Learn step by step how to make a smoked prime rib on a Pit Boss pellet grill and why this is such an easy way to prepare this ultimate rib roast.
What Size to Buy
Prime rib roast generally come with the bones removed, but then tied back on by the butcher for presentation and to hold them against the meat while cooking.
You will see some prime rib roasts with 3-4 bones and others with as many as 6.
Usually the roast will be about 2 lbs in weight per bone.
Consider buying 1 lb of prime rib roast per person to be safe. So that's roughly 1 bone per 2 people when looking at them broadly.
Most prime rib roasts can be found anywhere from 4-8 lbs.
At first, a pound per person may sound like a lot.
But remember, some water weight will be lost during the cook and you also have to factor in the weight of any bones and fat that doesn't get eaten.
So it really ends up being about an 8-10 oz portion per person once the prime rib is done cooking on the Pit Boss.
Prepare the Roast
Let's start with the #1 tip right off the bat:
Don't remove the strings before cooking!
These strings are holding the bones in place and you want to keep everything held together nice and neatly while the prime rib is cooking on the Pit Boss.
You shouldn't have to trim too much fat or do anything else to your prime rib.
This is a Top O' the Line cut of beef you paid for and your butcher should have trimmed it up, removed the bones, then tied them back in place like a beautiful meaty holiday present.
Did we mention not to cut the strings? 🙂
Seasoning a Prime Rib
When it comes to an expensive cut of meat like a prime rib, or ribeye roast, you want to keep the seasonings simple and let the meat shine through.
For our recipe below, we simply mix kosher salt, black pepper, fresh minced garlic, rosemary, paprika, onion powder and a dash of cayenne.
Ideally use a HIGH smoke point oil to help the rub adhere to the meat such as avocado or grapeseed oil, especially if you plan to reverse sear at the end of the cook as we go into detail on below.
If you want to just buy a quality beef rub for your prime rib, we are big fans of Bad Byron's Butt Rub Seasoning on smoked beef because it is heavy on flavor, and has no sugar.
It also works great anytime you are reverse searing of cooking something "Hot and Fast," and you don't want a sugary rub to burn at those higher smoking temperatures.
We apply a thin layer of the high smoke point cooking oil, then a generous amount of the rub.
After that, we like to wrap it in plastic wrap and refrigerate it for at least 2 hours, preferably overnight.
This gives the salt loads of time to penetrate the prime rib and really flavor it all the way through before you put it on the Pit Boss.
Choosing Wood Pellets
You have a lot of freedom when it comes to choosing the right wood pellets to smoke your Pit Boss prime rib.
However, mesquite and hickory will give a very aggressive smoke flavor and, unless you have a LOT of experience smoking with them, should probably be avoided on a nice cut of beef like this.
Alternatively, you can also go for a milder smoke flavor that will not overpower the prime rib by choosing oak or fruitwood pellets.
Pecan, apple, beech, alder, and cherry all give great results on smoked prime rib.
Don't forget you can mix them up too to create your own custom blend.
That's one of the great things about a Pit Boss pellet grill!
For a straightforward smoke right out of the bag, we are big fans of Bear Mountain Red and White Smoky Oak Pellets
For the best results, store your unused pellets in a sealed room temperature container like this 20 lb pellet container rather than in the Pit Boss hopper outside.
Pellets do not last forever, but will definitely last a LOT longer if stored indoors in a quality airtight container.
Set up the Pit Boss
We have previously covered how to season a Pit Boss, how to start a Pit Boss, as well as how to troubleshoot the smoke level of your Pit Boss.
So if you need a more in-depth review on how to use your Pit Boss for the first time, check those articles out first!
In order to cook ANYTHING well on a Pit Boss pellet grill, you need to first have a basic understanding of how a pellet grill works.
***Completely New to Using a Pellet Grill? No Worries!****
Hop over and check out this Complete Guide to Understanding How a Pellet Grill Works if you are interested in learning more in depth. We'll be here when you get back!***
Let the Pit Boss go through its start up process and once it has come up to temperature and stopped producing the thick white "start- up" smoke, put the prime rib either directly on the grill grates, or in an aluminum foil pan to help catch the juices and keep it contained.
We recommend initially setting up the smoker to cook at 250°F.
Remember, we are dealing with a LARGE piece of beef here and if we go TOO high, the outside will over cook and dry out before the inside comes up to our ideal medium-rare temperature.
250°F seems to be the sweet spot where its low enough that the outside doesn't overcook but also high enough that the prime rib roast doesn't cook for so long that it dries out.
If you really want to push the cook time, set it for 275°F, but definitely no higher than 300°F.
Monitor the Internal Temperature Closely
You HAVE to use a good instant read meat thermometer to know where the internal temperature is of your smoked prime rib while its cooking on the Pit Boss.
Ideally you want a good leave in probe thermometer like the Thermopro as well as a second instant read to spot check different depths and areas on the roast.
While we have used and recommended ThermoPro for years, lately we have also become big fans of the MEATER leave in thermometer.
It is extremely accurate and has an incredible 165 foot Bluetooth range and works right with your smartphone so you don't need to carry a separate controller around with you like many other remote thermometers require.
It's got a great free app that is constantly being updated and even has an algorithm to predict how much longer your type of meat will take to cook based on cooking temperature, target temperature, and current internal temperature.
It's like a GPS for your meat!
Anyways, back to our smoked prime rib roast...
We are going to slowly bring the internal temperature up to about 110°F, then crank the heat as hot as we can to reverse sear the prime rib until the internal temperature hits about 120°F and then remove it from the Pit Boss.
Perfect medium rare in the center means an internal temperature of about 130-135°F, and a good rule of thumb is to pull big roasts like this when they are 10°F shy of your target temperature.
You can't do all this without accurate thermometers. There is very little room for error when smoking a prime rib roast.
We are particular fans of this one from ThermoPro because of its durability and affordable price.
So keep it handy and use it often.
A general guide is that it will take about 15-20 minutes per pound to smoke a prime rib roast at 250°F up to 110°F.
So plan on a 6 lb prime rib roast to take about 90-120 minutes to initially smoke during the "Low" portion of the cook.
Then we will crank the heat for another 15-20 minutes depending how long it takes to raise the internal temperature the rest of the way up to 120-125°F.
Then you will need to let the meat rest for 45-60 minutes after cooking it before carving.
Unless you want those delicious juices running all over your cutting board instead of staying in the meat where you want them, you need to set aside time for the meat to rest, and a large piece of beef like a prime rib roast needs extra time.
"Reverse Searing" is just a fancy term for searing your meat at the very end, once it is pretty much all the way cooked through, in order to get a nice crispy exterior crust that you sometimes just can't get from low and slow smoking alone.
The great thing about most Pit Boss models is their DIRECT HEAT option. Most newer models come standard with a SearZone option allowing you a direct heat plate option much like the popular Grill Grate.
If you have an older model Pit Boss, then check out the Grill Grate Sear Station as another way to get the same results on your older model without direct heat. We also love using Grill Grates for hamburgers and steaks.
Make sure to measure for the right size for your Pit Boss.
If you wish to reverse sear the meat, you will want to smoke it at 250°F only until it reaches an internal temperature of about 110°F. At this point it will still be very, very rare in the center.
When you are ready for the searing stage, move your prime rib roast over the direct heat, using good sturdy BBQ tongs and good grill gloves, sear on each side for about 1 minute until the internal temperature reaches 120°F and/or the outside has become nice and sizzly and crispy.
Alternatively, if you don't have a direct heat zone on your Pit boss or don't want to mess with moving your roast around too much to sear on each side, then just crank the temperature to 500°F and let the exterior start to sizzle!
We are going to crank the temperature of our Pit Boss up as high as it will go right at the very end of cooking, and only for a few minutes, in order to get a nice, golden brown crust on the outside of our smoked prime rib roast without overcooking the inside.
You need to watch your prime rib roast VERY closely at this point as it may only need maybe 4-6 minutes total once the Pit Boss comes fully up to the new high temperature.
Watch for the exterior fat to begin to sizzle and crisp up, watch for the color to turn from grayish to medium-dark brown, and whatever you do, do no leave it unattended to burn or over cook!
Use your instant meat thermometer to make sure the internal temperature has reached 120-125°F and no further!
Remember, it will continue to rise another 10°F as it rests after you remove it.
Carving and Serving
You will then remove the smoked prime rib roast from the hot Pit Boss and let it rest.
DO NOT wrap it or cover it with foil or it will overcook from its own contained residual heat.
Let the smoked prime rib roast rest for 30-45 minutes before carving.
Once the smoked prime rib has rested you will want to cut the ties an remove them from the roast.
The roast should separate easily from the slab of bones where the butcher cut them apart.
Set the rib bones aside but do not discard them!
These are delicious and can be sliced and eaten like a rack of ribs or you can use the meat for other purposes.
Place the rest of the main prime rib roast on the cutting board.
Although we mostly slow smoked the prime rib for ideal even cooking, the portions closer to the outside will still be more done than the very center.
This is nice because as you slice you can give the more done pieces on the ends to those that prefer them.
Then give the more medium rare slices from the center to those that prefer their meat less done.
Use a good meat slicing knife and cut the prime rib roast into nice thick slices based on how many guests you are serving.
We particularly like this meat slicing knife from Mairico.
The outside slices will be more done than the very center if you have guests who prefer various levels of doneness.
Make sure to check out How to Reheat Prime Rib for those leftovers!
Pit Boss Smoked Prime Rib with Horseradish Cream
- 1 Pit Boss Pellet Grill
- 1 Cutting Board
- 1 Meat Slicing Knife
- 1 Aluminum foil pan
- 1 Instant Read Thermometer
- 1 Dual Probe Thermometer
- Pellets for smoking, preferably hickory and oak.
- 1 Prime Rib Roast bones removed but tied on 5-8 lbs (plan on 1 lb per person served)
Savory Beef Rub for Prime Rib
- ½ cup Kosher Salt
- ½ cup Black Pepper
- ¼ cup Fresh Minced Garlic about 10 cloves fresh
- 1 tablespoon Paprika
- 1 tablespoon Dried Rosemary or can substitute fresh rosemary, finely minced
- ½ tablespoon Onion Powder
- 1 teaspoon Dried Thyme
- Cooking Oil High smoke point oil like avocado or grapeseed oil
Horseradish Cream (optional)
- 1 cup Sour cream
- ¼ cup Horseradish
- 1 tablespoon Stone ground or dijon mustard
- ½ teaspoon Kosher Salt
- 1 teaspoon white wine vinegar
- Fresh cracked black pepper to taste
Season the Prime Rib
- Take prime rib out of the packaging but DO NOT cut and remove strings.
- Rub with a thin layer of cooking oil.
- Mix all the rub ingredients and thoroughly and coat the entire outside of the prime rib including the sides with the mixture.
- Wrap in plastic wrap and place in the refrigerator until ready to put on the Pit Boss.
Start the Pit Boss Pellet Grill
- Remove the fire pot from the bottom of the Pit Boss and clean out any ashes left over from the last cook. Replace it and make sure it is secured in place with the clips on either side. Also, wrap the drip tray in aluminum foil to limit cleanup needed later.
- Add your chosen pellets to the hopper, start the Pit Boss pellet grill and put it on the "Smoke" setting.
- If there are no pellets in the auger, hold the "Prime" button until you hear pellets begin falling in the fire pot. This will speed up the auger to prime it full of pellets before you start preheating.
- Once the Pit boss begins to produce thick white smoke, let it run for about 5-7 minutes until the smoke turns more of a clearish blue color. This means the fire rod has fully heated up to burn the pellets more cleanly.
- Next, set the temperature to preheat the Pit Boss pellet grill to 350°F. We will drop this temperature before we start cooking.
- Fill an aluminum pan with water pan if you want to add extra moisture, and place it on the far left side of the Pit Boss pellet grill. Place a disposable bucket liner in the grease bucket as well if you want to limit cleanup later.
- Once the Pit Boss has come up to 350°F, drop the temperature on the control panel to 250° and clean the grill grates with a good grill brush and close the lid.
Smoke the Prime Rib on the Pit Boss
- Remove the prime rib roast from the refrigerator and remove the plastic wrap.
- Once the temperature of the Pit Boss comes down to 250°F after preheating, place the roast in the cooking chamber. Place a temperature probe into the deepest part of the rib roast.
- Cook at this temperature until the internal temperature reaches about 110°F.
Prepare the Horseradish Cream Sauce (optional)
- While the prime rib is smoking on the Pit Boss, you can prepare the horseradish cream sauce if you wish.
- Combine all the horseradish cream sauce ingredients in a small bowl and mix well to incorporate. Add extra salt as needed.
- Cover the bowl with plastic wrap and place in the refrigerator to serve with the prime rib later.
Reverse Sear the Prime Rib on the Pit Boss
- Once the internal temperature of the prime rib reaches 110°F, turn the temperature of the Pit Boss as high as it will go, preferably to 500°F.
- If your Pit Boss had a Direct Heat option, set it up now. Now carefully move the prime rib over the direct heat of the fire pot or the sear plate, depending on your model. Rotate to sear evenly on all sides, about 1-2 minutes per side using high heat grilling gloves and long handled BBQ tongs.
- Watch closely to make sure it does not burn and cook until the internal temperature rises to NO MORE THAN 120-125°F internally then remove from the Pit Boss.
Remove, Rest, and Slice the Smoked Prime Rib
- Let the smoked prime rib rest in an aluminum foil pan, uncovered for 30-45 minutes.
- Cut the ties off the prime rib roast and gently remove the slab of bones away from the rest of the roast. Do not discard, these are delicious.
- Place the main part of the prime rib on a cutting board and slice in thick slices for each guest.
- Serve immediately with horseradish cream sauce on the side.