Originally Posted by Schnitzengiggle
IIRC, most recipes are designed to have 5.25-5.5 gallons into the fermenter so you will end up with 5 total gallons when bottling. An approximate normal pre-boil volume for a 5 gallon batch would be 6.5 gallons boiling off approximately 1 gallon in the 60 minute boil, with ~5.5 gallons into the fermenter. Loss of .25-.5 gallons from trub in the primary fermenter.
Yeah, but you almost always leave stuff in the pot, unless you want all that protein and hops transfered into the fermenter. the hops(especially leaf) absorb alot of water. You also loose some to the wort chiller. Beersmith has adjustments for all that.
So when you boil off 1 gallon off of that 6.5 gallons, when you go to the fermenter, you have 5.5 gallons minus the loss to kettle trub and chiller. So it's not 5.5 gallons into the fermenter.
Maybe this is why alot of people have very high "brewhouse" efficiencies! It's supposed to include everything you lose. I'm just trying to figure out what people are meaning with the efficiency number they put into their recipes, typically. Extract/Lauter efficiency? Brewhouse efficiency? Some other value?