Use the grill to roast a prime rib for flavour and texture

By America’S Test Kitchen The Associated Press

If you’re going to grill a prime rib, the last thing you want is an overcooked grey ring surrounding the rosy interior. We decided to forgo searing the flat cut sides, which meant the roast spent less time over high heat.
The reduced amount of searing time was enough to create a browned crust, but not enough to start overcooking the meat. The other problem we encountered was persistent flare-ups from the fat that dripped down through the grate. To minimize this, we had the butcher trim the fat to a mere 1/8-inch thickness.
Although we liked the idea of a boneless roast for easy carving, we knew that the bones would protect the underside of the meat from overbrowning. We bought our prime rib bone-in, removed the bones ourselves and then secured the detached bones onto the roast just for the grill.
Using a grill to roast a prime rib gave us the advantage of being able to create both flavour and texture contrast between the exterior and interior. A garlic-rosemary paste, brushed on after browning, gave the crunchy crust extra flavour. Wood chips, though a nontraditional addition, gave the outer 1/2 inch of the roast a subtly smoky flavour, further heightening the contrast between layers.
Usually, when we think of grilling, we think of steaks and ribs. In this recipe, we wanted to harness the smoky environment of the grill for a different purpose: to cook prime rib. But to ensure that this premium cut got the treatment it deserved, we needed to perfect the method.
Servings: 6-8
Start to finish: 6 1/2 hours
First-cut beef rib roast is also known as prime rib, loin end, or small end. If your butcher doesn’t trim excess fat from the roast and remove the bones (which you need for this recipe), see below for information on removing the bones. If all you have is a boneless roast, see our tip at right for making a false bone. If you’d like to use wood chunks instead of wood chips when using a charcoal grill, substitute 2 medium wood chunks, soaked in water for 1 hour, for the wood chip packet.
1 (7-pound) first-cut beef standing rib roast (3 or 4 bones), meat removed from bones, bones reserved, exterior fat trimmed to 1/8 inch
1 tablespoon vegetable oil
Kosher salt and pepper
2 cups wood chips
1 (16 by 12-inch) disposable aluminum roasting pan (if using charcoal)
Cutting the meat off the bone with prime rib:If your butcher doesn’t remove the bones from the prime rib for you, here’s how you can do it yourself: Holding meaty lobe in one hand and sharp boning or chef’s knife in your other hand, run knife down length of first bone, following contours as closely as possible, to separate it from meat.
Flip roast so uncut portion faces you. Holding bones back with your hand, cut meat from remaining ribs. Once meat is removed, proceed with seasoning and tying as directed in recipe.
Pat roast dry with paper towels, rub with oil, and season with pepper. Spread 1/4 cup salt on rimmed baking sheet and press roast into salt to coat evenly on all sides. Place meat back on ribs so bones fit exactly where they were cut; tie meat to bones with 2 lengths of kitchen twine. Refrigerate roast, uncovered, for 1 hour, then let sit at room temperature for 2 hours.
Just before grilling, soak wood chips in water for 15 minutes, then drain. Using large piece of heavy-duty aluminum foil, wrap soaked chips in foil packet and cut several vent holes in top.
For a charcoal grill: Open bottom vent halfway and place disposable pan on 1 side of grill. Light large chimney starter two-thirds filled with charcoal briquettes (4 quarts). When top coals are partially covered with ash, pour evenly over other half of grill (opposite disposable pan). Set cooking grate in place, cover, and open lid vent halfway. Heat grill until hot, about 5 minutes.
For a gas grill: Turn all burners to high, cover, and heat grill until hot, about 15 minutes. Turn primary burner to medium and turn off other burner(s). (Adjust primary burner as needed to maintain grill temperature of about 325 F.)
Clean and oil cooking grate. Place roast on hotter side of grill and cook (covered if using gas) until well browned on all sides, 10 to 15 minutes, turning as needed. (If flare-ups occur, move roast to cooler side of grill until flames die down.)
Transfer roast to second rimmed baking sheet. If using charcoal, remove cooking grate and place wood chip packet on pile of coals; set cooking grate in place. If using gas, place wood chip packet directly on primary burner. Place roast on cooler side of grill, bone side down, with tips of bones pointed away from fire. Cover (position lid vent over meat if using charcoal) and cook until meat registers 115 F to 120 F (for rare) or 120 F to 125 F (for medium-rare), 2 to 2 1/2 hours.
Transfer roast to carving board, tent loosely with aluminum foil, and let rest for 20 minutes. Remove twine and bones, slice meat into 1/2-inch-thick slices, and serve.