Can you believe that there are still Barclay Perkins brewing records that I haven't processed yet? But it's true. Somehow I got stuck in the late 1920's and never even got to the early 1930's records.
This beer is in one of the unprocessed sets. It's not made any simpler by the fact that Barclay Perkins had several brewing books at this point: one for their main brewery, one for the Lager plant and one for their small-batch brewery. Milk Stout was made in the latter.
Which tells me straight off that they weren't selling a huge amount of Milk Stout. This batch was just 18.75 barrels. At a time when they were brewing their standard Mild in batches of 500 barrels or more. So clearly not a huge seller at this point.
I'm not sure what happened later, as it doesn't turn up it the next small batch brewing book. Looking at analyses, the OG was lower in the later 1930's, around 1048. Which is suspiciously similar to the OG of London Stout. My guess is that they simply added lactose at racking time to some of that.
The grist is pretty complicated, with four malts plus roasted barley. Barclay Perkins were unusual in that sense. Most London brewers went for black or chocolate malt. Given the percentages, you have to wonder if the amber malt was diastatic. Unusually for a Barclay Perkins beer there's no flaked maize. Perhaps just as well, given the small percentage of base malt.
For once the hop additions aren't a guess. There are three types of hop, Fuggles, Worcester and Goldings, with two added "at inch" and the rest after an hour. I take "inch" to mean when the copper was filled with wort.
I've upped the FG and OG by 3 points to account for the "Milk Stout sugar" primings added at racking time. These had at OG of 1150º and were added at the rate of two gallons per barrel. I'm taking this to be some sort of proprietary sugar that was mainly lactose*. I've upped the lactose amount accordingly.
* It handily says at the start of the brewing record that MSS (Milk Stout sugar) was 250º L. So about 65 SRM.