Most websites of trade associations are rather self-serving and lack much in the way of solid information. But the Cologne Brewery Association has a series of articles based on interviews with the late Hans Sion conducted in 1998. Sion was the inheritor of the brewery of the same name, and is credited with being the driving force in the rise of Kölsch after the Second World War to become the dominant beer in the city, having been a minor speciality before. Sion himself recalls having had to serve Würzburger Hofbräu in the family's own beer hall because lager was more in demand than their own Kölsch.
This snippet caught my attention.
"In the 1960s, Dr. Münder, who had worked at [the brewery called] Dom, brewed a pale beer at Guinness in Dublin. He actually managed to get the Irish to switch from their black stout to a paler beer. It was the same top-fermenting brewing process as with Kölsch. The pale beer sold quite well in Ireland."I was quite excited at this bit of information. I thought I'd hit on a forgotten relic of brewing history. A pale Rhine-style top-fermenting beer made by an actual German that took conservative 1960s Ireland by storm, yet unaccountably faded into history.
Then I realised Herr Sion was probably talking about Harp. Oh bugger.
Diageo confirms: "Working with German master brewer, Dr Hermann Muender, and local ingredients, Harp lager was created." And if I'd read this article on Harp beforehand, I'd have noticed the name.
I genuinely don't know whether Harp was actually top-fermented or bottom-fermented in its early days. Ron's article goes into great depth on the mashing regime (at least, the one used at Courage, which is not necessarily identical to the one Guinness used) but doesn't confirm what yeast was used. Plenty of breweries were making pseudo-lagers at the time with their usual yeast.
Herr Sion seemed to think it was top-fermenting, though I guess the old man, 87 at the time of the interview, could have been tricked by his memory.
It's more fun to think that the Kölsch brewer Dr. Münder was just embarrassed to admit to his colleagues back home that he'd been making lager. But this can't be the case either, because Cologne's breweries brewed Pils and Export as a matter of course until the 60s and 70s when Kölsch achieved the saturation of the local market it still enjoys today.
Maybe the truth is even worse … that Dr. Münder disliked the newly fashionable top-fermenting beer and went off to brew Harp by choice.