Let's Brew - 1940 Whitbread Mackeson Stout

The third beer in Whitbread’s Stout parti-gyle was Mackeson. Which may sound a little odd, it being a Milk Stout. But, on account of the particular way Whitbread brewed Mackeson, that wasn’t a problem.

Because the lactose wasn’t added in the copper, as you might expect, but at racking time in the form of primings. Meaning it was no problem to parti-gyle it with other beers. Before the addition of lactose, the rate of attenuation of Mackeson was very similar to that of London Stout, somewhere around 70%.

For something which today would be described as a Sweet Stout, this version of Mackeson is surprisingly robustly hopped. And, even after the addition of the lactose, the rate of attenuation isn’t that low – still over 60%. Far greater than the ridiculously under-attenuated Sweet Stouts to be found at the time in Scotland. Meaning the finished beer probably tasted bitter-sweet rather than just overpoweringly sweet.

Whitbread were already brewing large quantities of Mackeson before the war. It was a beer very much in vogue and, like Bass and Guinness, was also sold in other breweries’ tied houses. A sure sign of a beer that was a cut above the norm.

1940 Whitbread Mackeson Stout
pale malt	9.00 lb	70.98%
brown malt	1.00 lb	7.89%
chocolate malt	1.00 lb	7.89%
flaked oats	0.10 lb	0.79%
No. 3 invert sugar	0.50 lb	3.94%
lactose	0.75 lb	5.91%
caramel 1000 SRM	0.33 lb	2.60%
Fuggles 75 mins	1.50 oz
Goldings 30 mins	1.50 oz
OG	1056
FG	1021
ABV	4.63
Apparent attenuation	62.50%
IBU	32
SRM	42
Mash at	150º F
Sparge at	170º F
Boil time	75 minutes
pitching temp	62º F
Yeast	Wyeast 1099 Whitbread Ale