Do I really need an instant-read meat thermometer?

Unless you’ve been smoking meats for twenty years, the most accurate way to tell if a pork shoulder or rib roast is cooked is to use an instant-read meat thermometer. Insert it deep into the center of the roast, but not so that it touches a bone. (Bones conduct heat and will give you an inaccurate reading.) Leave the thermometer there for about fifteen seconds—it will tell you the internal temperature (see the doneness chart).