I'm making http://www.food52.com/recipe... and it's a 9 pound pork shoulder that's been in the oven for 13 hours and has reached an internal temperature of 145. I've never cooked one before. Do I pull it out when the internal temperature reaches 160? Or does it need to continue cooking above that temperature to become meltingly tender? Help! I don't want an undercooked or tough shoulder tonight!