Prime Rib Roast: The Slow-Roast Method

Slow-roasted prime rib roast recipe cut on a wooden board
The Spruce
Prep: 16 hrs
Cook: 5 hrs
Total: 21 hrs
Servings: 4 to 8 servings
Nutritional Guidelines (per serving)
1949 Calories
156g Fat
0g Carbs
128g Protein
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Nutrition Facts
Servings: 4 to 8
Amount per serving
Calories 1949
% Daily Value*
Total Fat 156g 200%
Saturated Fat 62g 310%
Cholesterol 471mg 157%
Sodium 397mg 17%
Total Carbohydrate 0g 0%
Dietary Fiber 0g 0%
Total Sugars 0g
Protein 128g
Vitamin C 0mg 0%
Calcium 74mg 6%
Iron 14mg 76%
Potassium 1838mg 39%
*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.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)

There's just nothing like a slowly roasted prime rib for a holiday meal or special event. This recipe only requires four ingredients but provides a deliciously tender standing rib roast. 

Prime rib is a large piece of meat, but just because it's big doesn't mean you can treat it roughly. It's big, but because it's from the beef rib primal cut it's also tender. As with anything tender, it's best to be gentle with it. To a tender rib roast, a hot oven acts like a hand squeezing water out of a sponge. However, instead of springing back like a sponge, ​the meat stays squeezed. and you're left with a dry, shrunken roast.

That's why the best way to avoid mistakes when cooking prime rib is to roast it gently. A low temperature doesn't squeeze the moisture out. There's little to no shrinkage, and the juices stay in the meat. The result: juicy, prime rib perfection.

The only catch is that the oven doesn't get hot enough to brown the exterior. So this recipe requires you to sear the roast directly in the roasting pan, across two burners on the stovetop. Make sure you have a heavy-bottomed roasting pan that's suitable for the stovetop.

This technique will work equally well for either a bone-in or boneless rib of beef of between five and 10 pounds. For a bone-in prime rib, figure two servings per rib, while a boneless roast will yield two servings per pound.

Enjoy your prime rib with a side of mashed potatoes and asparagus, or whatever your favorite sides are. 

1:20

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Ingredients

  • 1 (5- to 10-pound) boneless or bone-in beef rib roast, trimmed and trussed

  • Kosher salt, to taste

  • Freshly ground black pepper, to taste

  • 2 tbsp canola oil

Steps to Make It

  1. Gather the ingredients.

    Prime rib roast ingredients

    The Spruce

  2. Heat the oven to 200 F. Set your roasting pan across two burners on your stovetop over medium-high heat. Add the canola oil and get it smoking hot.

    Roasting pan with oil in it

    The Spruce

  3. Then add the roast and carefully sear it on all sides, using tongs to turn it. Sear it for a total of 7 to 8 minutes until it's nice and brown all over.

    Prime rib roast on oil on pan

    The Spruce

  4. Season the roast generously with kosher salt and freshly ground black pepper. For a boneless prime rib, put a roasting rack in the pan and then set the roast with the fat-side up. With a bone-in prime rib, you can skip the roasting rack and set the roast bone-side down in the roasting pan.

    Generously seasoned roast searing in a roasting pan

    The Spruce

  5. Insert a digital probe thermometer into the deepest part of the meat, taking care not to hit bone. Set the temperature alert to beep when the meat hits 128 F (see note below).

  6. Roast until the temperature reaches 128 F, which will be another 2 1/2 to 5 hours, depending on the size of your roast.

    Prime rib roast with thermometer

    The Spruce

  7. Remove the roast from the oven, transfer to a cutting board, and cover it with foil. Leave the thermometer in and let the meat rest for 20 minutes.

    Roast wrapped in foil on a cutting board

    The Spruce

  8. Once you take the meat out, the temperature should nudge up to 130 F, which is perfect for medium-rare, and within 20 minutes or so it will drop back down to 120 F. At that point, it's fully rested and ready to slice and serve.

    Prime rib roast with a digital probe thermometer on a wooden cutting board

    The Spruce

  9. Serve and enjoy.

    Tips

    • The night before you're going to roast, unwrap the meat and let it sit in the refrigerator, uncovered, on the ​sheet pan with a rack. This will allow some of the surface moisture to evaporate, making it easier to get a beautiful brown crust when you sear it.
    • Three hours before you're going to roast it, take the meat out and set it on a sheet pan (to catch any juices) at room temperature. This step is important. If the meat is ice cold, the technique won't work as well. (And you don't have to worry about the meat going bad. Any surface bacteria are going to get seared immediately.)
    • If you prefer a medium prime rib, take it out at 135 F with a target temperature of around 140 F. Either way, you'll still want to rest the meat until it comes back down to 120 F before carving it.
    • If you don't have a digital probe thermometer, a standard thermometer will do. Just keep an eye on the time and check the roast after about 2 hours.

    What to Serve with Prime Rib

    Here's a simple au jus recipe you can make while the meat is resting. Or try this creamy horseradish sauce. Prime rib is also great with sides such as mashed potatoes, glazed carrots, green beans, and creamed spinach.



    How to Store and Freeze Prime Rib

    Prime rib will keep in the refrigerator, tightly wrapped in plastic or foil, for 3 to 5 days. Individual slices are best eaten in salads or on sandwiches. You can also freeze prime rib for up to 3 months. Wrap it tightly in foil or use a vacuum sealer if you have one. Let it thaw in the refrigerator. Heat it in a low oven (about 300 F) until completely warmed through, and then give it a quick sear in hot oil on the stove top to add some flavor to it again.