Originally Posted by MichaelBrock
Thanks for the reply That much I understand though. My question is what water temperature does the "pre boil volume" assume? Due to the varying density of water with temperature it could make quite a difference. Seems like a simple question but I'm having trouble finding a definitive answer.
I don't know what it assumes, but even assuming a coolage percentage of 4% (if it's boiling hot), that's not much at all. Just call it "once the BK is up to boil volume" regardless of temperature and then build that into your boil off.
What I mean is this- use your measuring stick and see that you have 7 gallons as you finish the sparge (or whatever you start with). When your boil is finished, measure the amount you have left with the measuring stick and consider the difference all boil off, and then the shrinkage percentage will be dead on. Change the settings in Beersmith from "percentage boiled off in one hour" to "boil off volume" and use that amount from now on. Does that make sense? Temperature is totally out of the equation that way, since your system/temperatures won't vary by much in future batches.