Pork butt recipe

7 pound pork roast: Start with the heat at 450° for 20 minutes, then turn the heat down to 250°F and continue to cook for 7 to 8 1/2 hours until the middle of the roast registers 180°F. 8 pound pork roast: Start with the heat at 450° for 20 minutes, then turn the heat down to 250°F and continue to cook for 7 1/2 to 8 1/2 hours until the middle of the roast registers 180°F. 9 pound pork roast: Start with the heat at 450° for 20 minutes, then turn the heat down to 250°F and continue to cook for 8 to 10 hours until the middle of the roast registers 180°F. 10 pound pork roast: Start with the heat at 450° for 20 minutes, then turn the heat down to 250°F and continue to cook for 8 1/2 to 10 1/2 hours until the middle of the roast registers 180°F.