Recipe: Prime Rib tips

An excellent resource for cooking with today's leaner meats is The Complete Meat Cookbook by Brude Aidells and Denis Kelly (1998, so it might be in your library.) Cookbooks even a couple of decades old give recipes based on much fattier beef than is raised today, and such old guidelines can ruin the meat we get now.

Briefly, for a standing rib roast of 6 to 12 pounds (a 3, 4, or 5 bone roast) The Complete Meat Cookbook recommends the following (a 14 pounder would be the same but perhaps need a few minutes more at each stage). Preheat the oven to 450F. Start the roast at that temp and after 15 minutes turn the oven down to 350F without opening the door. After about 45 minutes check the internal temp of the roast with an instant read thermometer. If it isn't up to 115F continue cooking. 115F at this stage will give you a mostly rare roast with medium to medium-rare end cuts. Or roast to 120-125F if you want mostly medium when it finishes standing.

Then LET IT REST, covered loosely with foil, for at least 15 minutes and up to 30 minutes. The retained heat will continue to cook the roast. They say, after 15 minutes, if you removed the roast at 115F, the internal temp will have risen about 10 degrees; after 30 minutes, the internal temp may even read 130F, which is still rare to medium-rare. If you cooked it to 120-125 before taking out the final temperature after resting would be correspondingly higher, giving you medium internal temps and well done end pieces.

The USDA guidelines for final temperature are all extremely conservative and with meat as lean as it is today, will ruin many things cooked to those guidelines. Bacterial contamination from the outside of a roast is rare indeed, but only you can decide what you are comfortable with.

My personal guideline is to err on the side of undercooking. It can always be sliced and reheated if it's too rare for anyone's comfort but it can't be uncooked once it's overdone.