You'll come across two main schools of thought on cooking prime rib roast: slower cooking at lower temperatures for longer periods or a shorter cooking time at high temperatures. Cranking your oven up to 500 degrees Fahrenheit lets you get your prime rib on the table faster, and it's a relatively easy and hands-off process. Doing it right results in perfectly cooked beef that's great for holiday dinners or everyday meals.
What Is Prime Rib?
Prime rib comes from a specific section of the cow's ribs, specifically, the sixth through twelfth ribs. This seven-bone roast typically has lots of marbling in it, which helps keep it moist and flavorful. Even though it's called prime rib, not all cuts from this part of the cow are prime, which is the highest quality. When buying prime rib, check the grade to see if it's prime or the lower-choice grade of beef.
Since the entire prime rib section is often larger than what people want, prime rib is often cut into smaller pieces. First-cut roasts contain the tenth through twelfth ribs and are often more tender and uniform. Second-cut roasts include the sixth through ninth ribs and may have more connective tissue. Prime rib is an expensive cut of meat, so preparing and roasting it right means you get the most out of your money.
Preparing the Prime Rib Roast
A little prep work helps your prime rib turn out even better. Start with scoring the fat cap by cutting diagonal cross-hatch lines through the fat just until you reach the meat without actually cutting into the meat. This helps with rendering and makes it easier for your seasonings to soak into the meat.
Salt is an important part of the prep because it makes the beef tender, keeps it moist while it roasts and gets a deeper brown on the meat. Sprinkling kosher salt on the outside of the roast at least 24 hours before roasting helps maximize those benefits. Leave the salted prime rib in the refrigerator.
Put the prime rib on a rack in the roasting pan to keep it slightly elevated. You can also use carrots, potatoes and other veggies in the bottom of the pan to lift the beef. Add just a little water to the bottom to prevent smoking from fat that drips from the meat. You don't want the meat to touch the water at all.
Seasoning the Roast
The key to any 500-degree prime rib recipe is the seasoning phase, but it's also the most flexible. You can season your beef with your choice of dry seasonings, sauces and rubs. Popular flavors to go with prime rib roast include garlic, horseradish, rosemary, thyme, salt and pepper.
You can create a simple prime rib rub by mixing together crushed garlic cloves, salt and pepper. Add prepared horseradish to the mix if you want that flavor as well. You can also use a little olive oil mixed with your choice of herbs to spread over the outside of the prime rib. Choose the flavors you like best without going overboard with too much seasoning.
Roasting the Prime Rib
Preheat your oven to 500 degrees before you start roasting. Put your prime rib in the preheated oven, and roast it at 500 degrees for about 5 minutes per pound. If you're cooking a 8-pound roast, cook it for about 40 minutes.
Once your timer goes off, shut off the oven, but don't open the door. Leave the oven closed with your prime rib roasting away inside for another 1.5 hours. The residual heat continues cooking the meat and results in a perfect medium rare. This method won't work right if you open the door for any reason, so don't plan on baking any side dishes during the prime rib cooking time.
Serving the Roasted Meat
One perk of this cooking method is that it's ready to slice right out of the oven without letting it rest. If you're not quite ready to serve it yet, you can cover the meat with aluminum foil to keep it hot. Carve the beef into slices, cutting just as much as you need, and leave the rest to help it stay warm.