Prime Rib Roast Recipe Temp: Perfect Medium Rare With Reverse Sear

Mastering prime rib requires precision, but the reverse sear method guarantees perfect results every time. This technique transforms a simple roast into a showstopping centerpiece with ideal medium-rare doneness throughout.

I developed this approach after years of trial and error, learning that low-and-slow oven cooking followed by a high-heat sear delivers unmatched tenderness. The temperature control is what sets this apart from traditional methods.

The reverse sear creates an even cook from edge to edge, with a crusty exterior that locks in juices. No more overcooked ends or underdone centers—just consistent, restaurant-quality prime rib.

Serve this to impressed guests who will swear it came from a steakhouse. Here’s how to achieve that perfect medium-rare finish.

Ingredients for Prime Rib Roast Recipe Temp

Eleven ingredients transform a premium cut into that showstopping centerpiece with edge-to-edge perfection.

The beef is non-negotiable here. USDA Prime grade from a reputable butcher like Whole Foods or Local Harvest delivers the marbling you need. Ask for the ribeye end—it’s more flavorful. If prime isn’t available, Choice grade works but trim excess fat. Bone-in roasts cook more evenly and add depth. Always let it rest at room temp for 2 hours before cooking (don’t skip this).

No beef stock? Low-sodium chicken broth works in a pinch, but beef is ideal. Short on herbs? Dried at one-third the amount, but fresh rosemary and thyme are worth hunting down—they infuse beautifully. Skip the wine? Extra beef stock plus a splash of balsamic mimics the depth. The Dijon mustard is for the crust, so don’t substitute yellow mustard (too mild).

Prime rib reheats surprisingly well. Slice first, then warm in beef stock at 325°F for 10-15 minutes. Keeps in the fridge for 4-5 days, freezes beautifully for 3 months. Always carve against the grain for maximum tenderness.

Step-by-Step Instructions for Prime Rib Roast

This reverse sear method guarantees a stunning medium-rare result with minimum stress.

Step 1: Season and Prep the Prime Rib Roast

Pat the 5 lb Prime Rib Roast dry with paper towels to ensure a perfect crust. I always remove it from the refrigerator 2 hours before cooking to bring it to room temperature—this promotes even cooking throughout.

Rub the roast all over with the 0.25 cup Extra-Virgin Olive Oil, then season aggressively with the 2 tbsp Kosher Salt and 2 tsp Freshly Ground Black Pepper. The seasoning should form a visible crust on the surface. This is your flavor foundation.

Make small slits in the fat cap and insert the 6 cloves Garlic Cloves, 4 whole Fresh Rosemary Sprigs, and 4 whole Fresh Thyme Sprigs to infuse the meat with aromatic depth as it cooks.

Step 2: Slow Roast in a Low Oven

Preheat your oven to 250°F—this low temperature is key to achieving edge-to-edge medium-rare perfection. Place the roast fat-side up on a rack in a roasting pan. The rack elevates the meat, allowing hot air to circulate for even cooking.

Insert a meat thermometer into the thickest part of the roast, avoiding the bone. Roast until the internal temperature reaches 115-120°F for medium-rare, which typically takes 2 to 2.5 hours for a 5 lb Prime Rib Roast. This slow cook ensures the center comes up to temperature without overcooking the outer layers.

Step 3: Create a Crust with High-Heat Sear

Remove the roast from the oven and increase the temperature to 500°F. While waiting, brush the roast all over with the 2 tbsp Dijon Mustard—this adds a tangy depth to the crust and helps it brown beautifully.

Once the oven reaches temperature, return the roast to the oven for 10-15 minutes to develop a deep, caramelized crust. Watch closely—you want the exterior to turn a rich dark brown but not burn. The internal temperature will rise to about 130°F, perfect for medium-rare.

Step 4: Rest and Prepare the Pan Sauce

Transfer the roast to a cutting board and tent loosely with foil. Let it rest for 20-30 minutes—this allows the juices to redistribute for maximum tenderness. Meanwhile, place the roasting pan on the stovetop over medium-high heat.

Add the 0.5 cup Red Wine to the pan and deglaze, scraping up all the browned bits. Let it reduce by half, then add the 1 cup Beef Stock and 4 tbsp Unsalted Butter. Simmer for 5 minutes until slightly thickened. Strain and serve alongside the roast.

Step 5: Slice and Serve with Horse Radish

Carve the roast into thick slices, cutting between the bones for elegant presentation. Serve immediately with the pan sauce and a dollop of the 0.25 cup Horse Radish on the side. The contrast of the creamy horse radish with the rich beef is incredible.

Pro Cooking Tips for Perfect Results

Perfect Temperature Control

I swear by my ThermoWorks Smoke thermometer for tracking both oven and internal temps. The probe in the thickest part (avoiding bone) gives accurate readings. Aim for 250°F oven temp during the slow roast phase—this is non-negotiable for even cooking. 🌡️

Reverse Sear Timing

For a 5 lb roast, expect 2-2.5 hours at 250°F to hit 115-120°F internal. I learned the hard way that rushing this phase creates uneven doneness. The meat will continue cooking during the sear, so don’t pull it too early.

Crust Development

After removing the roast, crank the oven to 500°F. Brush with 2 tbsp Dijon Mustard before returning it for the final sear. This step takes 10-15 minutes—watch for that perfect dark brown crust without burning.

Resting is Crucial

Let it rest 20-30 minutes under foil before slicing. I use this time to make the pan sauce—it’s the perfect window. Skipping this step means losing precious juices to your cutting board. 💡

Carving Technique

Slice between the bones for beautiful presentation. I use a Wüsthof 12-inch carving knife from our wedding registry. Always cut against the grain for maximum tenderness—this makes every bite melt in your mouth.

Pan Sauce Pro Tip

Deglaze with ½ cup dry red wine first, then add 1 cup beef stock and 4 tbsp butter. Simmer for 5 minutes until slightly thickened. Strain before serving—I learned this from a Portland chef at a cooking class.

Frequently Asked Questions