I have multiple breweries' AKs from WW I and could turn out a nice big table. Except that it would be confusing, as gravities might change two or three times in a year. To show the changes to AK over the course of the war it makes more sense to concentrate on a single example. Having a shitload of their records, I've plumped for Fullers.
Surprisingly few changes occurred in the first half of the war, with the gravity on;y falling a couple of degrees. The fun started in the spring of 1917 when the German unrestricted U-boat campaign started to seriously threaten the UK's good supply. By spring the following year, the gravity had been reduced to a pathetic 1026º and a mere 2.73 ABV.
I got quite a shock when I assembled the table.Contrary to what you'd expect, the hopping rate per quarter (336 lbs) of malt increased during the war. This is the figure that takes the beer's gravity out of the equation. The rate per barrel was barely lower in 1920 than it had been in 1914, despite the OG being almost a third lower.
Speaking of that reduction in OG, let's see how it compares to the average for all beer brewed in the UK:
|UK average OG 1914 - 1920|
|Brewers' Journal 1921, page 246.|
Fullers AK fared worse than the average. In general, beers that started with a modest gravity seem to have been worst hit by the reduction in gravities. Porter, Mild Ale and Light Bitter were all hit hard.
|Fullers AK in WW I|
|Date||Year||OG||FG||ABV||App. Atten-uation||lbs hops/ qtr||hops lb/brl|
|Fullers brewing records held at the brewery|
Next time we'll be looking at the grists.