- The prime rib you can buy in the supermarket is not graded prime by the USDA---it is actually choice. The three grades are prime, choice and select. Prime, the highest of the three grades has the most marbling, making the cut of beef the most tender cut you can buy. Real prime rib will have a USDA label stating what grade the cut of meat is.
- Because of its expense, most people only order prime rib at a restaurant or special order it from a butcher for special occasions such as Christmas dinner, an anniversary or a birthday.
- There is one type of prime rib, but it may come from the beginning of the ribs or from the end of the ribs. The best prime rib is cut from the 10th or 11th rib toward the back of the rib section. It is the smaller part of the rib section, but has more meat than a prime rib roast cut from the larger part of the rib section.
- Prime rib should be slowly baked. Start by preheating the oven to 450 degrees F. Roast the prime rib roast for 15 minutes, then turn the temperature down to 325 degrees F for the rest of the cooking time. If you want a rare roast, cook the roast until the internal temperature is 120 degrees F, then remove the roast from the oven, cover it with aluminum foil and let it rest for 20 minutes. A 3-rib roast takes about 1 ½ hours to cook and a 7-rib roast takes about 3 ½ hours to cook.
- When cooking a prime rib roast, remember to baste the ends of the roast with the juices in the bottom of the pan. Baste the ends every half hour. You should also leave up to an inch of fat on top of the roast. The fat is what helps give the roast its tenderness. After the roast is cooked, starting at the top of the roast and using a long knife, make one cut along the bone around the edge of the roast to remove the bones.
