Slow Roasted Prime Rib

This post may contain paid links. If you make a purchase through links on our site, we may earn a commission.

My Slow Roasted Prime Rib is a melt-in-your-mouth holiday classic that makes a gorgeous centerpiece. Using only four ingredients, you can make this easy rib roast recipe with hardly any prep work! It’s so simple, even a total beginner to cooking prime rib can do it completely stress-free.

Jump to:

• Slow Roast Prime Rib
• What is Prime Rib?
• What is marbling on the prime rib?
• Slow Cook Rib Roast Ingredients
• How much prime rib per person should I serve?
• How to Season Prime Rib Roast
• How to Slow Cook Prime Rib Roast
• How to Cut a Prime Rib
• Slow Cook Rib Roast Temperature
• Slow-Cooked Prime Rib Expert Tips
• Storing Leftover Prime Rib
• How to Reheat Prime Rib
• Slow Roasted Prime Rib FAQ
• Sauces for Prime Rib
• What to do with Leftover Prime Rib
• Pin it for later!
• Recipe
• Reviews

Slow Roast Prime Rib

Out of all my recipes, my slow-roasted prime rib may be my most beloved. Considering how often I cook prime rib, from bone-in to boneless, smoked, grilled, air-fried, sous vide, and even in the pressure cooker, that’s saying a lot!

This dish is one of our most popular holiday recipes. Make it for yourself, and you’ll understand at first bite what makes this slow-roast prime rib so popular!

Low and slow cooking locks in all the juices for maximum flavor and tenderness. When you slow roast a prime rib, you will notice a very small amount of juice at the bottom of the roasting pan. All of the drippings remain in the roast, resulting in juicier beef than any other cooking method!

Once it is slow-roasted to the desired degree of doneness, put it in a high-heat oven for about 15 minutes before serving to achieve a beautifully crisp, browned crust on the outside, which adds tons of flavor. Serve this delicacy over my mashed potato recipe, and your guests will beg for more! This recipe is always a winner for Sunday dinner, too!

This was by far the best (and simplest) way to perfection with the
prime rib….Thank you…the BEST recipe for rib I’ve ever done and I’ve been cooking them for Christmas and Thanksgiving for over 50 years!!

Sarah

What is Prime Rib?

Like ribeye steak, prime rib is cut from the cow’s rib section. It is a meat cut with a great natural flavor and excellent marbling, making it very tender and tasty.

The word “prime” refers to the grade designated prime by the USDA. For true prime rib, look for the USDA prime grading. This is the highest grade of beef. There should be good marbling throughout the meat for the perfect prime rib. Marbling refers to the white lines of fat.

Prime rib is sold both on the bone as a standing rib roast, and boneless, as with this recipe for slow roasted prime rib and my recipe for boneless rib roast. Boneless prime rib cuts take less time to cook than bone-in, but both are delicious, so which you use is up to your preference and the amount of time you have for cooking prime rib.

What is marbling on the prime rib?

Marbling refers to white flecks and streaks of fat within the lean sections of beef, resembling a marble pattern. It is also called intramuscular fat. These flecks of fat are what give the beef its texture and amazing flavor throughout each bite because they melt into the meat as it cooks.

Slow Cook Rib Roast Ingredients

• Prime Rib: I’m using a boneless prime rib roast for this recipe. You can use a bone-in roast, but keep in mind bone-in roasts will take slightly longer to cook than boneless. Make sure to use a meat thermometer and my temperature chart to keep track of the internal temperature. This is the most important aspect to cooking a perfect roast!
• Olive Oil: You can use extra virgin olive oil, light olive oil, or avocado oil.
• Kosher Salt: Or sea salt flakes. I prefer sea salt, but kosher salt is excellent. Avoid using table salt.
• Black Pepper: Freshly cracked black pepper is best, but any will do!

This turned out perfect. Everyone absolutely loved it. This will the only recipe I use from now on.

Jay

How much prime rib per person should I serve?

A good estimate on how much beef you will need is ½ pound per person when the roast is part of a large holiday meal, or ¾ pound per person if it is the main feature. This recipe features an 8 pound prime rib that can comfortably serve 12-16 people, depending on serving size.

How to Season Prime Rib Roast

Before you cook your prime rib, you’ll want to season it ahead of time and let it absorb the flavor of your seasoning.

1. Salt the roast the day before and refrigerate overnight. Do not add the pepper or olive oil yet.
2. When ready to cook, rub the roast all over with 2 tablespoons olive oil and 1-2 teaspoons freshly cracked black pepper.

If you want to add a bit more to it, my prime rib seasoning is excellent!

How to Slow Cook Prime Rib Roast

1. Salt the roast all over with kosher salt the day before you plan on cooking it and refrigerate overnight, uncovered.
2. When ready to roast, preheat the oven to 200°F. Place the roast on a rack in a roasting pan. Rub the roast all over with olive oil and freshly cracked black pepper.
3. Place roasting pan in preheated oven until the center of the roast reads 120°F for medium-rare. This takes about 4 hours, but the time will vary depending on the size of the roast. Use a meat thermometer and cook to 5 degrees below your desired doneness.
4. Remove roast from oven and tent with foil to rest for at least 20 minutes. Turn oven temp up to 500°F.
5. Once the oven reaches 500°F, remove the foil and put the roast back in the oven. Cook until the outside is nicely browned and crisp, about 10-15 minutes. Transfer the roast to a cutting board and rest the roast at least 15 minutes before serving.

Slow-roasting flips the traditional method on its head! It’s easy and results in a delicious prime rib roast every time.

How to Cut a Prime Rib

1. Place your roast on a wooden meat cutting board with a juice groove and choose your own sharpest slicing knife.
2. Look at the direction of the grain of the beef and slice against the grain.

It is truly a personal preference if you slice thick or thin slices. Both work, so it depends on whether you want a steak-like experience or more of a roast beef-eating experience.

Slow Cook Rib Roast Temperature

It is always best to use a meat thermometer to make sure your roast beef is done perfectly to your liking. 

Doneness	Internal Temp
Rare beef temp	125°F
Medium-rare roast	135°F
Medium roast	145°F
Medium-well roast	150°F
Well-done roast	160°F

Slow-Cooked Prime Rib Expert Tips

• The night before, cut and unwrap the beef and set it in the refrigerator. Keep it uncovered on the ​sheet pan with a rack. This allows the surface moisture to evaporate and will guarantee a beautiful brown crust when you sear it.
• Three hours before roasting, take the beef out, place it on a sheet pan (to catch any juices), and keep it at room temperature. This step is key to an evenly roasted roast beef recipe.
• Rest for 15-20 before slicing. This will help keep in all the juices for the juiciest and moistest roast.
• We love serving it rare and using au jus gravy to finish cooking the meat. Perfection!

We have just started using the reverse sear method for steaks, but hadn’t thought of doing it with prime rib. Great tips in this recipe!

Pam

Storing Leftover Prime Rib

• Allow prime rib to cool slightly, then slice prime rib and store in an airtight container in the refrigerator for 3-4 days. Reheat according to directions below. If placing in the refrigerator while still warm, be sure to keep it away from dairy items that can curdle.

How to Reheat Prime Rib

I prefer to cook the meat medium-rare so it can easily be reheated without drying out.

1. Once you cut your beef into approximately equal slices, you can reheat by placing the meat in a microwave-safe dish.
2. Add a bit of leftover au jus or beef stock. Cover your dish with a paper towel and microwave on high for about one minute.
3. Continue to heat in 30-second increments until your roast reaches an internal temp of about 160 to 165º F.

You can also reheat your prime rib on the stovetop. Just add the sliced roast into a small pot with either leftover au jus or beef stock. Heat for approximately 5 minutes and serve.

Slow Roasted Prime Rib FAQ

Sauces for Prime Rib

• Horseradish Cream Sauce
• Garlic and Parsley Butter
• Black Truffle Butter
• Sage Butter
• Cowboy Butter

What to do with Leftover Prime Rib

• Penne Pasta with Cream Sauce
• Prime Rib Sandwich with Caramelized Onions and Remoulade
• Nachos with Prime Rib
• Prime Rib Pinwheels

Check out all my favorite recipes for using leftover prime rib!

As you savor the final bite of this slow-roasted prime rib, its buttery tenderness and rich, flavorful crust remind you why this classic dish is a true showstopper. Perfectly cooked to bring out its natural juiciness, it’s a masterpiece that turns any occasion into a celebration. Whether shared at a holiday table or a special gathering, this prime rib promises unforgettable moments and pure culinary bliss.

Recipe