OK, admittedly I am a newbie and will only be trying my 1st all grain batch with my next brew, so hopefully this is just a really stupid simple question.
I note that the recipe that I am using is for a 6 gallon batch. It automatically calculates a boil volume of 6.87 gallons based on a 60 minute boil. The problem that I have is when I look at the brew sheet, it says (using 1.1 qt per lb of grain in an imperial IPA) to do a 20 qt infusion, and then sparge with 4.04 gallons. Doesn't this make 9.04 gallons???? How does my pre-boil volume come out to 6.87 gallons then? If it is retained water in the mash, I really can't imagine 18.25 lbs of grain seriously holding onto 2.18 gallons of sparge water, right?
Anyone know what is going on?