I am trying to figure out how I undershot my gravity on the last brewday. I am currently looking into grain absorption rates. Beersmith suggested that I would absorb 1.63 gallons from 13.5 lbs of grain. From my calculations taken throughout the day, I found that I only absorbed 1.25 gallons. I have a few questions. Will the crush of the grain greatly affect the absorption rate? Also, in attempts to dial in my profiles in Beersmith, is there a place to adjust the absorption rate so that it is more accurate the next time I put a recipe together? Finally, would the shape and size of my mashtun have any affect on this rate? I now understand that I should have simply done a 35 min boil before adding the hops to reach my desired OG. I am still learning and tweaking this new software. Thanks in advance for any advice.