Can anyone tell me where to find the full text of Balling's article/book where his famous equation comes from? (I don't mind if it is in German).
I don't read German but from a bit of Googling I see references to "Die Bierbrauerei", though it looks like this appears in several works.
Regardless, searching Google Scholar I found this, which seems promising. I'm not 100% sure if this is what you're looking for but there are other books/papers by Karl Balling in the search results that may be it.