Grilled Spareribs with Cherry Cola Glaze

4 (12 ounce) cans cherry cola (flat)
2 cups cherry jam or preserves
2/3 cup Dijon mustard with horseradish
3 tablespoons soy sauce
2 tablespoons malt vinegar or apple cider vinegar
1 tablespoon hot pepper sauce
7 to 7 1/2 pounds well-trimmed pork spareribs

Boil cherry cola in heavy large saucepan over medium-high heat until reduced to 1 1/2 cups, about 45 minutes.

Stir in next 5 ingredients. Reduce heat to medium and simmer until mixture is reduced to 2 1/2 cups, stirring occasionally, about 35 minutes.

Transfer glaze to large bowl. Position racks in top and bottom thirds of oven and preheat to 325 degrees F.

Sprinkle ribs with salt and pepper. Wrap each rib rack tightly in aluminum foil, enclosing completely.

Divide foil packets between 2 rimmed baking sheets. Bake until ribs are very tender, switching positions of baking sheets halfway through baking, about 2 hours total. Cool ribs slightly in foil. Pour off any fat from foil packets.

Prepare barbecue (medium-low heat).

Cut each rib rack between bones into individual ribs. Set aside 1 cup glaze. Add ribs to bowl with remaining glaze and toss to coat. Grill ribs until brown and glazed, turning to prevent burning, about 5 minutes total.

Serve, passing reserved glaze separately.