Prime Rib is expensive to buy and most people don’t get much practice cooking it. That can lead to costly mistakes right when you and your friends or family should be enjoying a perfect holiday meal. But the real question is not “how long to cook prime rib” but “to what temperature should I cook prime rib?”
Temperature Tip: Pull the prime rib at 125ºF for Medium Rare. Cooking at medium heat in an oven, this could take 3 hours or more.
Optimal tenderness and flavor are achieved at certain internal temperatures over time, not exact cooking times. This is because ovens will actually differ from household to household in heat flow and temperature maintenance. Also, cuts of meat will differ in size and fat content altering how long it might take a specific cut of meat to reach the medium-rare pull temperature of 125ºF. Verify that your prime rib has reached 125ºF at its thermal center with a fast instant-read thermometer, like the Thermapen Mk4.
More on Prime Rib Temperatures
with Key Temperatures
Cook Prime Rib