What Is Prime Rib?

A Guide to Buying, Cooking, and Storing Prime Rib

Prime Rib

The Spruce Eats / Lindsay Kreighbaum  

Prime rib is a classic roast beef preparation made from the beef rib primal cut, usually roasted with the bone in and served with a simple pan sauce made from its natural juices (au jus). The word "prime" is a legal designation that refers to the fact that the beef has been graded prime by the USDA. If the meat is not labeled as "prime" then it is simply a standing rib roast, or, if it is boneless, it is a rib-eye roast.

What Is Prime Rib?

The primary characteristic USDA inspectors look for when assigning grades (prime, choice, and select) is the amount of fat within the edible sections of the meat as well as the age of the cow; these criteria mean that prime beef will be tender, moist, and flavorful. The intramuscular fat, or marbling, is a source of flavor and moisture. Thus the more marbling there is, the higher the grade the meat will receive.

The other main factor is the age of the animal; younger animals will provide more tender meat. To be considered prime, beef cattle must be 9 to 30 months of age, although most are younger than 24 months.

Not all prime rib is prepared bone-in, but the bone adds flavor and moisture. Also, the rib bones make it easier to roast the prime rib since they act as a natural roasting rack. Even so, when cooked to perfection, a boneless prime rib can be every bit as sublime as the bone-in kind.

Prime Rib
The Spruce / Catherine Song 

How to Cook Prime Rib

The traditional way of preparing prime rib is to roast it medium rare, and there are a number of techniques (and mistakes to avoid) to accomplish this. In general, the cooking methods involve applying a high amount of heat for a short period of time in order to produce a flavorful brown crust on the exterior, then roasting at a lower temperature to get the internal temperature up to the desired doneness. Usually, the high-heat stage comes at the beginning, but it's possible to slow-roast a prime rib and finish it with a high-temperature sear at the end.

An important step to making a prime rib is letting the meat come to room temperature before putting in the oven. Because this is a large piece of beef, it will need a few hours on the counter to assure the center is no longer cold.


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What Does Prime Rib Taste Like?

Because the muscles in this part of the cow are not used very much, the meat of a prime rib is tender and juicy. The generous marbling and cap of fat help to create a rich piece of meat that is full of flavor. Once you taste a properly cooked, true prime rib, you will understand its high price tag.

Prime Rib Recipes

Because this cut of meat is a bit pricy, make sure you have a good recipe to work with. You can follow the traditional method and begin roasting in the oven at a high temperature to get a nice outer crust, and then finish cooking at a lower temp, or slow roast in the oven and sear the meat at the end. A prime rib can also be cooked on the grill or in the smoker. No matter which method you choose, limited ingredients with simple flavors are best to enjoy this special cut of meat to its fullest.

Where to Buy Prime Rib

Although it is called "prime rib," what you are essentially looking for in the meat case is a "beef bone-in rib roast." But if you would only like a roast that has been labeled "prime' by the USDA, you may have to special order. Prime bone-in rib roast may not be readily available at your local supermarket because of the high price tag—this cut of meat is not something that is purchased on a regular basis. Talk to the butcher at your market, or visit a specialty meat shop. You can also order prime rib online; just be sure it is a reputable site so you know you are getting what you pay for.

Although the fat provides flavor and juiciness, you don't want a roast that has more fat than meat. The back of the rib section—ribs six through 12—is generally leaner; it is often called the "first cut," "the loin," or the "small end." If the package labeling isn't clear, make sure to ask the butcher. When selecting size, calculate about two people per rib.

How to Store Prime Rib

If you are not preparing the roast immediately, you can keep it in the refrigerator for three to five days or the freezer for six months to a year. Just make sure it is wrapped well without any room for air between the meat and the plastic.

A cooked prime rib is best eaten right away, but if you have to hold it—or have leftovers—you can store it in the refrigerator for five to seven days, or freeze for up to six months. If you haven't sliced the entire roast, it is best to store it whole. If there is any au jus, drizzle over the meat before wrapping to keep it nice and moist.