According to the Hearth, Patio and Barbecue Association, manufacturers shipped more than 15 million outdoor grills to stores for purchase in North America in 2010. Businessman and former boxer George Foreman had sold an additional 100 million indoor grills worldwide as of 2010. Ribs remain a grilling favorite. Using foil and medium heat when you grill them is the secret to moist, tender ribs.
Warm up your grill to medium heat. If you use an outdoor charcoal grill and can't set the temperature to medium, hold your hand over the center of the coals, palm down. You’ve achieved medium heat if your hand begins to feel uncomfortably warm in about 6 to 8 seconds. Don’t test until all the flames have died down.
Apply your rub to your ribs, either your own recipe or a commercial product. Towel dry the ribs first to remove all excess moisture and make sure the rub covers them evenly.
Place two sheets of heavy-duty foil wrap on a flat surface, one on top of the other. Place no more than two racks of ribs on the foil, side-by-side in the center; if you're making more than two racks, repeat the process. Place an ice cube under each rack and bring the edges of the foil up to cover the ribs entirely. Seal the foil tightly so steam can’t escape during grilling. If your ice cubes are small, you can use two, one placed at each side of the rack.
Place the ribs, in the foil, on the center of your grill. Close the lid and cook them for 1 hour. If you are cooking two foil packets, you may need to give your ribs a little more time. An outdoor grill is preferable, unless your indoor grill is large enough that you can close the lid securely over the rib packets and trap the heat.
Remove the ribs from the grill, place them on a work surface and cut a small slit in the top of the foil. Step back when you do this because a sudden puff of steam will escape. When the steam is gone, remove the ribs from the foil and return them to the grill. Baste them with your favorite barbecue sauce and grill them for an additional 7 to 10 minutes. Turn them once to baste them on both sides.
Test for doneness. When your ribs are ready, a toothpick should penetrate easily between the bones.