It's the same style, but from a later period. Well, the next period, really. As this is for 1921 to 1929. Didn't the last period end at 1914? Why is there a gap? Because WW I totally messed UK beer about. In the latter stages of the war, changing restrictions meant styles were sometimes changing every couple of months. T cover the whole war I'd need at least half a dozen different definitions. If you're interested in seeing what they might look like, get yourself a copy of Armistice!, my book about brewing in WW I.
Unsurprisingly, the gravity is lower than before WW I. Though the strongest examples were about the same OG as the weakest pre-war versions. The gravity is no accident. These beers cost 8d per pint in the public bar. In the last set of wartime price controls, the top slot, costing 8d per pint, was set at anything over 1055º. And even after the controls were abolished, 1055º remained the highest gravity pretty much any draught beer was brewed to. In London that meant Burton Ale, Stout and PA.
The only changes to the grist are that no London PA was brewed from 100% pale malt and that a few examples employed a little crystal malt. But that was definitely the exception rather than the rule. Most PAs still only contained pale malt.
As for the hops, pretty much anything goes. Ones from Alsace, Belgium, New Zealand, Canada and everywhere else that grew them are possible. I've not mentioned some of the older varieties such as Cobb, Tolhurst and Colgate as they aren't currently available and, as they were of lesser quality, they weren't usually found in strong Pale Ales.
The preferred varieties, especially for late copper additions and dry hopping, remained Goldings, Fuggles and sometimes Saaz or Hallertau. Cluster, whose aroma British brewers weren't great fans of, was limited to early copper additions.
|Interwar London PA (Best Bitter)|
|SRM||6 - 10|
|flaked rice or maize||10-15%|