There was quite a lot of variation in rates of attenuation – from 60% to 85% – but most Brown Ales were in the range 65% to 70%. That’s on the low side compared to most draught beers, but is probably a result of the way Brown Ale was brewed. Most were Mild Ale recipes which were primed and then bottled. Unlike in cask Mild, there was no chance for the primings to ferment out before sale as the yeast was removed and the beer stabilised either by chilling or pasteurisation.
Much like London Milds, Brown Ales brewed in the capital tended to be at the darker end of the spectrum, averaging over 90. Around 80 would have been typical for examples brewed in the English provinces.
|London Brown Ale after WW II|
|Date||Year||Beer||Price per pint (d)||OG||FG||ABV||App. Atten-uation||colour|
|1946||Barclay Perkins||Doctor Brown Ale||13.5||1034.1||1011.3||2.95||66.86%||105|
|1947||Barclay Perkins||Doctor Brown Ale||14||1034.2||1007.4||3.48||78.36%||120|
|1947||Hammerton||Nut Brown Ale||12.5||1027.6||1003.9||3.08||85.87%||80|
|1947||Mann Crossman||Brown Ale||14||1035.3||1011.4||3.09||67.71%||82|
|1946||Taylor Walker||Nut Brown Ale||17||1030.1||1007.6||2.92||74.75%||82|
|1947||Taylor Walker||Brown Ale||13||1030.3||1007.3||2.98||75.91%||85|
|Whitbread Gravity book held at the London Metropolitan Archives, document number LMA/4453/D/02/001.|