Thanks Mike, but when you say 'actual liquid volume inside fermentor', for me that includes all of the trub, hops etc which are not liquid...so are you saying use that volume i.e. 12L in my example above?

Yes, but surely the final volume of actual beer is a part of that equation. The volume I've given the calculator is 12L, but I actually ended up with 9L of beer. Presumably the calculation of 37 IBU's above is based on 12L, not 9L? I'm starting to think I've gone mad here...

Hi team, apologies if this has been asked a million times before (I did skim through but couldn't quite find this). Maybe it's obvious to everyone else, but my question is hard to define, but here I go. When I brew, I set the batch size to the 'fermentor volume' which is the amount I end up...