to delineate the drop and they find it necessary to specify what type of vessel it went into. This will not be pontoons. We know from the top of the page that it went into slate settling backs, wood skimming backs and copper skimming backs. There is a gap of a day before any measurements are taken and the gravity has dropped 9 points to 1013. According to the top of the page there is another day before the beers are racked or transferred to a racking vessel in the racking room.

The last two snippets are proof conclusive that there was a transfer involved. Similar observations as to timings and gravities can be made, but in the penultimate snippet, FV16 and FV17 are moved to copper skimming backs, whereas in the last snippet FV16 and FV17 are sent to settling backs and are 'cleansed'.

What has to remain a mystery is why they found it necessary to specify the material these vessels were made of. Technically a skimming back would be narrow and tall so that there is a thicker, easier to skim, head, and a settling back would be broad and shallow so that the yeast in suspension has less distance to fall. There is no reason why brewers could not skim a settling back, they invariably did, and likewise no reason why settling cannot take place in a skimming back. Indeed, as B.P had settling backs at least fifty years before that date, it is unlikely that that there was ha'p'orth of difference between any of the vessels apart from the materials they were made of and the terminology. There is a remote possibility that the slates were fully enclosed vessels in imitation of a pontoon or a Yorkshire square. The upper chamber of a Yorkshire square disappeared fairly early on, although the sealable manhole stayed, and slate was a common material for them to be made of after the upper chamber went. This would fall in better with the term 'cleanse' that B.P. were using for their slates.

According to an article on Zythophile's blog, Whitbread were using Pontoons in 1889, just ten years earlier than the first B.P. snippet here, but were dropping into 'slate tanks' as late as 1955. As all brewers in a particular region tended to copy one another, it is fair to assume that what was going on at one brewery was echoed at the others sooner or later. This probably rules out imitation pontoons. However, Whitbread do seem to have been dropping early, as in the true dropping system, whereas B.P were dropping late.

It will have to remain a mystery.

Gary Gillman said...

Okay, so if I understand it now, all the beers were dropped in the sense of being transferred from an almost complete primary fermentation stage to backs or tanks (wood, copper-lined or slate) to finish and become clear. This would seem to exclude pontoons which consisted of numerous vat-shaped vessels through which a trough ran to collect yeast.

The only reason I thought the mid-1800's account by the revenue commission made sense (i.e., that pontos were used for ale, settling backs for porter) was that pontos seem, and I have read they are, a kind of unions system except not linked as closely in the same way. And Burton developed unions to perfect its pale ale. So if London was copying Burton (by then) for best practice, would it not have reserved pontos for ale? I note too the account stated not just that BP used settling backs for porter but Guinness did too which suggests an antiquity to the practice for porter-brewing.


Gary Gillman said...

Another reason settling backs makes sense to me for porter is that porter as we know was stored, or some of it was. Ale generally was not. In a settling back, no matter how shallow it was, surely it took time for the yeast to precipitate - perhaps these were used as a form both of clarification and aging in other words. I know it can take yonks for some unfiltered bottled beer I buy to clarify.

Whereas those little pontos - actually I think the pontos technically were the frame the vats sat on - would disgorge their yeast fast. You couldn't store beer in those for very long. Indeed that was the point of using them, a smaller volume of beer would clarify faster and better. One of the authorities I cited, Spons I read, stated that.

Now, once all beer including porter was running gyle, it wouldn't have mattered which you used, apart from the usual throughput/efficiency factors of course, since the beer wasn't kept in them long. It makes sense to me that the pontos would go first because even if they worked fast to disgorge yeast, you needed to take the trouble and time to fill and empty a whole bunch of them.

By extension, the same logic applies to the Unions. It makes sense (I see now) that Bass got rid of them. Why were some people so upset, then? If they knew about Ron's work and all the thinking it stimulates, they wouldn't be upset at all! Right?


P.S. Oops, I forgot about palate. But so often these historical excursions have convinced me it was, even to the Southby's, Booths, etc., rather down the line of what needed foremost to be considered. And you can't blame them, they were in a competitive business with constant threats from this side and that.