Rib Count - Approximate Weight + Estimated Cook Time
- 2 ribs, 4 - 5 lbs, 60 to 70 minutes
- 3 ribs, 7 - 8.5 lbs, 1 1/2 to 1 3/4 hours
- 4 ribs, 9 - 10.5 lbs, 1 3/4 to 2 1/4 hours
- 5 ribs, 11 - 13.5 lbs, 2 1/4 to 2 3/4 hours
- 6 ribs, 14 - 16 lbs, 3 to 3 1/4 hours
- 7 ribs, 16 - 18.5 lbs, 3 1/4 to 4 hours
Ingredients:
- Prime Rib Roast (Important: at room temperature to ensure even cooking)
- 2 tablespoons butter (room temperature)
- Instant-read digital meat thermometer
Instructions:
If the rib roast is frozen, let it thaw completely in the refrigerator and then stand at room temperature for two hours.
Preheat oven to 450°F.
Pat the roast dry with a paper towel. Leave the layer of fat on the roast to protect and baste during cooking.
Smear the cut ends of the roast with the butter. Place the roast (ribs down, fat side up) in a heavy stainless steel or other metal roasting pan with sides at least three inches deep. (Nonstick pans tend to yield fewer of the cooked-on bits that make the juice.) The rib bones are a natural rack; no need for a metal one.
Sear the rib roast for 15 minutes at 450°F, then turn the oven to 325°F for the remainder of the cooking time.
Every half-hour, baste the cut ends of the roast with the fat accumulated in the roasting pan.
Internal temperature, not time cooked, is the best test for doneness.
About 30 minutes before the estimated end of the roasting time, begin checking the internal temperature. Insert meat thermometer tip in the thickest part of beef, not resting in fat or touching the bone. Cook until rib roast reaches an internal temperature of 120°F. Remove from oven, cover with aluminum foil, and let sit approximately 15 to 20 minutes.
Remember, the rib roast will continue to cook as it sits. The temperature will rise to 125 to 130° F internal temperature (medium rare) at 15 to 20 minutes. If allowed to rest as long as an hour, the temperature will rise even higher.
*Note: To hold cooked roast until serving time, immediately turn off the oven and leave door ajar after removing roast.
Let roast sit (rest) 15 minutes on counter and then return roast to the oven, door closed, for up to an hour or even two hours for the biggest roasts. Check the temperature every 15 minutes. It will rise approximately 10° F at first, then gradually subside.
To carve: Using a long, thin, sharp knife, make one cut to slice off the large end bones. Then, slice off steak-sized pieces at the desired thickness.
