Session Imperial Stout grists

Bet you thought I’d forgotten about this. And you’d be right. I did forget, distracted by more German top-fermenting stuff.

That’s my biggest problem: I’m interested in too much. I really have try hard to keep my focus, which is British and, to a lesser extent, German beer. If I didn’t, I’d be off all over the place. Believe me, it’s a real struggle.

Back to the beer I’m supposed to be discussing, Barclay Perkins Session Imperial Stout. There are a couple of interesting points about the grist. The use of roast barley is the most obvious. London brewers mostly preferred black malt. And the amount – around 10%.

The versions from the 1920’s have a crazy proportion of dark malts: around 35%. I was so surprised that I went back and checked the brewing records. And it is correct. There’s less than 50% base malt. Though that did decline after WW II started, with the brown malt percentage in particular declining. All those dark malts must have produced quite a thick beer, despite not being massively strong. And a very roasty one.

The amount of flaked maize is quite low. 10-15% was typical of other Barclay Perkins beers of the time. The oats, in this case, aren’t a wartime thing. Look at the tiny quantity. It’s because it was being part-gyled with London Stout, some of which was sold as Oatmeal Stout, requiring a tiny amount of oats for legal purposes.

Barclay Perkins Session Imperial Stout grains 1921 - 1941
Year	OG	MA malt	SA malt	brown malt	amber malt	crystal malt	roast barley	oats	flaked maize	flaked rice
1921	1061.3		45.77%	13.46%	12.12%		9.42%		5.38%
1924	1061.4		47.00%	13.82%	12.44%		9.68%		5.53%
1928	1060.4	45.98%		13.79%	12.64%		10.34%		4.60%
1929	1060.7	27.15%	29.86%	10.86%	10.86%		8.14%		5.43%
1936	1060.4	40.43%	8.31%	5.26%	11.63%	6.65%	11.63%	0.28%	4.43%
1940	1055.4	43.29%		5.70%	10.25%	5.70%	11.19%	0.14%		9.11%
1941	1055.6	65.23%		4.30%	9.86%	5.02%	10.04%	0.18%
Sources:
Barclay Perkins brewing records held at the London Metropolitan Archives, document numbers ACC/2305/01/608, ACC/2305/01/611, ACC/2305/01/614, ACC/2305/01/621, ACC/2305/01/623 and ACC/2305/01/624.

Sugars next.

Unsurprisingly, most version contain No. 3 invert and all caramel. The lactose in the wartime versions I suspect is there for the same reason as oats. Because they were selling some of the London Stout it was parti-gyled with as Milk Stout as well as Oatmeal Stout. So I guess those beer ware Session Imperial Milk Oatmeal Stout.

Someone is bound to have brewed something called that in the last 10 years thinking they were being innovative. As I keep saying, almost nothing in beer is genuinely new, other than hop varieties.

Barclay Perkins Session Imperial Stout sugars 1921 - 1941
Year	OG	no. 2 sugar	no. 3 sugar	caramel	Martineau BS	lactose	other sugar
1921	1061.3		12.56%	1.28%
1924	1061.4		11.06%	0.46%
1928	1060.4		12.26%	0.38%
1929	1060.7		7.24%	0.45%
1936	1060.4	1.48%	2.95%	1.05%	5.91%
1940	1055.4			0.95%		1.52%	12.15%
1941	1055.6		3.35%	1.55%		0.48%
Sources:
Barclay Perkins brewing records held at the London Metropolitan Archives, document numbers ACC/2305/01/608, ACC/2305/01/611, ACC/2305/01/614, ACC/2305/01/621, ACC/2305/01/623 and ACC/2305/01/624.

The other sugar in the 1940 version is probably No. 3 invert. They just don’t specify the sugar type in the brewing record.