Guinness’s Park Royal Brewery in 1949 – the brew house (part six)

Back in Guinness’s brewhouse. Looking at their refrigerators in ridiculous detail.

We seem to be jumping about a bit in terms of plant, because now we’re going back to the second phase of wort cooling, using refrigerators. And, no, they weren’t the same as a domestic fridge.

“The wort refrigerators are of the multi-plate type of standard pattern, arranged in six lines on the third floor of the fermenting house, each line consisting of two sections of 36 plates, arranged in passes of nine plates. The plates have a cooling surface of 5.5 sq. ft. each. Each line of two sections has a capacity of 60 barrels per hour, making 360 barrels per hour in all, which allows the worts to be cooled in about 10 hours.”
Journal of the Institute of Brewing Volume 55, Issue 5, 1949, page 283.

Remember that they brewed around 3,000 barrels a day. At 360 barrels an hour, I make that 8 hours to cool all a day’s brews. Which seems like an awfully long time. That must be one of the main reasons it took wort so long to get from the mash tun to fermenter.

“To avoid undue scale on the plates, the wort refrigerators are taken down three times a year and the plates dipped in a 26 per cent. solution of caustic soda, after which they are thoroughly brushed and washed. The cooling water services consist of direct water with a winter temperature of 50° F. and a summer temperature of up to 70° F., and artificially chilled water at 45° F., the latter being used in summer. The seasonal temperature ranges are as under:—

Summer
	Direct Water cooling.	Chilled water cooling.
Wort .. ° F.	175 to 78	78 to 55
Water .. ° F.	130 from 70	65 from 46
Water/Beer Ratio	1.6	1.5

Winter
	Direct Water cooling.
Wort .. ° F.	176 to 66
Water .. ° F.	130 from 60
Water/Beer Ratio	1.5

Journal of the Institute of Brewing Volume 55, Issue 5, 1949, page 284.

I was struggling to understand that at first glance. Now I see what it means. In summer they first used water at its normal temperature, then used chilled water to drop it the last few degrees. Obviously you couldn’t get the wort cooler than the water cooling it. While in winter, when the water was cooler they didn’t bother with chilling.  In both summer and winter, the unchilled water rose in temperature to 130º F.

I’m struck by the difference in the temperature of the wort in winter and summer. It looks like they were pitching at 55º F. in the summer and 66º F. in the winter. That’s really unusual. Breweries usually pitched at the same temperature all year round. Then again, most breweries had fermenting vessels fitted with attemperators and could control the temperature of the fermenting wort. If you remember, Guinness’s didn’t have attemperators. Maybe that’s the reason for the different pitching temperatures.

For beer the Strength of Guinness, 55º F. is a very cool pitching temperature. Then again 66º F. is quite high. At most breweries, I’d expect it to be pitch at around 66º F. and hit a maximum of 68º F. to 70º F.

Confirmation that these were the pitching temperatures:

“From the wort refrigerators the wort runs down from the yeast troughs already referred to, to the fermenting tuns arranged on the floor below.”
Journal of the Institute of Brewing Volume 55, Issue 5, 1949, page 284.

The yeast troughs, you may recall, were where the wort was mixed with yeast before going into the fermenters.

Next we’ll be taking a close look at the fermenters themselves. 

Guinness’s Park Royal Brewery in 1949 – the brew house (part four)

Don’t worry. Our slow crawl through the brew house will soon be over. Of course, that’s far from the end of our visit to Park Royal.

Nearly as important as the coppers themselves were the hop back, where the hops ended up after boiling.

“There are two hop backs each of 800 barrels capacity of more or less orthodox design in that they are circular vessels of about 26 ft. 6 in. in diameter and 9 ft. deep, constructed in copper bearing steel to resist corrosion and the usual gun-metal false bottom plates, the slots being 19 s.w.g. i.e. 0.040 in. The hop backs have copper domes with a chimney taken up through the roof for disposing of the vapour to outside the brew house. Disposal of the hop-back vapour in this way appreciably reduces the maintenance of the building steel work, etc. Perhaps an interesting feature is that the hop backs are fitted with revolving rakes for putting out the spent hops. A small dip of weak worts is put into the vessel, the rakes revolved to mix thoroughly the content, and then the hop outlet is opened to a centrifugal "free flow" pump which pumps the spent hops over to the by-products department for draining and drying. The same pumping system is used for returning hops to copper for alternate boilings. The hopped wort from the hop backs is pumped up to the wort coolers which are large open vessels about 26 ft. X 24 ft. and 6 ft. deep, constructed in copper bearing mild steel and located on the top floor of the brewhouse. They are open to the atmosphere.”
Journal of the Institute of Brewing Volume 55, Issue 5, 1949, pages 282 - 283.

Some revealing stuff there. For a start, they hop sparged. That’s what the bit about “a small dip of weak worts”. That means they were adding a low-gravity wort to extract the wort retained by the hops. This was presumably higher gravity than the wort used to flush it out. More surprising was the fact that they returned hops to the copper, i.e. they were reusing spent hops. Very odd at this late date.

Note that they were still using open coolers, despite having refrigerators for cooling wort. Coolers (not fucking coolships) remained in use because, in addition to cooling wort, they were useful in removing all sorts of gunk from the wort. Being very shallow, sediment dropped out more quickly. As was usual, they were located at the top of the brewery, where the flow of air was best.

Not that coolers cooled the wort that, er, cool:

“The wort lies here where atmospheric cooling is allowed to lower the temperature to 176° F., which ensures that the temperature, when running down, does not fall below a safe figure. The wort is discharged into the wort coolers over aeration hoods.”
Journal of the Institute of Brewing Volume 55, Issue 5, 1949, page 283.

Aeration hoods? Surely you wouldn’t want to aerate the wort at this point? Would you? I guess by wort coolers they mean refrigerators, whose form and function I described earlier.

Not sure what’s next. Something.

Brewing in the 1950’s – coolers

Back with coolers again time for more ranting.

I just want to get one thing off my chest before we start. Coolship is not an English word. It’s a translation of the German or Dutch – Kuhlschiff or koelschip. It’s really irritating when people don’t use the correct English word.

Though by the 1950’s coolers were no longer widely used. In the early 19th century coolers had been the only devices used to cool wort. After the development of refrigerators – a system of pipes through which flowed cold water or brine and over which the wort flowed – these were used in conjunction with coolers rather than replacing them. Partly because coolers still had an important auxiliary role in precipitating out gunk from the wort.

“Wort Receiver. If the brewery is suitably arranged, the wort can pass by gravitation to the wort receiver and thence to the refrigerators. Some brewers consider that the use of a pump between hop-back and refrigerator has an undesirable effect upon the colloidal matter in the wort, dispersing it into smaller particles which may affect the yeast in the fermentation: undeniably, if hop-back filtration is poor, insoluble particles in the wort may get broken up in the pump; but such insoluble matter from the hop-back is objectionable in any case, whether or not its adverse effects are increased if it is in smaller particles. Be that is it may, the amount of such insoluble matter in a wort should be negligible; if it is not, the remedy is to be found in improved hop-back filtration. The present author considers that this objection to pumping is without foundation, and the fact of the matter is that many, if not most, modern breweries pump their wort, either to raise it to a wort receiver on a higher floor, or for the purpose of obtaining sufficient pressure for use with an enclosed refrigerator to get an adequate throughput. “
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 47.

It sounds here as if the hop-back had replaced the cooler in the function of removing crap from the wort.

Here’s a little more about coolers:

“At one time the wort would have been discharged into a large shallow cooler. The latter was undeniably necessary before the advent of refrigerators. Exposure of the wort to the air, in a shallow vessel, was the only means of cooling in those days. But during that time the wort could pick up innumerable bacteria and wild yeast, a most undesirable feature. The extensive exposed surface of wort was open to infection from any local sources which might exist. In many cases where receivers were substituted for coolers there was an immediate improvement in the quality of the beer. Open coolers are now hardly ever used in top fermentation breweries. A few breweries however still use them, on the grounds that they provide conditions of cooling and an opportunity for sedimentation that are beneficial to the wort. Lager breweries still use them extensively and they are usually housed in enclosed rooms supplied with sterile air.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, pages 47 - 48.

That’s interesting about Lager breweries still retaining coolers. I guess if they were placed in a closed room, much of the risk of infection with wild yeast was removed. Though the operational coolers I’ve seen in Germany weren’t housed this way. They were just parked next to the copper. Unlike the open fermenters, which were in sealed, refrigerated rooms.

“A receiver is only an intermediate vessel between the hop-back and the refrigerator, and it does not act as a cooler, since it is usually a fairly deep vessel. It must be of sufficient capacity to ensure a regular flow and delivery of wort to the refrigerator. If a spreader in the shape of a dished circular metal plate is fixed at the mouth of the inlet pipe, a certain amount of hot aeration may be effected at this point. Alternatively, the same result may be obtained by discharging at the delivery end into a trough of perforated copper which splits up the wort. This hot aeration is most beneficial towards the subsequent fermentation. Adequate aeration can however usually be effected at the hot end of the refrigerators.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 48.

Hot-side aeration - isn’t that one of the things home brewers go on about endlessly? About how bad it is. While professional brewers have spoken to say that’s bollocks. I see Jefferey is firmly in the pro hot-side aeration camp.

Not sure what will come next. Maybe fermenters.

Brewing in the 1950’s – how to lay out your brewery (part two)

We’re looking at the cooling end of the brewing operation this time. It’s so exciting. I can barely stop myself from weeing my pants.

Remember that we’d got as far as wort receiver. This is what came below that:

“Directly below, again, will be the refrigerators. In an up-to-date brewery, these will almost certainly be of the totally enclosed type. Where refrigerators of the older, open type are used they should be housed in a completely enclosed room supplied with purified air. Means will have to be provided, in these cases, for getting rid of the steam.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 23.

In old-style refrigerators the wort flowed over the top of the cooling pipes, totally exposed to the air. That’s why Jeffery recommends placing them in a sealed room with the air flow controlled. Otherwise there would be a risk of infection.

It seems that back before WW I, brewers relied on high ABV and high hopping to quite a degree. Doubtless they had to tidy up their practices after gravity and hopping rates fell because of the war. I can imagine that the transition was a difficult one.

Here’s an explanation of how cooler and refrigerator worked in tandem to cool the wort to pitching temperature.

“A word of explanation may be added here as to the terms 'cooler' and 'refrigerator' as used in a brewery. The old type of shallow vessel into which the wort was discharged from the hop-back, was called the 'cooler'; in it the wort cooled from the nearly boiling temperature (say 180°-190° F.) at which it left the hop-back, to a moderate temperature, say 120°-140º F. The wort was cooled here simply by loss of heat to the air and to the vessel. The wort then passed to the 'refrigerator' by which it was cooled by water to the required final temperature of 60ºF. This piece of plant, therefore, is not what is popularly understood, as a refrigerator. With the elimination of the open 'cooler' the 'refrigerator' is responsible for the whole cooling operation.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 23.

Remember the word is “cooler” not “coolship”. And that a refrigerator in a brewery isn’t a fridge.
I love the detail with which Jeffery describes the fermenting equipment:

“Finally come the fermenting vessels and racking backs.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 23.

Next time it will be more ranting about coolers.

Brewing in the 1950’s – how to lay out your brewery (part one)

The surprising success of stuff about how to construct a brewery in the 1950’s has prompted me to continue. Ever the populist that I am.

Jeffery gives what looks like very sound advice about the layout of a brewery. Mostly concerned with eliminating possible sources of infection. Something that’s one of a brewer’s greatest fears.

I can’t help thinking of the sad end of Home Ales of Nottingham. I drank their beers a lot when I was younger. They were some of the most reliably sound in the country. I don’t think I can recall a single pint that was in poor condition. The company was well run and profitable. So they decided to build a brand, spanking new brewhouse.

That’s when the trouble started. Because there was a source of infection in the brewery. From that time on, their beer was never right. Try as they might they couldn’t track down the source of the infection. Eventually they gave up and sold up to Scottish & Newcastle. It’s a cautionary tale about the importance of a good brewery design.

“The danger of bacterial infection begins from the time when the wort leaves the copper, since no further sterilization is possible thereafter. It should, however, be comparatively easy to arrange subsequent departments, and the plant through which the beer passes, in such a manner that little pumping is necessary, and the minimum length of piping is involved. The copper, in order to carry out the advised system of gravitation, would be in the highest storey of the building. This arrangement makes it easier, also, to convey away the volumes of steam generated by boiling. Immediately below should be placed the hop-back, which should be an enclosed vessel with a steam chute leading from the top to outside the building. If the steam thrown off at this period is allowed to permeate the department, roof, walls and everything with which it comes into contact will in time become smothered by a sticky, sugary deposit, forming a breeding ground for bacteria and other undesirable organisms at the very place where it is essential to avoid them. Many breweries still have open coppers and hop-backs. Wherever possible these should be fitted with covers and steam vents. Where this is not practicable, special care should be taken to ensure that condensed water does not drop from the ceiling or rafters overhead into the hop-back. However, these expedients do not concerns us at this stage, as we are here considering the best type of plant for a new brewery.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, pages 22 - 23.

The shorter the length of piping, the fewer places an infection can lurk.

That’s something I’d never considered: steam condensing on the roof and falling back into the hop-back. The ceiling isn’t likely to be the cleanest spot in a brewery. Steam sounds like quite dangerous stuff, beyond the obvious scalding risk.

“Immediately below the hop-back should be placed the wort receiver. In a modern brewery this will be a deep vessel. At one time the wort would have been discharged into a cooler—a large, open, shallow vessel - which was thought to be essential at this stage. The open cooler has passed into disfavour as a potential source of infection and is to be found only in a very few breweries.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 23.

Cooler. Remember that word. We’ll be getting to it again later. It’s replacement, the wort receiver, was a different shape and had a different function. It didn’t cool the wort, but merely held it and fed the refrigerator, where all the cooling was done.

We’ll be looking at that in more detail next time.

Brewers' notes

I mentioned about the scribbled notes in the inside cover of brewing logs. Here's your chance to look at some.

These appear in the front of a Barclay Perkins covering 1899 and 1900:


It gives an indication of how recipes were tweaked to cope with changes in the raw materials. For example, you'll see that it notes when the latest season's malt and hops were first used. You can also see how the hopping rate for X was changed several times: increased to 10 lbs per quarter, reduced to 9, reduced to 8, then increased to 9 again.

But my personal favourite is: "our freezing machine broke down". Then three weeks later "men finished & fixed refrigerator". I know. I'm weird.