After taking the time to make the most perfect, tender prime rib, you may find that your dinner guests or family are late to the table and your main dish is getting cold. The best way you can keep prime rib and other meats warm right after cooking is to place it in the oven. Set it to low heat to keep the temperature of the prime rib steady, at least 140 degrees Fahrenheit until you are ready to serve.
Allow the just-cooked prime rib to rest for 30 minutes in the pan on the counter so that the juices will redistribute throughout the meat. This will make it more tender.
Heat the oven to between 170 and 200 degrees F.
Cover the prime rib in the pan you cooked it in with aluminum foil.
Place the pan in the oven until you are ready to serve.