How Long to Cook a 5lb Beef Rib Roast: A Step-by-Step Guide

A beef rib roast also known as a prime rib or standing rib roast, is a gorgeous main course for holidays special events and impressive dinners. With its tenderness, marbling and full beefy flavor, it’s a cut of meat worth mastering.

But cooking the perfect beef rib roast requires more than just throwing a 5lb roast in the oven To achieve fork-tender, juicy meat encased in a flavorful, crispy brown crust, you need to know how long to cook a 5lb beef rib roast along with some key roasting techniques.

Follow this complete guide for nailing your next rib roast every time.

How Long Does it Take to Cook a 5lb Beef Rib Roast?

The basic timing guideline for roasting a rib roast in the oven is:

15-20 minutes per pound at 350°F

So for a 5lb beef rib roast, the total estimated cooking time is:

• 75-100 minutes (1 hour 15 minutes – 1 hour 40 minutes)

This roasting time is appropriate for a medium-rare rib roast. If you prefer medium or beyond, extend the time up to 25 minutes per pound.

However, roasting times are just a guideline. The shape, exact size, bone-in vs boneless and your desired doneness all impact total cook time. Relying solely on a time per pound estimate can lead to under or overcooked roasts.

Use a Meat Thermometer for Perfect Doneness

The only way to nail the ideal doneness for rib roasts is to use a meat thermometer. Insert an instant-read or oven-safe meat thermometer into the thickest part of the roast and cook until it registers:

• 120-125°F for rare
• 130-135°F for medium-rare
• 140-150°F for medium
• 160°F+ for well done

This gives you perfectly cooked rib roast regardless of variances in shape or cook time. Check temperature early and monitor it as you near estimated cook time completion.

Add Extra Time for Bone-In Rib Roasts

Bone-in beef rib roasts take longer to cook than boneless since the bone partly shields the meat. Figure on adding 5-15 extra minutes per pound for a bone-in roast.

You can remove the bone for faster cooking. But leaving it in adds flavor and gives you the dramatic presentation of a standing rib roast.

Reduce Time for Smaller Rib Roasts

Larger roasts need more time since heat takes longer to penetrate all the way to the center. Smaller 3-4lb roasts may only need 12-15 minutes per pound at 350°F.

Reduce estimated time as the size decreases but still rely on a meat thermometer for determining perfect doneness.

Allow Carryover Cooking Time

Meat temperature continues rising even after the roast is removed from the oven. Allow the beef rib roast to rest at least 15-20 minutes before carving to complete this carryover cooking.

Factor in extra oven time for pulling the roast 5-10°F below your target temperature. It will coast up to the ideal doneness as it rests.

Add Time for Low Temperature Roasting

You can slow roast rib roasts at lower 250-275°F temperatures for ultra-tender results. But the extended cooking requires added time. Figure around 25-30 minutes per pound for low roasting.

Use a meat thermometer and allow generous resting time for roasts cooked at lower oven temperatures.

Tips for Roasting 5lb Beef Rib Roasts

Follow these tips along with the timing guidelines for flawless 5lb rib roasts:

• Choose a roast with good marbling for flavor and tenderness.

• Let roast sit out for 1 hour before cooking for more even heating.

• Season well with salt, pepper and herbs like rosemary, thyme or sage.

• Sear all sides in a hot skillet before roasting to boost flavor.

• Roast fat side up on a rack in a shallow pan.

• Baste periodically with pan drippings for moisture and flavor.

• Allow at least 15 minutes resting time before carving.

With the proper roasting times and techniques, you’ll achieve the perfect medium-rare rib roast encased in a crispy, seasoned crust every time. For more rib roasting guides and recipes, check out VeryMeaty.com.