For a couple of reasons. Most important being that the last Stout data was for two different beers: Single Stout and Export Stout. Which made the bitterness chart look weird. Also because I want to check how closely the grists of the Double Stout and Stout resemble each other.
There's no amber malt, just the same as in Stout after 1816. Most of the big London brewers seem to have eschewed its use. Except for Barclay Perkins, who regularly employed it, especially in their more expensive Stouts.
Biggest difference with Stout is the much more stable brown malt content. Which also leads to the pale malt percentage showing less variation, too. At least until 1870, where some was swapped out for sugar. While the black quantity rose slowly and steadiyl.
First, the data in number form:
|Whitbread Double Stout 1830 - 1880|
|year||OG||IBU||SRM||pale malt||brown malt||black malt||sugar|
|Whitbread brewing records held at the London Metropolitan Archives, document numbers LMA/4453/D/09/024, LMA/4453/D/09/029, LMA/4453/D/09/034, LMA/4453/D/09/040, LMA/4453/D/09/045, LMA/4453/D/09/049, LMA/4453/D/09/053, LMA/4453/D/09/059, LMA/4453/D/09/064, LMA/4453/D/09/070 and LMA/4453/D/09/075.|
And now as a pretty chart:
Next I'll be doing a chart of bitterness and colour.