Originally Posted by Kaiser
Batch size is what you want it to be. If you see brewhouse efficiency as the efficiency into the boil kettle (as it is actually defined in many other sources), set batch size to your post boil volume. If you want brewhouse efficiency to be the efficiency into the fermenter, set batch size to your expected fermenter volume.
AHHHH... After playing at home with Beersmith this makes more sense
I think I am going to leave my batch size as 5.25 Gal in Beersmith, but set my Brewhouse Eff to a lower number(not the 70%) as stated in the book. For example, when I copy a Recipe from a book or something, I will use a lower Brewhouse Eff than the Recipe assumes until the Beersmiths' estimated OG matches what the book or magazine is calling for. THEN I will only really care about the "Efficiency into Boiler" number that Beersmith displays, which actually should match what the efficiency of the recipe I am copying from is using.
So basically, my big epiphany is that most recipes in books assume efficiency is calculated with post boil volume in the kettle... Beersmith assumes Brewhouse Efficiency uses post boil volumne into Primary Fermentor! (Obviously a lower number).
My "Brewhouse Efficiency" may *look* crappy (About 65%), but my typical "Efficiency into Boiler" number I think is actually pretty good, usually around 75%.