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Dec 24, 2004 07:25 AM

Help! How long to cook Prime Rib

  • b

Okay...I've got a 14lb. six bone prime rib in the fridge for tomorrrow. I'll take it out of the fridge 2 hrs. before cooking. I intended to "sear" it in a 450* oven for 10-15 mins., then turn the heat down to 275* for the remainder of the cook time.

I've read 20 mins./lb. That almost 5 hrs. Could that possibly be correct? We like it rare-med. rare. I have a thermometer, but I'd like some idea of when it will be done so I can plan when we eat.

Any help at this late hour would be great.


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  1. My recipes all suggest about 15 per pound for rare. 20 minutes may be more like medium than medium-rare.

    1. If you are using the high temp/low temp method. Preheat the oven to 450 F. Place the meat on a rack in a roasting pan and season. Roast the meat for 25 minutes and then reduce the heat to 300F. For rare roast 16-18 minutes/lb. For Med. rare 18-20 minutes/lb. medium 20-22 minutes/lb. For rare a mat thermometer in the thickest part of the roast should read 140 F. when you remove it from the oven, med rare 150F. medium 160 F. The meat does not need to be basted and you are better off not opening the oven during the raosting.

      1 Reply
      1. re: Candy

        Oh my! Those temps are *way* off.

        Rare is about 120-127 degrees.
        Medium rare is about 128-135 degress.
        Medium is about 136-145 degrees.

        Just as important, though, the meat temperature will rise by about 10-12 degrees while it rests after you take it out of the oven.

        If you want medium-rare meat, take the meat out of the oven at about 118 degrees. Cover it with aluminum foil and let it rest on the counter for at least 15 minutes. You can monitor the temperature to achieve the desired level of doneness.

      2. This chart worked out perfect for my Rib last year.



          1. re: CG

            Thanks for posting this site, my prime rib was perfect! Cheers...Dawn

          2. Yes, that time (5 hrs) is the neighborhood you're looking at for a roast of your size cooked at 275* Such a large piece of meat will hold it's heat for a long time - and will be even juicier/more tender with a long resting time so you could plan on it being done well in advance of dinner time and then use the last half hour+ on doing other more pressing items. A note about carry over - since you're cooking on the low temperature side you will get less carry over than those that cook at *375 or even higher. Plan on 5* or 10* at the most. Cook's Illustrated cooks at 200* and expects 5* carryover. Joy of Cooking's slow method mentions cooking at 250* - with a carryover of 5*. Everybody's oven is different so keep that thermometer handy and monitor it well before the 5 hours is up. It should be very yummy - beautifully pink & juicy & tender all the way through.