I smoked a 13 pound brisket today.Last weekend I smoked a 10 pound brisket.Both were choice. Although there is only a 3 pound difference,you would think the 10 pounder would get done before the other,but it was not the case. Both were smoked at 225 deg. and the 13 lber finished about an hour and a half before my 10 did. In both cases,I started poking them at 195 degrees and they were done,it just took the heavier one less time to get there. It just goes to show what Okie always says,"It's done when it's done"! P.S Making burnt ends as we speak.