How long do you cook a 40 pound steamship round roast?

A 40-pound steamship round roast typically requires about 12 to 15 hours of cooking time if using a low and slow method at 225°F to 250°F. For a medium-rare finish, aim for an internal temperature of 130°F to 135°F. It's essential to let the roast rest for at least 30 minutes before carving to allow the juices to redistribute. Always use a meat thermometer to ensure proper doneness.