Determining the Doneness of Prime Rib
Prime rib is too expensive a cut of meat to leave to chance. Get a good meat thermometer and shoot for the internal temperature to match the level of doneness you like.
To figure out the total cooking time, allow about 11 to 12 minutes per pound for rare and 13 to 15 minutes per pound for medium rare.
Prime rib is best served rare or medium rare. Once it's overcooked, you can't un-cook it, though you can wait for it to cook a little longer.
- For a rare roast: 115°F.
- For medium rare: 120°F.
- For a medium: 130°F.
Let it sit for 15 to 20 minutes before serving. As the prime rib roast rests, the internal temperature will rise 5 to 10 degrees.