Finding the right smoking temperature is the key to how to smoke a prime rib roast.
When cooking a prime rib roast, whether in the oven or the smoker, your main goal is to evenly cook your roast from edge to edge.
A smoking temperature anywhere between 200 and 225 degrees Fahrenheit is the perfect temperature to ensure that your smoked prime rib roast is evenly cooked with no grey band of meat around the outside.
What is the best way to smoke a prime rib roast? Bone-in or boneless?
You can do it either way.
A boneless and bone-in prime rib roast will both turn out great as long as you maintain a gentle smoking temperature of between 200°F and 225°F.
Here is how to smoke a prime rib roast with an evenly cooked, juicy interior with a flavorful exterior crust. A condensed, step-by-step recipe is at the end.
What is a Prime Rib Roast?
A prime rib roast is cut from the rib primal part of a steer. The “prime” part of a prime rib roast has nothing to do with the USDA grading system and in fact, existed long before it.
The reason it is called a “prime” rib roast is that butchers consider it the best part (or prime part) of a steer.
Near the center of the roast there is a section known as the eye (longissimus dorsi), hence the name ribeye roast.
The eye is a much sought-after center-cut of beef known for its meatiness and exquisite marbling.
This prized eye section starts out small in the chuck section and gets progressively larger towards the loin end before terminating around the hip section of a steer.
This “eye” muscle runs down the back of a steer outside the ribs and through the chuck, rib, short loin, and sirloin primal cuts.
The eye is part of many popular beef cuts taken from each of these primal cuts. When it is in the chuck section it is known as the chuck eye, in the rib section it is the rib eye, in the short loin it is the top loin (or new york strip), and in the sirloin, it is the top sirloin cut.
A whole prime rib roast consists of seven ribs (ribs 6 through 12) and weighs on average between 15 to 20 pounds (7 to 9 kg). The prime rib roast pictured weighs over 18 pounds (8 kg)
It is also known as a standing rib roast because it stands on its ribs as it roasts as the rib bones keep the meat elevated off the pan.
Butchers will often cut the whole rib roast into two distinct cuts, known as the first cut and second cut.
(Please note that the rib roast is flipped over with the chuck end on the right side in the picture below whereas it was on the left side in the picture above.)
The first cut consists of ribs 12 through 10 and is prized for its larger eye section of meat.
A second cut consists of ribs 6 through 9 and the eye section gets progressively smaller the closer you get to the chuck end.
A whole roast can also be sectioned off into even smaller roasts consisting of just two bones.
Smoking a Bone-In Prime Rib Roast vs a Boneless Prime Rib Roast
Are there benefits to leaving the rib bones on prior to smoking a prime rib roast? There can be.
Do the bones add extra flavor? No, they don’t.
If left on, the ribs can act as an insulator against heat if your rib roast is placed properly in your smoker
You can use this to your advantage by placing the rib side closest to the hotter parts of your smoker, with the meat side closest to the cooler part.
To see if there were any benefits to leaving the ribs on versus removing them prior to smoking I decided to smoke both a boneless prime rib roast and a bone-in prime rib roast.
To do this, I portioned the 10-pound, four-bone, second-cut rib roast from the photos above into two, 5-pound roasts.
Next, I removed the ribs and some of the fat cap on one of the roasts.
I then tied the outside of the boneless rib roast with butcher’s twine into a more circular form for even cooking.
I also tied the bone-in rib roast to keep the shape of its meat somewhat in proportion with the boneless roast as well.
Both roasts were seasoned with salt and pepper and allowed to rest uncovered overnight on a rack over a pan or plate in the refrigerator.
Why is it a good idea to season your rib roast well in advance of cooking? Here’s why.
Salting Your Meat
It’s a good idea to salt your prime rib roast with kosher salt well in advance. Also known as dry brining, salting your meat ahead of cooking and allowing it to rest has many benefits.
These benefits include a more deeply and evenly seasoned roast as well as a juicier roast due to better moisture retention.
A more in-depth explanation of dry brining can be found in the post: How to Smoke a New York Strip Roast.
How much kosher salt should you use to season your rib roast and how long should you let it rest?
A general rule of thumb is a half teaspoon per pound of meat. You can go more or less depending on your personal preferences.
On a five-pound rib roast that equates to 5 1/2 teaspoons or 1.8 tablespoons of kosher salt (you can round up to 2 tablespoons).
To get the benefits of dry brining you will want to let your roast rest after salting for at least six hours, but preferably overnight up to 24 hours ahead of time.
The Best Temperature to Smoke a Prime Rib Roast
An evenly-cooked, rosy-pink interior is the goal when smoking a prime rib. A low smoking temperature is necessary to achieve even cooking throughout the roast.
A low smoking temperature of anywhere between 200°F to 225°F will allow the entire roast to come up to temperature slowly and evenly.
If you’re cooking a four-bone, 10-pound prime rib roast it is also a good idea to portion it into two sections as it is difficult to get such a large piece of meat to cook evenly from edge to edge.
You will get better results cooking two smaller roasts, with more of the meat exposed to smoke as well as less overall cooking time.
Smoked Prime Rib Time Per Pound
How long does it take to smoke a prime rib roast? It depends on the size of the roast and the smoking temperature.
Smoking a prime rib roast at 225°F will generally cook at a rate of 35 minutes per pound to get to an internal temperature of 120°F.
The time of cooking rate will go up if you smoke at a lower temperature. I smoked both the boneless and bone-in prime rib roasts around 200°F and they both cooked at a rate of 45 minutes per pound to get to an internal temperature of 120°F.
Both rib roasts weighed around 5 pounds the previous day before the removal of the bones on one making it a boneless roast.
The boneless prime rib roast weighed a little under 4 pounds after removing its bones. How did this affect the cooking time?
Calculating the cook times using the weight of each roast gives us a cooking rate of 47.5 minutes per pound for the boneless and 46 minutes per pound for the bone-in. (The average smoking temperature was a little under 200°F.)
That isn’t much difference in terms of the rate of cooking per pound but the bones did add an extra 40 minutes to the cook.
Did the bones add anything in terms of extra flavor or quality of the meat? Not really.
What is the takeaway from this then?
The key point is that it is very hard to overcook your smoked prime rib, whether it is bone-in or boneless, as long as you maintain a low smoking temperature of between 200°F and 225°F.
You can leave the bones in if you want, but it will add more cooking time and not much else to the finished product.
Carryover Cooking and Rare versus Medium Rare
There are people that consider cooking a prime rib to an internal temperature of 120ºF as overcooking it.
If cooked conventionally at a higher temperature I might agree with them.
The reasoning is that there will be the obligatory extra 10 degrees (or more) of carryover cooking after you pull your prime rib from the heat.
However, the amount of carryover cooking is less significant when cooking or smoking a prime rib at lower temperatures, such as 200ºF.
You can expect the internal temperature of your prime rib to increase by only 5 to 8°F while resting it after smoking it at a temperature of 200ºF.
Can you smoke your prime rib to an internal temperature of 110ºF or 115ºF? Yes, just be prepared for a final internal temperature bordering on very rare.
Smoking a prime rib at a temperature of 200ºF to an internal temperature of 120°F will give you a nice rare to medium-rare doneness from 125ºF to 128ºF.
There are many schools of thought about what is considered rare, medium-rare, etc.
There is usually an overlap of 5ºF in each category, some temperature charts are higher, some lower.
- Rare – 120ºF to 125ºF (48.8ºC to 51.6ºC)
- Medium-Rare – 125ºF to 135ºF (51.6ºC to 57.2ºC)
- Medium- 135ºF to 145°F (57.2ºC to 62.7ºC)
- Medium-Well- 145ºF to 150ºF (62.7ºC to 65.5ºC)
- Well-Done- Here’s a bottle of steak sauce for you.
The Final Sear: Finishing Your Prime Rib
You can certainly just smoke your prime rib, let it rest, then carve and serve it, but searing it over high heat at the end gives it a nice flavorful crust.
Should you rest the prime rib first before searing it or sear it after you pull it from the smoker?
I’ve done it both ways and have found little difference between the two methods.
Whether before or after searing, you still need to rest your prime rib before slicing into it.
Allow for 30 to 40 minutes of resting if you do decide to rest the prime rib whether before or after searing.
How long should you sear it for? All it takes is one to two minutes a side over high heat.
The sear can be accomplished in a large pan with some olive oil or butter, or on a grill, both methods work well.
Once you’ve achieved the desired outside appearance and allocated enough time for resting you’re ready to eat!
Here’s a step-by-step recipe.
Smoked Prime Rib Roast
- 1 Smoker or Grill
- Wood Chips or Chunks
- 5 lb Prime Rib Roast
- 2 tbsp Kosher Salt
- 1 tbsp Black Pepper
Additional optional seasonings
- 1 tbsp Garlic powder Granulated Garlic or minced garlic work as well
Fat for Searing Step (either or, not both)
- 2 tbsp Butter
- 2 tbsp Olive Oil
- Trim any excess fat from the roast and season roast with salt and pepper. Allow the roast to rest for at least 6 hours up to overnight.
- Set up smoker or grill for smoking at a smoking temperature between 200 degrees Fahrenheit and 225 degrees Fahrenheit. Add preferred wood chips or wood chunks to the fire. Place your rib roast in the smoker and insert a temperature probe in the middle to monitor the internal temperature.
- Smoke the prime rib roast until it reaches an internal temperature of 120 degrees Fahrenheit.
- Sear the outside of the roast in a large pan set over high heat or on a grill set for high heat for 1 to 2 minutes per side. Sear the roast in a pan using either two tablespoons of butter or olive oil.
- Rest the roast for 30 minutes. Carve and serve.