Prime rib refers to the king of beef cuts, the standing rib roast, “standing” because to cook it, you simply position the roast on its rib bones in the roasting pan, no need for a rack. Estimate 2 people served for every rib. Note that just because you are ordering a “prime” rib, it doesn’t mean that you are getting USDA Prime. Most “prime ribs” we get from market are actually USDA Choice quality. If you want USDA Prime prime rib, which has more fat marbling throughout the meat, and which can easily cost 50% more per pound, you will likely need to special order it from your butcher.
- One standing rib roast, 3 to 7 ribs (estimate serving 2 people per rib), bones cut away from the roast and tied back to the roast with kitchen string (ask your butcher to prepare the roast this way)
- Freshly ground black pepper
1 Remove roast from the refrigerator, loosely wrapped, 3 hours before cooking. Roasts should always be brought close to room temperature first, before they go in the oven.
Cookbooks often call for the excess fat to be removed. By "excess" fat they mean any fat more than an inch thick. The fat is what provides the flavor and what you are paying for with prime rib, so you want to leave it on. Your butcher should have removed any excess fat.
If your butcher hasn't already done so, cut the bones away from the roast and tie them back on to the roast with kitchen string. This will make it much easier to carve the roast, while still allowing you to stand the roast on the rib bones while cooking.
2 Preheat your oven to 500°F, or the highest it will go (our oven only goes up to 450°F). Generously sprinkle salt and pepper all over the roast.
3 Insert a meat thermometer into the thickest part of the roast, making sure it doesn't touch a bone. (Some meat thermometers require that you poke a hole first with a skewer, and then insert the thermometer.) Place the roast, fat side up, rib side down in a roasting pan in the oven.
4 After 15 minutes on 500°F, reduce the heat to 325°F. To figure out the total cooking time, allow about 13-15 minutes per pound for rare and 15-17 minutes per pound for medium rare. The actual cooking time will depend on the shape of the roast and your particular oven. A flatter roast will cook more quickly than a thicker one. So make sure to use a meat thermometer. (I recommend this remote ChefAlarm thermometer.) This is not a roast to "wing it". Error on the rare side.
Roast in oven until thermometer registers 115°-120°F for rare or 125°-130°F for medium.
Check the temperature of the roast using a meat thermometer a half hour before you expect the roast to be done. For example, with a 10 pound roast, you would expect 2 1/2 hours of total cooking time (15 minutes at 500° and 2 1/4 hours at 325°). In this case, check after 2 hours of total cooking time, or 1 hour 45 minutes after you lowered the oven temp to 325°.
Once the roast has reached the desired internal temperature, remove it from oven and let rest 20 minutes, covered with aluminum foil, before carving. The roast will continue to cook while it is resting.
5 With a knife or scissors, cut the strings which attach the meat to the bones. Remove the bones (save for making stock for soup. Then, using a sharp carving knife, slice meat across the grain for serving, making the slices about 1/4-1/2 inch thick.
To make the gravy, remove the roast from the pan. Place pan on stove on medium high heat. Pour off all but 2 tablespoons of the drippings to a separate container. Into the 2 tablespoons of drippings in the pan stir in 1 to 2 tablespoons of flour. Stir with a wire whisk until the flour has thickened and the gravy is smooth. Continue to cook slowly and stir constantly. Slowly add back the previously removed drippings (remove some of the fat beforehand if there is a lot of fat). In addition add either water, milk, stock, cream or beer to the gravy, enough to make 1 cup. Season the gravy with salt and pepper and herbs. (See also How to Make Gravy.)