When did Burton Ale originate?

I don't mean when did the beer first called Burton Ale appear. Rather, when were London-brewed Stock Ales first called Burton Ale? But that was a bit too long for a title.

I started wondering about this when writing a post about a Fullers Stock Ale recipe from 1887. I know that later it would have been called a Burton. But was it back in 1887?

My gut instinct said late 19th century. I know from a London publicans' price fixing agreement from around the start of WW I that Burton Ale was part of the standard draught range of a London pub. Logically, the term must have pre-dated WW I by at least a decade. But how to nail down a more precise date?

Being a very lazy person, the first thing I did was to ask Martyn Cornell. Him being a fount of knowledge on everything connected with brewing in London. Unfortunately, he didn't know any better than me., coming up with around 1900.

Getting off my lazy arse a little, I remembered my spreadsheet derived from brewery price lists. Bound to be something in there. Sure enough, there was. This from 1893:

Kelly's Directory for Ealing, Acton, 1893-94

It ticks all the boxes. A London-brewed Strong Ale clearly named Burton. I've knocked the date back to the early 1890s. Surely it must be older than that. I'm guessing at least the 1880s.

Why don't I just check all the London brewing records I have? Because brewers called beers differently in the brewhouse. What a drinker called Burton, was KK or KKK internally. At least at the big breweries. 

The same was true at smaller Fullers. Where in the 1880s and 1890s, their Burton was called XXK inside the brewery. Though sometime between 1898 and 1902 the name was changed to BO - Burton Old.

My curiosity now roused, I've started trawling the newspaper archives. Beginning with the 1860s, where I came up with zilch. I'm now on the 1870s. I'll let you know how I get on.