It seems that, in some periods, unadulterated Porter wasn’t so much a rarity as totally non-existent. Except for maybe in the brewery tap of one of the London big boys. Whitbread, Truman, Barclay Perkins. People like that. Ordinary publicans weren’t to be trusted. If you were lucky, they just watered it. If you weren’t . . . . who knows what poisonous potions you’d consume?
But this one is different. Because it’s from Germany. An Altona trader in bottled beer was caught cutting Porter with Braunbier. Obviously something much cheaper. Analysis of his beer and Original-Porter (it’s not clear if that was imported Porter from the UK or locally-brewed stuff) showed around 25% Braunbier had been added. Found guilty, the trader was fined 30 marks. Which I guess was quite a lot of dosh back then.*
Here’s the table in a more readable, English-language format:
|confiscated Porter||Original Porter|
|degree of attenuation||59.23%||59.80%|
* "Übersicht über die Jahresberichte der öffentlichen Anstalten zur technischen Untersuchung von Nahrung und Genussmitteln im Deutschen Reich für das Jahr 1902" by Kaiserliches Gesundheitsamt, 1905, page 103.