Prime Rib Roast: How to Buy It at Safeway and Roast It Right

Prime rib, standing rib roast, and ribeye roast

These all come from the same place: the rib section of the steer, the same cut ribeye steaks come from. The names describe how it's sold.

A standing rib roast (or bone-in beef rib roast) still has the rib bones attached. "Standing" just means it stands on its bones in the pan. This is the classic holiday prime rib.

A ribeye roast (or boneless rib roast) is the same meat with the bones removed. It's easier to carve and cooks a little faster.

Prime rib is what the roast is called once it's cooked and on the plate, and what most people search for. You won't always see "prime rib" on the label, so look for "rib roast" instead.

USDA Prime vs. Choice

The word "prime" in prime rib doesn't mean the beef is USDA Prime grade. Grade is a separate thing, printed on the label.

USDA Prime is the top grade, with the most marbling, and only a small share of beef earns it. Most supermarket rib roasts are USDA Choice, which is still well marbled and makes an excellent prime rib, especially from the rib section. If you see Prime-grade roasts, expect a richer, more buttery result and a higher price. Select is leaner and less forgiving, so don't take it past medium-rare.

Whatever the grade, look for even white flecks of fat through the red meat, a firm cap of fat on top, and a bright red color.

Pro tip: Ask the meat department whether they can cut the bones off and tie them back on. You get the look and insulation of bone-in and a roast that's easy to carve. Call ahead in holiday weeks, since the meat cutters are busy and may not be on duty all day.

Bone-in or boneless

Bone-in roasts look more dramatic on the table, and the bones shield the meat from the bottom of the pan so it cooks a bit more gently. You pay for the bone weight, so you need more pounds per person.

Boneless ribeye roasts cook more evenly, slice straight through, and give you more servings per pound. If it's your first prime rib or you're nervous about carving, boneless is the easier choice. If you want the classic look on the table, go bone-in.

How much prime rib per person

For a bone-in roast, plan on about 1 pound per person, or one rib for every two people. A 3-rib roast (about 6 to 8 pounds) serves 6 to 8.

For a boneless roast, plan on about ¾ pound per person. If you have a lot of sides or kids at the table, ½ pound each is usually enough. If you want leftovers for sandwiches, add a pound or two.

A whole rib section has 7 ribs. Roasts from the end nearest the loin (sometimes called the first cut or small end) have a bigger, more even eye of meat and less fat running through it, so the slices look neat. Roasts from the end nearest the shoulder (the second cut or large end) have more fat between the muscles and a thicker ribeye cap, the rich, tender strip around the outside that a lot of prime rib fans fight over. Ask the meat department which end you're getting if it isn't on the label.

Thaw it in the fridge

If your roast is frozen, thaw it in the refrigerator, never on the counter. Allow about 24 hours for every 4 to 5 pounds, so a 3-rib roast needs about two days. Once it's thawed, cook it within 3 to 5 days, counting any days it spends dry-brining.

Salt it a day or two ahead

Salting early (a dry brine) seasons the meat all the way through and dries the surface so it browns better. Use about 1 teaspoon of Diamond Crystal kosher salt per pound, or ½ to ¾ teaspoon of Morton kosher salt, which is denser. Rub it all over, set the roast on a rack in a rimmed tray, and leave it uncovered on the bottom shelf of the fridge, away from ready-to-eat food, for 1 to 2 days. By roasting day the surface will look dry and a shade darker, which is what helps it brown.

Add black pepper, garlic, and herbs on roasting day. Pepper and fresh garlic can scorch over a long cook, so a little goes a long way.

Pro tip: No time for a dry brine? Salt it generously right before it goes in the oven. Salting 20 minutes to a few hours ahead without the overnight rest can leave the surface wet, so either do it the day before or right before roasting.

Tie it and take the chill off

Tie a boneless roast with kitchen twine every inch or two so it holds a round, even shape and cooks evenly. Bone-in roasts that the meat department has cut and tied are ready to go.

You can take the roast out of the fridge 30 minutes to an hour before cooking, but don't expect much from it. A big roast barely warms in the center in that time. It's mainly a chance to pat the surface dry and season it. Don't leave raw beef out for more than 2 hours.

What you'll need

A meat thermometer is the one tool you can't skip. Ovens and roasts vary too much to cook prime rib by time alone. A leave-in probe thermometer with a cord lets you watch the temperature without opening the oven. An instant-read thermometer works too.

You'll also want a heavy roasting pan with a rack (or let a bone-in roast sit on its own bones), kitchen twine, kosher salt, black pepper, and fresh rosemary, thyme, and garlic if you like an herb crust.

Classic method, step by step

1. Heat the oven to 450°F with a rack in the lower third.

2. Pat the roast dry. Rub with a little oil, then pepper and any herbs or garlic. Set it fat side up in the pan, bones down if bone-in.

3. Roast at 450°F for 15 to 20 minutes, until it starts to brown.

4. Turn the oven down to 325°F without opening the door. Keep roasting until the thickest part of the center reads 120 to 125°F for medium-rare (see the temperature chart below for other doneness levels).

5. Move it to a cutting board, tent loosely with foil, and rest 20 to 30 minutes before carving.

Cooking time per pound

For a 2- to 4-rib roast at 325°F after the initial sear, figure roughly 13 to 15 minutes per pound for medium-rare. Bigger roasts take fewer minutes per pound. As a rough guide to total time:

2 ribs (4 to 5 pounds): about 1¼ to 1½ hours.

3 to 4 ribs (6 to 9 pounds): about 1¾ to 2¼ hours.

5 to 7 ribs (10 to 16 pounds): about 2¼ to 3 hours.

Cooking time depends more on how thick the roast is than how much it weighs. A 7-rib roast is longer than a 3-rib roast but not much thicker, so it doesn't take twice as long. Boneless roasts cook a little faster than bone-in. Start checking the temperature 45 minutes before you expect it to be done.

Pro tip: Plan for the roast to be done 30 to 45 minutes before dinner. It needs to rest anyway, and the oven is free for sides like potatoes or Yorkshire pudding.

Reverse sear, step by step

1. Heat the oven to 225 to 250°F.

2. Roast the seasoned roast on a rack until the center reads about 120°F for medium-rare (115°F for rare). In a low oven the temperature only climbs a few degrees after it comes out, so you can pull it closer to your target. Plan on 2½ to 4½ hours depending on size, and start checking early, since home ovens run hot or cold at these settings.

3. Take it out, tent loosely with foil, and rest 30 minutes to an hour. Turn the oven up to 500°F (or as high as it goes) while it rests.

4. Put the roast back in for 8 to 12 minutes, until the outside is deep brown and crisp.

5. Carve right away. It has already rested, and it rises only a few degrees in the hot oven at the end.

What USDA recommends

USDA's safe minimum for beef roasts and steaks is 145°F, measured in the center, with at least a 3-minute rest. That lands at medium to medium-well. Many cooks serve prime rib rarer than that, and that's a personal choice. If you're serving anyone who is pregnant, elderly, very young, or has a weakened immune system, cook it to 145°F.

Check the label before you cook a roast rare. If it says mechanically tenderized, blade tenderized, or injected (with a marinade or solution), bacteria from the surface may have been pushed inside, so cook it to at least 145°F with a 3-minute rest. Ground beef needs 160°F.

Let it rest

Rest the roast on a cutting board, loosely tented with foil, for 20 to 30 minutes. A big roast stays hot well past that, so a little slack in the schedule is fine. Resting lets the temperature even out and keeps more juice in the meat when you slice. Pour any juice from the board into the au jus.

How to carve prime rib

For a bone-in roast, stand it on its end or lay it on its side and run a long, sharp knife along the bones to cut them off in one piece. (If the meat department cut and tied the bones back on, just snip the twine.) Turn the meat cut side down and slice across the grain into ½- to ¾-inch slices, or cut thick slices with one bone each if you prefer.

For a boneless roast, remove the twine and slice across the grain.

Save the bones. They're great for gnawing on the next day, or for making beef stock.

Easy au jus

While the roast rests, pour off all but a tablespoon or two of fat, keeping the browned bits and juices. If your roasting pan is heavy metal and safe on the stove, set it over medium heat (across two burners if it's big). If not, scrape everything into a saucepan. Add 1 cup of beef broth or dry red wine and scrape up the browned bits. Add 2 more cups of broth and simmer about 10 minutes until it tastes rich. Add any juices from the cutting board, then taste before salting, since drippings from a dry-brined roast are already salty.

If you reverse-seared, make the jus while the roast rests before its final blast, so the drippings don't burn at 500°F. If the drippings scorched or there aren't many, a packet of au jus mix stirred into the broth works fine.

For gravy instead of jus, cook ¼ cup of the fat with ¼ cup of flour for a minute or two, then slowly whisk in the 3 cups of liquid and simmer until thickened.

Horseradish sauce

Stir together ½ cup sour cream, 3 tablespoons prepared horseradish, 1 teaspoon Dijon mustard, a squeeze of lemon juice, and a pinch of salt. Make it an hour ahead so the flavors come together. Prepared horseradish varies a lot in heat, so add it a spoonful at a time.

Jarred horseradish sauce is a good shortcut. It's already creamy, so serve it as is or loosen it with a little sour cream.