I've already mentioned some of the following in a comment to an earlier post. But I'm worried I'll forget where it is, so I'm converting it to a post of its own. If you see what I mean. Must have left my writing head at home today
Here are the vital statistics of Fuller's X, AK and PA:
You'll note that the hopping rate of the AK (in terms of pounds of hops per quarter of malt) is exactly halfway between the hopping rate of the PA and X.
Barclay Perkins are a good choice for comparing K and X Ales. As you'll see in the table below, the corresponding X and K Ales had the same OG, but the K's were more heavily-hopped.
Last time at the London Metrolpolitan archives I photographed some Ale logs that also demonstrated the relationship between X and K Ales. I think they were Truman's logs. The beers were called X, XX, XXX and KXX, KXXX, KXXXX. You see the same K prefix used with, for example, Porter. It always means a Keeping version. Truman's Porter's were always prefixed by either Runner or Keeping. You had things like Country Runner, Keeping Double Stout, etc.
I must try to get through the relevant logs. I'm sure they will broaden our knowledge.
Bamford Beer Festival -
11 hours ago