This closed-oven method will give you a beautifully crusted boneless rib roast that’s cooked to a perfect medium rare using the prime rib 500 rule. This technique is ideal for smaller, 4 to 7 pound boneless rib roasts. Learn how to make this easy and delicious roast for your Christmas or holiday gathering!
Rib roasts with au jus are usually saved for special occasions in our house, and of course, we need them to be cooked perfectly! This closed-door prime rib method initially “sears” the roast at a high heat of 500 degrees Fahrenheit, helping it develop an impressive crust, then cooks the roast using the residual heat from the oven until it reaches medium rare.
My husband has been cooking our prime rib with this method for quite some time now, and it’s delivered the perfect roast each time. Read below on the specifics of getting this amazing restaurant-quality roast!
Jump to:
- What is the Prime Rib 500 Rule?
- This closed oven method is recommended for
- How to calculate the Prime rib 500 F rule
- Can I use this method if the roast is bigger than 7 pounds?
- Ingredients & Equipment Notes
- Instructions
- Pro Tips
- How to avoid an undercooked rib roast
- What to do if the roast is too rare?
- Frequently Asked Questions
- More Holiday recipes to try
- Cooking a Small Prime Rib Roast with the Prime Rib 500 Rule
What is the Prime Rib 500 Rule?
This is a simple formula used to cook a perfect medium rare prime rib roast with the closed oven method.
This closed oven method is recommended for
- Small, boneless rib roasts between 4 to 7 pounds. I have found that cooking bone in rib roast with this method does not work as well as the meat near the bone comes out too rare for my liking.
- Medium rare roasts - If you like medium or well-cooked meat, this method is not for you.
- Ovens with NO cooling fans - this is very important. If your oven has an internal cooling fan, it will make the oven lose heat too fast and won’t roast the meat appropriately. If you want to try this method and your oven has a cooling fan, here are some options:
Option 1: You can try to turn the power breaker to the oven OFF.
Option 2: Don't turn off the oven after you complete the active roasting time, just set your oven to the lowest the possible temperature for the following two hours.
How to calculate the Prime rib 500 F rule
To determine the “active” roasting time (how long you'll roast the meat at 500 degrees Fahrenheit) multiply the weight (in pounds) of your roast by 5 minutes.
If your roast is 4 pounds, then 4 X 5 = 20 minutes of “active” roasting time. If roast is 4.5 pounds, then 4.5 x 5 = 22.5 minutes roasting time (I would round up to 23 minutes).
Here is an easy chart for reference!
*For half pound calculations, cooking time is rounded up.
Can I use this method if the roast is bigger than 7 pounds?
Your roast should be boneless and if it is more than 7 lbs, then I recommend cutting the roast evenly in half. Calculate the roasting time based on one rib roast.
Ingredients & Equipment Notes
Boneless Rib Roast - I am using a 4 pound roast.
Coarse Kosher Salt & Cracked Pepper - Use coarse salt as it provides a nice crust. Table salt is too fine, and will make the roast too salty.
Baking Rack - We are using a boneless roast, so a baking rack is highly recommended to get a nice crust on the bottom of the roast.
Timer - You'll need to keep a close eye on the roasting time!
Kitchen twine - You'll need this to tie the roast into a uniform size.
Instructions
1). Set the roast out at room temperature at least 3 hours prior to roasting. 30 minutes prior to roasting, Preheat the oven to 500 degrees. Your oven will probably reach 500 degrees before 30 minutes, but don’t stick the roast in yet, you want to make sure the oven is as hot as possible. Generously season the roast with salt and pepper.
2). Make sure to season all sides!
3). Tie the roast with twine, making sure it’s a uniform circumference.
4). Place the roast on a baking rack set in a roasting pan, fat side up. Place the roast in the oven on the middle rack. Shut the door and set your timer for the active roasting time.
When the timer goes off, turn off the oven, then set your timer for 2 hours and walk away! Put a huge DO NOT OPEN sticky note or a sign next to your oven! DO NOT open the oven door until the timer goes off!
Once the 2 hours is up, cut and serve right away with some au jus sauce and horseradish!
Pro Tips
- Make sure your roast is close to room temperature prior to cooking. A cold roast will cook unevenly and result in rare meat.
- Use a kitchen scale to measure the boneless rib roast to ensure your prime rib is cooked to a perfectly medium rare.
- Tying the roast helps it cook more evenly, and you'll get nice, round pieces when you slice it. One end of the roast may be smaller than the other, so ensure you tie it to make the circumference as uniform as possible.
- There’s no need to rest the meat. The resting period occurs when the oven is cooling off.
- This recipe will not yield any pan drippings.
- Your kitchen might smoke up! Make sure the windows are open and fans are running or your smoke alarm will go off!
How to avoid an undercooked rib roast
Use an Instant-read thermometer for more accurate reading. Insert it into the deepest part of the meat to check the internal temperature of the roast.
For reference:
- Rare: 120°F
- Medium-rare: 130°F
- Medium: 140°F
- Medium-well: 150°F
- Well-done: 160°F
What to do if the roast is too rare?
If the roast is too rare for your liking, or if others prefer a more well done portion, here are some options to remedy it.
Option 1:
Put the Whole Roast Back in the Oven: If the entire roast is undercooked, place it back into the oven at 300°F. Cook for 10-minute intervals, checking the internal temperature frequently until it reaches the desired doneness.
Option 2: Slice and recook.
If you have to serve the meat right away, slice the roast into individual portions and finish cooking it in the oven. Recook it at 350°F in the oven for about 10 minutes, or until it reaches the desired doneness. The thickness of the slice is determined by how soon you have to serve. Thinner slices cook quicker.
Option 3: Quick Sear
This is recommended for guests that like their portion medium-well to well done.
Heat a skillet/pan with some oil or butter on medium high heat. Then add the individual sliced meat onto the hot skillet and sear for about 1 to 2 minutes on each side or until cooked to desired doneness.
Option 4: Reheat in sauce
Heat some au jus or gravy in a pan, when hot, add a slice of meat to the sauce and cook quickly for 30 seconds or until desired doneness.
Frequently Asked Questions
For this closed oven method, you cook it uncovered because you want a nice crispy brown crust.
Slice the roast and serve it with traditional sides like mashed potatoes, corn, asparagus and rolls.
How thick should you slice prime rib?
Prime rib roast should be cut into ½ - ¾“ slices.
Cook fat side up so the fat will render and add flavor to the rest of the roast.
More Holiday recipes to try
Love a recipe you've tried? Please leave a 5-star 🌟rating in the recipe card and a comment below! That'll make my day!
Let's be friends! Follow me on social media @ Instagram, Pinterest. Give me a tag @apeachyplate when you try out a recipe!
Cooking a Small Prime Rib Roast with the Prime Rib 500 Rule
Ingredients
- 4 pound Boneless rib roast
- Kosher salt, to taste
- Cracked pepper, to taste
Instructions
- Set the roast out at room temperature 3 hours prior to roasting.
- 30 minutes prior to roasting, Preheat the oven to 500 degrees.
- To determine the “active” roasting time (how long to roast the meat at 500 degrees Fahrenheit) multiply the weight (in pounds) of your roast by 5 minutes. Example: If your roast is 4 pounds, then 4 X 5 = 20 minutes of “active” roasting time. If roast is 4.5 pounds, then 4.5 x 5 = 22.5 minutes roasting time (I would round up to 23 minutes).
- Tie the roast with twine, making sure it’s a uniform circumference.
- Generously season all sides of the roast with kosher salt and pepper.
- Place the roast on the roasting pan with a rack, fat side up. After 30 minutes of preheating the oven, place the pan on the middle rack. Shut the door and set your time for the active roasting time. Set a timer!
- When the timer goes off, turn off the oven. Set your timer for 2 hours and walk away! Do NOT open the oven door!
- Once the 2 hours is up, cut and serve right away.
Notes
- This closed oven method is recommended for:
- Small boneless rib roasts between 4 to 7 pounds.
- Ovens with NO cooling fans - this is very important. If your oven has an internal cooling fan, it will quickly reduce the temperature inside the oven, decreasing the active roasting period.
- For medium rare roasts
- Make sure your roast is at room temperature prior to cooking. A cold roast will cook unevenly and result in rare meat.
- There’s no need to rest the meat. The resting period occurs when the oven is cooling off.
- Use the meat thermometer by inserting it into the deepest part of the meat. For medium rare the temperature should read 125 - 130 degrees Fahrenheit.
- This recipe will not yield any pan drippings.
Tandra Castro
I read instructions but do you cover roast or leave it open/uncovered while roasting at 500 ? Thank you
Kaylie
uncovered
Jodi Ann Kubek
Exactly what I was looking for and needed for this years Christmas dinner.
Kaydi
I love this recipe the closed oven method is the best way to cook a prime rib roast comes out perfect every time