What is Prime Rib Roast?
Prime rib claims center stage during holiday season for a very good reason. It is the king of beef cuts. A bone-in prime rib roast is also called a standing rib roast, because you position the roast majestically on its rib bones in the roasting pan to cook it.
Beautifully marbled with fat, this roast is rich, juicy, and tender—a feast for the eyes and the belly.
How to Cook Prime Rib
It's also very easy to cook. You just start it in the oven at a high temperature to get good browning on the outside of the roast. Then, cook it at a lower temperature to make sure the meat in the center doesn't get overcooked.
Video: How to Make Prime Rib
Why Prime Rib is Classic for Occasions
There's usually something for everyone with this roast. The ends are well done for those who can't tolerate pink. The center should be a vibrant rare for those of us who must have our beef rare.
How Many People Does Prime Rib Roast Serve?
A full rack of prime beef is 7 ribs, which will easily serve 14 to 16 people (or more!). A full rack will not fit in my oven, so when I'm feeding a crowd, I cut the roast in half (3 ribs on one roast and 4 ribs on the other) and cook them in separate ovens.
As for estimating how big a roast you'll need, the butchers I've talked to say to estimate 2 people for every rib. In my experience, that's a LOT of meat!
For the roasts we get, and given that we are serving a lot of food in addition to the roast, 3 people per rib is fine. If you want to err on the generous side with plenty of leftovers, aim for 2 people per rib.
What Grade of Meat is Prime 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 percent more per pound, you will likely need to special order it from your butcher.
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.
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.
Favorite Sides for a Prime Rib Roast
- Horseradish Sauce recipe
- Yorkshire Pudding recipe
- Perfect Mashed Potatoes
- 10 Best Sides to Serve with a Holiday Roast
Older cookbooks will sometimes instruct you to remove excess fat from the roast. "Excess" fat is any fat more than an inch thick on the roast. Fat is what you need to give the roast flavor and to make it juicy and tender. Prime rib is expensive and you are paying good money for that fat, so leave it on. Your butcher should have removed any excess fat already.
The most important piece of advice I can give you regarding cooking a prime rib roast is to use a good meat thermometer! I recommend this ChefAlarm by ThermoWorks.
With a remote thermometer, you can tell exactly what the temperature of the meat is without having to open the oven door.
For the Prime Rib Roast:
1 (10 pound) standing rib roast, 3 to 7 ribs (estimate serving 2-3 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
For the Gravy:
1/4 cup fat and drippings from the pan
1/4 cup all-purpose flour
3 to 4 cups water, milk, stock, or beer
Salt to taste
Freshly ground black pepper to taste
Salt the roast and let sit at room temp:
Remove the beef roast from the refrigerator 3 hours before you start to cook it. Sprinkle it with salt all over and let it sit, loosely wrapped in butcher paper. Roasts should be brought close to room temperature before they go into the oven to ensure more even cooking.
Tie with kitchen string:
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.
Preheat the oven and season the roast:
Preheat your oven to 500°F (or the highest temp your oven reaches, if it's less than 500°F). Pat the roast dry with paper towels (pre-salting should have made the roast release some moisture), and sprinkle the roast all over with salt and pepper.
Place the roast fat-side-up in a roasting pan:
Insert an ovenproof meat thermometer into the thickest part of the roast, making sure that the thermometer isn't touching a bone.
There are so many variables involved that affect cooking time, this is why you should use a meat thermometer. A prime rib roast is too expensive to "wing it". Err on the rare side, you can always put the roast back in the oven to cook it a bit longer, if it's too rare for your tastes.
Brown the roast at high temperature:
Brown the roast at 500°F (or as high as your oven will go) for 15 minutes.
Lower the oven to 325°F to finish roasting:
Reduce the oven temperature to 325°F. 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.
The actual cooking time will depend on the shape of the roast, how chilled your roast still is when it goes into the oven, and your particular oven. A flatter roast will cook more quickly than a thicker one. A chilled roast will take more time than one closer to room temp.
Roast in the oven until the thermometer registers 115°F for rare or 120° for medium rare, and 130°F for medium.
Check the temperature of the roast using a meat thermometer an hour before you expect the roast to be done. For example, with a 10 pound roast, you would expect 2 hours of total cooking time for rare (15 minutes at 500° and 1 3/4 hours at 325°). In this case, check after 1 hour 15 minutes of total cooking time, or 1 hour after you lowered the oven temp to 325°. (A benefit of using a remote thermometer is that you don't have to keep checking the roast, you'll be able to see exactly what the temperature is by looking at the thermometer outside of the oven.)
If the roast is cooking too quickly at this point, lower the oven temperature to 200°F.
Let the roast rest:
Once the roast has reached the temperature you want, remove it from the oven and place it on a carving board. Cover it with foil and let it rest for 15 to 30 minutes before carving. The internal temperature of the roast will continue to rise while the roast is resting.
Slice the roast:
Cut away the strings that were used to hold the roast to the rack of rib bones. Remove the bones (you can save them to make stock for soup later.)
Then, using a sharp carving knife, slice meat across the grain for serving, making the slices about 1/2-inch to 3/4-inch thick.
Make the gravy:
To make the gravy, remove the roast from the pan. Remove excess fat, leaving 1/4 cup of fat plus the browned drippings and meat juices in the roasting pan.
Place the roasting pan on the stovetop on medium high heat. Use a metal spatula to scrape up drippings that might be sticking to the pan.
When the fat is bubbly, sprinkle 1/4 cup of flour over the fat and drippings in the pan.
Stir with a wire whisk to incorporate the flour into the fat. Let the flour brown (more flavor that way and you don't have the taste of raw flour in your gravy.)
Slowly add 3 to 4 cups of water, milk, stock, or beer to the gravy. Continue to cook slowly and whisk constantly, breaking up any flour lumps.
The gravy will simmer and thicken, resulting in about 2 cups of gravy. (If you want less gravy, start with less fat and flour, and add less liquid.)
Season the gravy with salt and pepper and herbs to taste.
 According to Darrell Corti of the Sacramento specialty market Corti Brothers, irrespective of the USDA beef grading system, "prime rib" has always referred to that particular cut of beef, a cut which was popularized by restaurants in the 1920s and 30s, using quality or "prime" beef. Regardless of the USDA grading system, "prime beef" has historically referred to quality beef that is raised for consumption with good fat marbling, white fat, and bright red meat, as opposed to tough or lean beef from an ox raised for work.
What's the Difference Between USDA Prime and Choice?
Basically, more fat marbling throughout the meat. As you can tell from the following photos, Prime Grade has much more fat marbling throughout the meat than the Choice Grade.
With the current USDA grading system, "Prime" is the label given to the highest grade, and "Choice" the next highest; both are high quality grades. Because of high cost and fewer sources over the past decade or two, USDA Prime Grade prime rib has been replaced by most markets with USDA Choice Grade prime rib roast. A USDA "Choice" grade standing rib roast has become what most people buy when they buy prime rib in America.
Choice grade standing rib roast:
USDA Prime grade standing rib roast:
|Nutrition Facts (per serving)|
|Amount per serving|
|% Daily Value*|
|Total Fat 128g||164%|
|Saturated Fat 52g||260%|
|Total Carbohydrate 3g||1%|
|Dietary Fiber 0g||1%|
|Total Sugars 0g|
|Vitamin C 0mg||0%|
|*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.|