Combine all ingredients in a medium saucepan over medium heat. Bring sauce to a boil, then reduce heat to low and simmer for 15 minutes. Remove from heat and let cool. (Yields 1 and 1/2 cups)

Combine salt, pepper, and garlic powder. In a large bowl, toss wings with seasoning until evenly coated.

Preheat a gas grill to medium heat (about 350 degrees Fahrenheit).

Place wings on the grill, crowding them together so that they are all touching. (This helps create steam to keep them moist and not dry out on the grill.) Grill over low heat, flipping wings every five minutes, for a total of 20 minutes. Use a pastry brush to brush wings with sauce, then cook for another five minutes, until browned and cooked through.

Serve with additional sauce on the side.