2 tablespoons sweet paprika
2 tablespoons light brown sugar
1 tablespoon table salt
2 teaspoons chili powder
1 ½ teaspoons ground black pepper
1 ½ teaspoons onion powder
1 ½ teaspoons cayenne pepper
½ teaspoon dried thyme
2 racks St. Louis-style spareribs, 2 1/2 to 3 pounds each (side ribs)
½ cup apple juice
3 tablespoons apple cider vinegar
large 9-inch aluminum pie plate
¾ cup wood chips, soaked
1. Combine rub ingredients in small bowl. Place racks on rimmed baking sheet; sprinkle rub on both sides of each rack, rubbing and pressing to adhere. Set racks aside while preparing grill. Place soaked chips in 9-inch disposable aluminum pie plate with 1/4 cup water and set on primary burner of gas grill.
2. Combine apple juice and vinegar in small bowl; set aside. Place soaked chips in 9-inch disposable aluminum pie plate with ¼ cup water and set on primary burner of gas grill. Place 9-inch disposable aluminum pie plate filled with 1 inch water on other burner(s). Position cooking grates over burners. Turn all burners to high and heat grill with lid down until very hot, about 15 minutes. Turn primary burner to medium-high and turn off other burner(s). Scrape grate clean with grill brush.
3. Place ribs, meat side down, on grate over water pan. Cover grill, positioning top vent over ribs to draw smoke through grill. Cook ribs 45 minutes, adjusting heat of primary burner to keep temperature inside grill around 250 to 275 degrees. Flip ribs meat side up, turn 180 degrees, and switch their positions so that rack that was nearer fire is on outside. Brush each rack with 2 tablespoons apple juice mixture; cover grill and cook another 45 minutes. About 30 minutes before removing ribs from grill, adjust oven rack to middle position and heat oven to 300 degrees.
4. Transfer ribs, meat side up, to wire rack set in rimmed baking sheet. Brush top of each rib with 2 tablespoons apple juice mixture. Pour 1½ cups water into bottom of baking sheet; roast 1 hour. Brush ribs with remaining apple juice mixture and continue to roast until meat is tender but not falling off bone (internal temperature should be 195 to 200 degrees), 1 to 2 hours. Transfer ribs to cutting board, tent loosely with foil, and let rest 15 minutes. Cut ribs between bones to separate and serve.