How to Cook Prime Rib

Pay attention to the following details if you are cooking prime ribs for the first time. It’s not really that hard, but it’s crucial that proper steps are taken during the preparation stage.


  • Prime rib roast (keep at room temperature)
  • Butter (2 tbsp, keep at room temperature)


Trim off the fat but leave an inch of it on the ribs. This is necessary to protect the ribs when it’s being cooked. It’s also what gives the ribs flavor. Sometimes the butcher will cut the excess fat for you.

Take prime ribs out of the fridge a couple of hours prior to cooking. Keep the covering on but make it a little loose. Cold prime ribs will result in uncooked portions and uneven flavoring. After thawing you can dry the roast with a paper towel.

If you’re cooking prime ribs, thaw it in the fridge. When it has thawed, remove it from the fridge. Place it at room temperature for two hours. Turn on the oven and preheat to 450 F.


Take the roast and put some butter on both ends. Put the ribs on the pan (stainless steel and preferably 3 inches deep). The fat side must face up. Insert the digital thermometer in the thickest part.

Let the ribs sear for 15 minutes at 450 F. Next, lower the oven setting to 325 F. Every thirty minutes put some of the drippings in the pan onto the prime ribs.

When you’re cooking prime ribs, you should pay attention to the thermometer. In particular look at it often during the last 30 minutes. Remove the ribs from the oven when the thermometer reads 120 F.

Cover the roast with foil and let it rest for 15 minutes. A rest of 15 minutes will increase the internal temperature by another 5 degrees. It will keep cooking if rested for longer periods.

Carving and Serving

Get a long and thin knife. Make a slice at the feather bone area. Cut the ribs to the desired size. The usual serving size is half an inch thick.

Keep the bones if you want to make soup later on. This can be served with horseradish or sour cream. You can also use garlic and various types of sauces when cooking prime ribs.


A good ratio to use is two people for every prime rib. So if you’re serving 6 people you’ll need at least 3 prime ribs. For eight people, four prime ribs, and so on. The estimated cooking time will vary. 2 ribs will take about an hour. 4 lbs will take about 2 and ¼ hours.

Six ribs will take about four hours in total. If you want the roast rare, cook it at 125 F. For medium rare it should be 130 to 135 F. For medium it’s 140 and medium well 150 F. Anything over 160 F makes it well done.

Cooking prime ribs requires timing and precision. While it requires more from the cook, well-made prime ribs will make for a truly flavorsome meal.