Prime Rib is a Ribeye loin. It is the same loin used to cut ribeye steaks. The only difference is, to cook a Prime Rib you will cook the whole loin in the oven with low heat.
Where to find a Ribeye loin. Go to your local true meat market to buy a Prime grade ribeye loin. If you can’t find Prime, choose the most marbled Choice grade you can find. The size of the loin is determined by how many you will be feeding.
To calculate weight, every 1/2 inch cut is approximately 10 ounces of meat.
Example: If you are feeding 10 people, you will need approximately 8 pounds of Ribeye. After shrinkage during the cook there will be approximately 7.25 lbs of Prime Rib. Ten ounces per person equals 6.25 lbs of Prime Rib, so 7.25 gives you 1 lb of overage.
Salt and Pepper
Preparing the Ribeye.
Take the Ribeye loin out of the refrigerator and bring to room temperature. This will take approximately 2 - 2 1/2 hours. If you cook a loin that is cold in the center but warm on the outer edges, it will not cook evenly. Do not season the meat until ready to put in oven. When the meat is ready to put in oven, salt and pepper the fat side of the loin. (only the fat side). Do not over-season. Generously add Rosemary and Thyme to the fat side only. Place in a roasting pan.
Cooking time and internal temperature.
Preheat oven to 325 degrees.
For an 8 lb Prime Rib, cook 1 hour 15 minutes and check the internal temperature of the meat. Once the meat reaches 120 degrees, take out of the oven and let it rest for 30 minutes while continuing to cook another 5 - 7 degrees.
For medium rare the internal temperature of the meat should be at 125 degrees after resting.
Serve Walt Garrison Dippin’ Sauce for the perfect Au Jus.