Recipe Rewind: How To Cook A Prime Rib Roast

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a slice of butter and uncooked prime rib roast in a wooden tray, slicing cooked prime rib roast on second picture
slicing the roasted prime rib

With Christmas almost upon us, I am going back and bringing forth from my archives some of my more helpful or popular posts, and how to cook a prime rib roast is one of them.

Prime is the “grade” given to the meat, most roasts are actually just rib roasts, which on their own are delicious.

In Canada, we have Canada Prime, AAA, AA, and A. In the United States, they have Prime, Choice, Select and Standard.

It goes without saying that not all of us can get to a real butcher, so when looking for a roast, look for one that is well marbled, bright red meat and calculate one rib per two people (or 1/2 pound of meat). We always go slightly more because the leftovers are amazing.

Ingredients Needed:

prime rib roast

Ingredients in a wooden tray - prime rib roast and butter


Yup, that’s it. I don’t like any flavoring, salt, (which, by the way, can dry out the meat you are cooking, big no-no so you add it after) garlic rubs or the like. The butter has some salt in it of course, but the purpose is to actually help sear the meat at the beginning of the cooking process. You can search and try some rubs or toppings, there are a few out there, if you so desire.

Remove your roast from all its packaging and let it sit out for an hour until it’s about room temperature. Never, ever, cook a roast from frozen. The outside will be overdone and the inside will be raw. Absolutely a mess.

Take the butter and cover not only the ends, but if you don’t have a layer of fat on the top, cover that as well. When choosing prime rib, you actually want a layer of fat on the top. This helps make the roast oh-so tender. This roast didn’t have a layer, it was butchered too close, so I put a layer of butter on top.

Preheat your oven to 450 at this point.

covering the prime rib with butter

Once it’s covered, place on a wire rack in a pan deep enough to catch the drippings.

prime rib covered with butter on a wire rack in a pan

Now we want to sear the roast. Place it in the 450 degree oven for about 20 minutes. This picture reminded me that *embarrassed cough* I need to clean my oven.

buttered prime rib ready for roasting

It should be nicely browned (seared) on the outside now. This in theory seals in all the juices, and to be honest, when I do it this way I hardly have any drippings for gravy. So it really must do something to hold in the juices. Now you can turn the oven down to 325 degrees and roast.

buttered prime rib nicely browned on the outside

You cannot cook prime rib without a meat thermometer. You can’t. This masterpiece depends on a precise temperature, with it being pulled out of the oven at the exact right moment. This can’t be achieved without a thermometer. And to be honest, if you spend $50 on a roast, why on earth wouldn’t you pick up a $15 digital thermometer?

I measure on the outside where on the thermometer it will hit and put my fingers there.

measuring the rib temperature using a thermometer

Then keeping my fingers on the same spot, I put the thermometer in the middle of the roast until it reaches to where I measured. Make sense? Probably not. I usually just pretend I know what I am talking about.

baking the prime rib

Now place in the 325 degree oven for baking. Below are guidelines for roasting a prime rib roast. I wouldn’t waste the roast by going beyond medium rare personally. You want to pull the roast out a minimum of 10 degrees BEFORE you hit these temperatures. Once the roast is out, tent it with foil, and let it sit for about 20 minutes. The temperature will rise at least another 10 degrees if you cover it in foil. It also lets the juices set and flow back to the meat.

Prime Rib Roasting Internal Temperatures

Blue in the middle– 110 degrees – when the middle of the roast still “quivers”

Rare- 120 degrees in the middle

Medium-rare– 125- 130 degrees in the middle

Medium – 140 degrees in the middle. You don’t want it cooked this much.

Well-done– Don’t make me slap you for ruining a prime rib roast

So, you have pulled it out 10 degrees before it’s ready and tented it in foil for 20 minutes, right? Now it’s time to remove the bones. You want to slice along the curve of the bones just like below. I apologize for the poor, flashy picture. My husband isn’t that adept at my camera. It could be because I don’t share well. And definitely not my camera.

I know you all are wondering why I can’t do this and take a decent picture at the same time. I don’t know. I’m sorry. FAIL COOK.

removing the bones of cooked prime rib

And once again, not top quality pic. Good help is so hard to find these days. I mean honestly, I feed the man, make him do the dishes and his own laundry, don’t share my camera or my chocolate, and am nice to him, and nada on the good pictures. Sigh.

”You can see though, how pink it is in the middle. This was actually done to between Blue and Rare in the middle, for the first time ever, and it was fantastic. But I like rare. For the average person, I would cook it to rare to medium rare and no more.

slicing the roasted prime rib

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Karlynn Johnston

I’m a busy mom of two, wife & cookbook author who loves creating fast, fresh meals for my little family on the Canadian prairies. Karlynn Facts: I'm allergic to broccoli. I've never met a cocktail that I didn't like. I would rather burn down my house than clean it. Most of all, I love helping YOU get dinner ready because there's nothing more important than connecting with our loved ones around the dinner table!

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Comments & Recipe Tips Share a tip or comment!

  1. Thomas Johnston says

    Thanks for the knowledge.
    Marry Christmas From our family to yours.

  2. Troy Waldner says

    When you want to know how to cook for a large Family let me know. I do the cooking and she can do the cleaning. Ha ha not all men don’t know how to cook but I can teach most women how to! I’m was a single Dad to 4 children, now I’m a single Grandpa to four children. Even when I was married I was the cook for the most part. My prime rib is unique but as everyone that has had it says it the best they have had. My taco, and other items I cook.. my grandchildren love. They would now rather me cook them hamburgers, chicken nuggets.. ect.
    Please feel free to let me know how I can help you. The perfect prime rib starts the day before. I had some training from the prime rib king in Minnesota! Blackened and blaa blaa, salted..special rock salt. Then in the fridge for the night. Slow cooked until internal temp matches your desired 145 is the best let it stand for at least 20 mins. If you are cooking for more than 3 people. Have a medium skillet handy. Heat it up on high and brown or cook cut of meet to picky eaters desired overdonenes .. each to there own but happy eaters are the goal.
    I have a few extra stuff I do but if you are trying to please don’t be afraid to do what you think will work!

    Merry Christmas

    • su says

      please call would enjoy talking with you about food prep
      please leave message and mention your article
      Thank you

  3. Sharon Thomas says

    Merry Christmas toasts with paper cups of syrup of ipecac! LOL

  4. The Kitchen Magpie says

    Lol I see! Just knowing safe holding temps and stuff that is required for health regulations that makes me freak a little. You can’t determine that a stove would hold the temperature! Ugh. It would probably stay warm enough to encourage bacteria growth. Nothing like poisoning your entire family…. Merry Christmas in the ER! Lol

  5. Sharon Thomas says

    I was kinda of iffy when i read it that’s why I asked 🙂 Sent you a pm with the link

  6. The Kitchen Magpie says

    I ONLY use a meat thermometer! That sounds like guessing to me, you can’t determine the start temp of the roast inside, the size of the roast will totally affect cooking time, too many variables! I am cheap so I never risk a roast. AND that sounds like an incredibly UNSAFE method! OMG can we say food borne illness? There’s no way to make sure that each oven is at a safe temperature! I’m actually dying a little inside over that!

  7. Sharon Thomas says

    Must be prime rib post day lol I just saw another posted recipe, very similar to yours…500 degrees for 30 mins, then turn the oven off and leave the roast in for 2 hours…no opening the oven at all… and the roast will be perfect rare – medium rare. Have you ever tried this method? Your thoughts?

  8. SusanKinnon says

    This was the best I EVER EVER EVER cooked…thank you for this great recipie!!!!

    • thekitchenmagpie says

      SusanKinnon I just saw this! I am so glad that it worked out for you! There’s nothing like a prime rib roast done perfectly!

  9. Cindy says

    I followed your directions completely…first time my prime rib has ever turned out edible. Compliments all around the table too. Thank you Magpie. p.s. I think it’s time I checked out your other recipes and recommendations on how to…well how to, whatever it is you have to offer.

    • Karlynn says

      Oh fantastic! I don’t stray from that method ever. I am too scared to ruin an expensive roast by getting too adventuresome! I am really glad it turned out for you. I love when people comment on my How To posts, I truly do need to post more of them.

  10. A Canadian Foodie says

    Great tip and wonderful looking roast. Prime rib is THE ONLY roast. I love it. I stuff mine with garlic.

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