Cooking time for 15 lb prime rib

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A goof-proof Prime Rib Recipe!  This simple method results in incredible, perfectly cooked prime rib each and every time. All you need is two ingredients, a roasting pan and a thermometer!

Everything you need to know about cooking prime rib is right here in this post! From prime rib seasoning to prime rib cooking time, differences between various cuts of roast, and more. This easy recipe made the best prime rib in the world!

Prime rib is generally accepted as the alpha omega of all the beef cuts. And for a great reason! It is tender, loaded with flavor, and has the most delightful drool-worthy crispy fat layering the outside.

Cooking large pieces of meat can be intimidating, but what I’ve learned over the years is the bigger the better. 

I say that somewhat in jest, but also somewhat seriously. 

Large cuts of meat typically include a decent amount of fat content, which helps lubricate the meat throughout the cooking process and results in tender, delicious meat.

In addition, larger cuts are typically cooked for a longer period of time (the longer, the better 😉 ), again resulting in mouth-watering succulent meat.

To summarize: there is no need to be intimidated by the ol’ standing rib roast!

Here is everything you need to know about making an amazing prime rib roast!

What is Prime Rib?:

Prime Rib, also known as standing rib roast, is cut from the rib section of the cow. It has a great deal of fat on the outside of the roast, and a decent amount of fat marbled throughout the meat. This translates to flavor, amazing texture, and tender, amazing meat.

How to Make Prime Rib:

Step 1: Season the meat and bring it to room temperature.

First things first! Place the roast in a roasting pan (or large casserole dish) and sprinkle liberally with sea salt. Use your hands to pat the salt into the meat.

Before putting the meat in the oven, you want it to be room temperature, or as close to room temperature as possible. The best way to do this is simply to leave the roast on the counter in a roasting pan for 2 to 3 hours prior to baking. For a larger roast (8 to 10 lbs), you’ll need about 3 hours, and for smaller roasts, 6 to 8 lbs, 1 to 2 hours should do the trick.

If you’re pressed for time, you can bring the temperature of the meat up by placing it in a warm oven. Place the roast in the roasting pan, season it with sea salt and place it in a 200-degree oven for 10 to 15 minutes. For a 10-lb roast, go for about 15 to 20 minutes. If you notice the roast is starting to bake (the fat is rendering), pull it out, or roast it immediately.

Step 2: Bake at 500 degrees for 8 to 15 minutes.

Baking at a high temperature sears the outside of the meat, which locks the moisture inside and also creates the most delectable crust on the outside.

When you’re ready to roast the prime rib, preheat the oven to 500 degrees F.

Place the roasting pan with the prime rib in the oven and roast for 8 to 15 minutes, until the outside is deeply golden-brown. The amount of time depends on the size of the roast. For a 5 to 6-pound roast, bake for 8 minutes. For a larger, 10-pound prime rib, bake for 15.

Step 3: Decrease the Heat and Finish Roasting.

After the initial HOT flash, reduce open the oven to let out some heat and reduce the heat to 300 degrees F. For rare prime rib, bake for 11 to 14 minutes per pound. For medium-rare, about 15 to 18 minutes per pound. For medium, about 18 to 21 minutes per pound.

For the last 20 to 30 minutes, you can increase the oven heat to 325 to speed up the process. Just keep an eye on the temperature.

Be sure to use a meat thermometer to check the internal temperature of the meat for the desired result! 

Step 4: Rest!

Allow the meat to rest 20 to 30 minutes before you slice into it.

How to Cut Prime Rib: 

Prime rib roast has ribs on the bottom (if it came bone-in), which can either be served to your guests or removed.

If you’d like to cut the ribs off before serving, turn the roast on one side (after it has rested for 20 to 30 minutes!) and use a sharp knife to cut the bottom off (this will be about 1 inch).

You can serve the ribs or save them for soup!

Stand the roast back up and cut against the grain. You can slice thin layers, or cut the prime rib roast into ribeye steaks. I prefer going the steak route so that each person has a nice portion of meat and an amazing crispy fat exterior.

Prime Rib Cooking Time:

The amount of time it takes to roast prime rib in the oven is dependent on three factors: the size of the roast, its temperature going into the oven, and your desired level of doneness (i.e. rare, medium-rare, etc). 

Ideally, the roast will be at room temperature before it enters the oven. 

If this is the case, the prime rib will need 8 to 15 minutes at 500 degrees Fahrenheit, then another 1 to 2.5 hours at 300 degrees Fahrenheit, depending on the size of the roast. 11 to 14 minutes per pound for rare (120 degrees F), 15 to 18 minutes per pound for medium-rare (130 to 135 degrees F), and 18 to 21 minutes per pound for medium(138 to 140 degrees F).

So for a 5.6-pound roast to be cooked to medium, you need to first bake at 500 degrees for 8 minutes, and just under 2 hours at 300 degrees.

The bake time will need to be adjusted upward if the roast is colder than room temperature when it goes in the oven. Add another 1 minute or so to the allotted bake time if you’re cooking the prime rib fresh out of the refrigerator.

What Size Roast To Buy:

What is generally recommended is to allot 1 pound of meat per person, and/or to go by 1 rib for every two people. So if your roast is over 8 pounds and has 4 ribs, that means it will serve 8 people very comfortably.

Do take into consideration the fact that bones weigh into the weight 😉 So if you’re looking to serve, say 10 people, be sure your roast weighs 11 pounds or more.

More realistically, there will be some people who won’t eat a full pound of meat in one sitting, so judge the size you need depending on the hunger level of your guests.

Prime rib is so amazingly flavorful on its own that seasoning it with anything other than salt isn’t necessary! However, if you’re looking for some unique flavor on that crispy outer crust, here is my go-to prime rib rub:

• 2 teaspoons sea salt
• 1 teaspoon ground paprika
• 2 teaspoons Italian seasoning
• 1 teaspoon garlic powder
• 1 teaspoon onion powder.

Stir these ingredients together in a bowl, then rub them generously all over the prime rib roast as it sits at room temperature.

Difference Between Prime Rib and Ribeye Roast:

Sometimes prime rib is labeled as “Ribeye Roast” at the grocery store. After googling “difference between prime rib and ribeye” and much consternation, the answer I’m sticking with is they are basically the same thing. Both are amazing and will win you all the chef awards. Don’t overthink it. 😉 

If you’re a butcher, please fact check me, but to my knowledge, ribeye steak is simply a steak cut off of a prime rib roast (or standing rib roast as some call it). Bone-in ribeye is a steak with a rib attached to it – also cut from a prime rib roast. 

Serve this amazing main entree with your favorite side dishes. Here are some of mine.

Healthy Side Dish Recipes:

• Roasted Garlic Mashed Cauliflower
• Apple Cider Glazed Roasted Carrots with Rosemary
• Creamy Cauliflower Casserole
• Healthy Green Bean Casserole
• Shaved Brussel Sprout Salad with Roasted Butternut Squash
• Mediterranean Scalloped Potatoes

My cookbook, Paleo Power Bowls, is now available! CLICK HERE to check it out. Thank you for your support!

If you make this recipe, please feel free to share a photo and tag @The.Roasted.Root on Instagram!

Ingredients

• 1 6 to 10-lb prime rib roast
• Sea Salt

Instructions

1. Place the roast in a roasting pan (or large casserole dish) and sprinkle liberally with sea salt. Use your hands to pat the salt into the meat. If you'd like, you can refrigerate the meat for a few hours or overnight to dry brine it, but this step is not mandatory.
2. A few hours before you want to roast the prime rib, bring it to room temperature by allowing it to sit on the counter in the roasting pan. If you're in a hurry, preheat the oven to 200 degrees and allow the prime rib to sit in the oven for 10 minutes to bring the temperature up.
3. When you're ready to cook, preheat the oven to 500 degrees F.
4. Bake the roast for 8 to 15 minutes (depending on the size of the roast), until the outside is deeply golden-brown.
5. Lower the oven temperature to 300 degrees F. Bake for 11 to 14 minutes per pound for rare prime rib (or until it reaches an internal temperature of 120 to 125 degrees F), 15 to 18 minutes for medium-rare (or until it reaches an internal temperature of 130 to 135 degrees F), or 18 to 21 minutes per pound for medium (or until it reaches an internal temperature of 138 to 140 degrees F). For example, if you have a 6-pound prime rib and you want to cook it to medium, bake it for just under 2 hours.
6. Remove meat from the oven and allow it to sit 20 to 30 minutes before slicing and serving.

Nutrition Information

Yield 1 Serving Size 1 serving
Amount Per Serving Calories 580Total Fat 46gUnsaturated Fat 0gProtein 38g