If you can recall that far back, we’d conditioned our beer in a warm tank before transferring it to a cold tank. The big question is: how long should it stay there?
“Exactly how long beer should remain in a cold room depends upon various circumstances, and is also a matter of opinion. With a heavy rush of orders during the summer it may be possible to give it a few hours only. If a tendency to fob when being bottled, as well as a risk of the filters choking rapidly, is left out of the question, experience has shown that it is possible to obtain quite good results by such a short period of storage. Others, however, maintain that the beer is unmistakably better if kept in the cold room for a fortnight or three weeks. It is claimed that this long period of storage obviates fobbing. We are not in a position to express a definite opinion on this subject, but we do think that the beer should be given a week at least in which to settle down after being transferred from the conditioning tank and being chilled. We do not consider that this procedure would prevent fobbing, because it is our belief that this trouble is due to other causes, as discussed later in this chapter. It must be quite obvious that if the beer is given time to rest a considerable deposit of sediment must take place in the tank. This deposition greatly relieves the filters of the risk of premature choking.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 340.
This is starting to sound more and more like lagering. OK, in the 1950’s central European breweries were probably lagering Pilsner for at least 8 weeks. But their beers were stronger than most British bottled stuff so would have need longer. Working on the old one week lagering per degree Plato, a British Brown Ale of 1032º (8º Plato) would need 8 weeks. But that’s the 19th-century standard. After WW II you could probably halve that. Meaning a British Brown Ale could have been receiving a similar conditioning to a Lager of the same strength. Weird.
I think I can understand why. Non-deposit bottling was imported into Britain from the US, where Lager-brewing techniques had greatly influenced even Ale breweries. They had a roughly similar process for bottling both Ales and Lagers. British brewers copied the Americans and unwittingly ended up using some techniques similar to Lager brewers.
I can’t imagine for a second anyone goes to all this trouble now in the UK. It’s a long process. Remember that the beer had 2 weeks in the warm tank. Another 2 or 3 in the cold tank and it’s starting to add up. You’re looking at 6 weeks from mashing to bottling.
Why don’t I just check? I’ve got a shiny new brewing text book.
"Now many types of ale are brewery conditioned and filtered and sold in kegs (Chapter 23). Ale fermentations are rapid and vigorous and usually completed in 48 to 60 hours (Chapter 12) at temperatures of up to 24ºC (75ºF) before being cooled to < 10 ºC (50ºF) as rapidly as possible to encourage yeast separation. A period of warm conditioning for a brewery conditioned beer can take place in the fermenting vessel at around 15ºC (59ºF) before cooling and transfer to the maturation vessel. Diacetyl reduction is not a problem and low levels of diacetyl (0.1 mg/l) are a constituent of some ale flavours. Brewery conditioning of ales focuses on cold treatment to `fix' the flavour of primary fermentation and to ensure the elimination of haze precursors. Yeast is removed by skimming from the top of the fermenter at the end of primary fermentation and the beer is conditioned at -1ºC (30ºF) for 48 to 120 hours."
"Brewing Science and Practice" by Dennis E. Briggs, Chris A. Boulton, Peter A. Brookes and Roger Stevens, 2000, page 548.
That indeed sounds much shorter. And with fewer vessels. A short warm conditioning in the fermenting vessel then a couple of days in the cold tank. Sounds like no more than around a week conditioning.
Should you bottle straight from the filter? Not according to Jeffery:
“Many bottlers fill direct from the filters, but we are not in favour of this method. It is difficult to synchronize the flows of filter and filler, especially as the build-up of deposit on the plates gradually slows down the filtering process. Moreover, we think this procedure may be one of the causes of fobbing. It is preferable to filter the beer into a supplementary tank. The beer should, if possible, be allowed to remain for two days under top pressure in this tank, which must, of course, be situated in the cold room, and bottling should then take place. In this way an even pressure can be maintained until the last drop of beer has been bottled. Although the beer has probably passed already through two filters a further deposit may take place in this additional tank. This fact contributes towards extreme brilliancy of a lasting nature and a lessened tendency towards the formation of haze. In many cases, however, it is necessary, because of lack of tank space, only to leave the beer in it overnight.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, pages 340 - 341.
So ideally you need yet another specialist vessel, a pressure tank in the cold room. It makes sense that bottling would be easier if the pressure were constant. But I can understand why many wouldn’t want to go to the extra expense of yet another tank.