A Guide to Prime Rib

If you’re going to splurge on this premium cut, make sure you’re cooking it right. Our guidelines will steer you toward perfection.

Published Sept. 20, 2017.

This holiday favorite is far too expensive to settle for dry, gray meat and a pale exterior. Here’s how to shop for prime rib, how to prep it, and how to ensure a deeply browned, substantial crust encasing a tender, juicy, rosy-pink center when you pull it out of the oven.

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What Is Prime Rib?

A cow has 13 ribs per side. Butchers refer to these ribs in ascending order from the front of the animal to the back. The first five ribs (1 through 5) are in the chuck section, the next seven (6 through 12) are the rib section, and the 13th is part of the loin. Ribs 6 through 12 are sold as prime rib.

Senior Editor Lan Lam breaks down a rib section into first and second-cut prime rib roasts.

How to Shop for Prime Rib

A whole seven-rib roast can weigh between 14 and 22 pounds, so butchers often divide the roast into two smaller roasts called the first cut and the second cut. Whichever cut you buy, count on one pound per person.


The more desirable of the two cuts, which is closer to the loin, consists of ribs 10 through 12. This cut is more desirable because it contains the large, single rib-eye muscle, which is uniform and tender.

Alternate names: Loin end, small end


This cut, consisting of ribs 6 to 9, is closer to the chuck end, which also means it’s made up of a mosaic of different muscles that don’t look as uniform and attractive when sliced. This cut also contains more connective tissue than a first-cut roast. Still, it’s an excellent roast that some cooks prefer since it contains more fatty pockets than the first cut, and fat adds flavor.

Alternate name: Large end

Prime Grade versus Choice Grade

Prime is the highest quality grade that the U.S. Department of Agriculture assigns to beef available to consumers. It indicates that the meat is heavily marbled with intramuscular fat (10 to 13 percent), which refers to the streaks of white fat between muscle fibers and which make it particularly flavorful and tender.

Choice, the second-highest grade of beef, is the grade issued to moderately marbled meat.

Prime-grade prime rib is a premium-quality roast often sold at high-end markets and butchers. Not surprisingly, we’ve found it more tender and flavorful than choice-grade prime rib, and we think it’s worth the high price tag—about 25 percent more than choice prime rib. (To read about our taste tests on prime-grade and choice-grade prime rib and whether or not to splurge on a dry-aged roast, visit Is Prime Rib Worth It?)

What Is Marbling?

Marbling refers to the desirable streaks of intramuscular fat in the lean muscle and is a primary factor when determining beef’s grade. The fat streaks are solid when cold but melt during cooking, enhancing the perception of juiciness and providing mouth-coating lubricity, which makes the meat seem more tender. Heat also causes the fatty acids to oxidize and form new flavor compounds that improve the flavor of meat and make it taste more complex.

How to Prepare Prime Rib

1. Cut Meat from Bones

While ribs help protect meat from overcooking and are great for gnawing on, they inhibit the seasoning and carving of the meat beneath them. To get around this, we cut them off the meat before seasoning it and tie them back on before roasting. We remove them again before carving.

2. Score Fat Cap

The thick fat cap insulates the meat as it cooks and crisps when exposed to high heat. Scoring (making shallow cross-hatched cuts down to, but not into, the meat) helps any seasonings penetrate the meat and encourages rendering.

3. Season Liberally and Early

Salt seasons and tenderizes the meat and helps it retain moisture during cooking. Given enough time and exposure to air in the refrigerator, salt also helps to dry out the meat’s surface so that it will brown deeply.

Guidelines: For a 7-pound, 3-rib roast, rub 2 tablespoons of kosher salt over the roast, including the side where the bones were removed and into fat cap slits, and refrigerate, uncovered, for at least 24 hours or up to 4 days. (Salting for longer than 4 days risks desiccating exterior unless roast is wrapped in plastic wrap.)

Why Season Meat With Kosher Salt?

We always call for seasoning meat with kosher salt, since the larger grains are easier to distribute evenly than the finer grains of table salt. To learn more about their different uses, visit Table Salt versus Kosher Salt.

How to Cook Prime Rib

Steakhouses use extreme measures to produce prime rib with well-browned, substantial crust and rosy, juicy meat from edge to edge—for example, roasting the meat at 180 degrees for most of a day and then blasting the exterior under a high-powered broiler or with a blowtorch. Our simpler method for Best Prime Rib produces equally good results.

Why It Works:

  • We start by salting the roast and refrigerating it uncovered for at least a day and up to four. The salt seasons the meat and enhances the beefy flavor while dissolving some of the proteins, yielding a buttery-tender roast. The salt and exposure to air together also dry out its exterior for better browning.
  • To further enhance tenderness, we cook the roast at a very low temperature (200 degrees) for 3 to 4 hours, or until it reaches 110 degrees, then cut the heat.
  • We leave the roast in the turned-off oven until it reaches 120 degrees (for rare) or about 125 degrees (for medium-rare). Holding the roast between 110 and 120 degrees accelerates the activity of enzymes in the meat that act as natural tenderizers, breaking down its tough connective tissue.
  • A brief stint under the broiler before serving and after resting ensures a crisp, flavorful crust.

Our Favorite Instant-Read Thermometer

The ThermoWorks Thermapen Mk4 takes all the accuracy and speed of the Classic Thermapen and adds a couple of nifty features that improve the user experience: its display now auto-rotates, lights up in low light, and wakes up when the unit is picked up. It takes a single AAA alkaline battery and is also more water-resistant than the Classic, capable of surviving a half-hour bath. Read the full review.

How to Carve Prime Rib

Prime rib is relatively easy to carve, once the bones have been removed. Carve only as many slices as you need. Leaving the rest of the roast intact will help it stay warm and retain flavorful juices.

  1. Cut twine and remove roast from ribs.
  2. Carve into 3/4-inch-thick slices and season with coarse sea salt.

Two Essential Carving Tools

These items make carving prime rib a breeze.

The two leading brands of kosher salt, Diamond Crystal and Morton, have different crystal structures, so they measure differently by volume. Case in point: One teaspoon of Diamond Crystal, which has a more open crystal structure, actually contains less salt than one teaspoon of Morton. Our recipes are designed with Diamond Crystal. Use this reference guide to convert measurements.

How to Reheat Prime Rib Leftovers

The key to reheating a roast is to fully warm it without drying out its exterior or cooking it beyond its original degree of doneness.

  1. Heat roast, uncovered, on wire rack set in rimmed baking sheet on middle rack in 250-degree oven until meat registers 120 degrees (1 to 1½ hours). Pat surface of roast dry with paper towels.
  2. Sear roast on all sides in hot, oiled skillet, 1 to 1½ minutes per side. (Do not sear cut ends.)

VIDEO: Watch Cook’s Illustrated Editor in Chief Dan Souza and Executive Food Editor Keith Dresser field your questions on how to cook the most impressive of all holiday roasts, prime rib. Follow our Facebook page to get Facebook Live notifications and more tips for holiday cooking.

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