The tank conditioning process was quite complex. As the following demonstrates:
“In the following table is given an illustration of the conditioning of a beer of medium gravity (19 lb. = 1053). In some cases a longer period might be given in the conditioning tank.
Description Special Pale Ale (Gyle 11) Present gravity 3.5 lb. (1010) Tank No. 2 Date when filled 2nd May. Hops in tank 4 oz./barrel — 15 lb. Priming, etc., in tank 1 quart per barrel = 15 gallons.
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 336.
Date. Time. Temp. of room. Pressure of tank. Temp. of tank. Hours of rousing. Remarks. May 2nd m 6 60°F. - 59.75° F. - Filled. e 6 61 1 60.5 - - „ 3rd m 6 61 2 60.5 - Blown off to 1.0 lb. e 6 61.5 4 60.75 4 - „ 4th m 5 62 7 61 3 - e 6 62 9.5 61.5 4 - May 5th m 6 61.5 11.5 61.5 3 - e 6 62 12.5 61.75 4.5 - „ 6th m 5 62 14.5 61.75 4 - e 6 62.25 16 62 4 - „ 7th m 5 63 17.5 62.5 3 Warm night. e 6 62.5 18.5 62.5 4 - „ 8th m 6 62.25 20 62.5 4 - e 6 62.5 21 62.5 5 - „ 9th m 5 62.75 22 62.75 3 Blown off to 17.0 lb. e 6 62 18.5 62.5 4 Cooler. „ 10th m 6 62.25 20 62.75 4 - e 6 62 21 62.75 3 - „ 11th m 6 62.5 22.5 63 4 Blown off to 20.0 lb. e 5 62.75 21 63 2 - „ 12th m 6 63 21.5 63 4 - e 5.30 62.75 22 63 4 - „ 13th m 6 63 22.5 63 2 Blown off to 21.0 lb. e5 62.75 21.5 63 - - „ 14th m 6 62 22 63 - Cold night. e6 62.5 22.5 63 - - „ 15th m 5 62.75 22.5 63 - - e6 63 22.5 63 - - „ 16th m 6 63 22.5 63 - - „ 17th m 6 63 22.5 63 - Blown over to cold stores. Final gravity 2.0 lb. (1005.5) Bottled 27th May.
I’m surprised that the beer was so long in the tank – more than two weeks. My guess is that at some point they cut out the conditioning and just filtered and artificially carbonated right at the end of primary fermentation.
You can see how during its first 10 days in the tank the beer was roused to encourage conditioning, but care was taken not to let the pressure in the tank get too high, with some CO2 being let off every so often. You can also see how the beer warmed a little in the tank, eventually rising to the temperature of the room, 63º F.
This is the process for a stronger beer:
“For a strong ale (27 lb. = 1075) a period of 30 to 35 days would be given and the pressure would be allowed to reach perhaps 28 lb. With the stronger beer a somewhat lower temperature of the conditioning room might be advisable to prevent pressure rising too quickly, say from 60 to 61.5. During this period the gravity might drop from 5.5 lb. (1015) to 3.5 lb. (1010). The hop rate might be half a pound per barrel; priming half to one pint per barrel. For a light ale of gravity about 12.5 lb. (= 1035) from 10-14 days would normally be given, although some brewers give periods in excess of this even for the light gravity beers. The hop rate would be probably 2-3 oz. per barrel. Priming one to two pints per barrel. Pressures might not reach those given in the table.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 336.
At a month or more, that’s starting to look like lagering. Except for the much higher temperature. I’d have expected a beer of 1075º to have more dry hops than two or three ounces. In 1946, Barclay Perkins added four ounces to their KK, which only had an OG of 1043º*. Though that was a draught rather than a bottled beer.
Talking of Barclay’s KK, that was primed at a rate of four pints per barrel. While XX, their Mild, had six pints per barrel**.
Mild sometimes received special treatment:
“As soon as it is considered that sufficient maturation time has been given the beer is blown from the tank through a chiller to the cold storage tanks. In some breweries where a sweet mild ale is desired priming is added at this stage instead of, or in addition to, that added in the conditioning tanks and is injected into the beer as it passes through the chiller. A sweet luscious priming will be used for this purpose. Up to a total of four quarts per barrel is sometimes used. For mild ale of this kind it is desirable to pasteurize, as the large amount of sugar would give vigorous growth of any trace of infecting organisms. Nevertheless, if a quick trade is expected sterile filtration and care in bottling is often sufficient.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, pages 336 - 337.
That was probably how most breweries produced their Brown Ale: by sweetening and bottling their Mild.
The perils of oxidation next.
* Barclay Perkins brewing record held at the London Metropolitan Archives, document number ACC/2305/01/627.
** Barclay Perkins brewing record held at the London Metropolitan Archives, document number ACC/2305/01/627.
So if I'm understanding this, they used some kind of regular sugar for sweetening milds and browns. Any idea why they wouldn't use lactose like other times it went into stouts? Something to do with adding too much body maybe?
ReplyDelete1.053 down to 1.005 - will English yeasts always attenuate so highly, if given enough time/rousing? (My interest is as a home brewer trying to get to grips with bottle conditioning in a cellar that gets up to 20c in the summer! I was waiting for this post, great that the gravities are stated)
ReplyDeleteTom Challenger,
ReplyDelete1005.5 is pretty low, but not unknown. I doubt cask beers would ever get so low. This is an example of a low FG:
1955 Bass Blue Triangle OG: 1063.5 FG: 1003.1
Anonymous,
ReplyDeletethey had all sorts of specialist sugars for specific purposes. They were after flavour profile and colour. Pure lactose didn't fulfill those needs.
I for one was disappointed when you moved on from conditioning tanks to reviewing random Dutch beers I'll never have the occasion to drink. Any more info on how to build a conditioning tank with a propeller would be welcome. They are fun.
ReplyDelete