In a recent Twitter discussion about beer colour and colour scales, Ron Pattinson said how handy it would be to have a conversion chart between colour scales, ideally for Lovibond, SRM, EBC, Stammer (famously used by Professor Schwackhöfer in his 1876 analyses of beers sold in Vienna) and “Einheiten nach Brand”. In particular, the discussion revolved around the latter, as it’s one of the scales used in TGL 7764, East Germany’s industry standard for beer.
TGL 7764 is a particularly interesting industry standard, as it’s a rare example of beer styles getting standardized down to original gravity, bitterness, beer colour and even beer label colour and (in the case of Porter) microorganisms (Brettanomyces). And unlike style guidelines nowadays, like BJCP or the Brewers Association’s ones, this was actually prescriptive, i.e. it was compulsory for breweries in the GDR to follow these beer styles. I’m not aware of any other country doing that, but then, I haven’t really looked into it systematically.
Unfortunately, there does not seem to be a linear relationship between the Brand scale and EBC, so a simple conversion based on a few data points that we have from the 1980 and 1986 versions of TGL 7764 (which uses NFE, Brand, K450 and EBC) is not possible. Nevertheless, I’ve looked at the conversion between Stammer and the other common scales in the past and even put a simple table in my latest book, so I took this as a chance to at least present the data that I already have.
I will try and find out more about the Brand scale and if I do, I will update this table accordingly.
Stammer to Lovibond: °L = Stammer / 1.38
Lovibond to SRM: SRM = 1.3546 × °L – 0.76
SRM to EBC: EBC = SRM * 1.97