As promised, far more details than you could possibly want, courtesy of the Whitbread and Truman Gravity Books and the Whitbread brewing logs. I'm sure you wanted to know how strong SS was in 1844.
Below are the gravities of the Whitbread Porter and the main Whitbread Stouts. Like all the big London Porter breweries, they produced several Stouts. Pre-WW I, it was fairly simple - S (Single Stout), SS (Double Stout) and SSS (Triple Stout). During the war, only Porter and a new strong Stout, Imp (Imperial, I guess) were brewed. Postwar, there were Porter, draught LS (London Stout), bottled LS and bottled ES (Extra Stout).
In case you're wondering, none of these were Sweet Stouts. All had 65-70% apparent attenuation. Not as attenuated as Guinness (that was 70-75% at this time), but by no means sickly sweet. No Sweet Stout was produced at Whitbread's Chiswell Street brewery in London until after Mackeson was taken over. Mackeson Milk Stout seems to have been brewed at most Whitbread breweries during the 1950's.
See how handy my Mega-Gravity Book is? How much more useful it would be with a few more recent decades included.
I keep including vaguely-hidden plugs for my two beers, SSS and Porter. Here's another. (I'm not quite sure why I bother, given the tiny amounts of each. I could drink the lot, if need be. That would be pretty cool, drinking most of it myself. Mmmm. 100 more boxes of SSS. Nearly 6 months supply.) You can see them in the table. Now you can see how they fit into Whitbread's range in terms of strength and time. It was the end of the road for SSS after nearly 100 years.
British beer has been particularly affected by history. The Napoleonic Wars spurred technoligical advances. The two World Wars decimated gravities. Little proper beer was brewed in Germany in the 1940's. But in the 1950's, as soon as they were able, they went back to pretty much the pre-war gravities. Why is that?
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