To be honest, what I'm researching - brewing in the Netherlands during the war - is an optional extra to my book "Blitzkrieg!". Whose subject is really brewing in the UK during WW II. Leaving out the short Dutch section wouldn't really affect the core of the book. But it's still going.
Partly, because it would be a shame not to use material that's just lying there waiting to be picked up, sorted into some sort of order and squeezed into lovely tables. Mostly, however, because it shows what was happening on the other side of the fence. Over on the dark side. Allowing for some comparing and contrasting of the problems facing brewers.
As the relevant brewing books have been digitised by the Amsterdamse Stadsarchief, I've the luxury of having every page and every brew at my fingertips. The downside being that I've a shitload of material to sift through.
The pre-war stuff was a doddle. They only produced six beers and every batch was pretty much identical. Not so after 1940. The reason there's so much work is the same reason that "Blitzkrieg!" contains over 500 recipes. Wartime problems caused incessant tinkering. In strength, materials used, hopping rates. Constant change. Recording every single tweak is a right pain in the arse. It's taking me forever to get through 1942.
Up until June 1941, the war hasn't had much impact at Heineken. But from then on, it all goes downhill very quickly. Pils from 41.5% ABV to 3.2% ABV. A couple of months later, it's down to 2.8% ABV. In June of 1942, things turn really bad. Most Pils is just 1.4% ABV, though some is still brewed at 2.8% ABV and there's the occasional full-strength batch, presumably for the Germans.
And Pils was Heineken's strong beer. The other beers they continued to brew were all just 1.4% ABV. Watery stuff, indeed.
I should be able to drag myself through all the records this week. Unless I get distracted by Homes Under the Hammer or Come Dine with Me.