While several factors affect the cooking time of a pork shoulder, cooks should roast a 6-pound shoulder blade roast at 325 degrees Fahrenheit for 25 to 30 minutes per pound or 2 1/2 to 3 hours. Cook pork to a minimum internal temperature of 145 degrees Fahrenheit.
While many cookbooks provide cooking times for pork products, these are only estimates. A meat thermometer provides a more accurate measure of when the roast is ready. Modern pork has less fat than in times past, making a dry finished product a result of overcooking. A properly preheated oven and a good uncovered roasting pan ensures a crisp outer crust for better flavor. Allow the roast to stand several minutes before carving.