Preheat an indirect BBQ to 275˚F (use fruitwoods if possible, such as apple).
Spread ribs evenly with Spice Paste.
Place the ribs in the cooker and cook indirect (meaning not in direct exposure to fire) for 2 hours.
While ribs are cooking, combine the fortified barbeque sauce in a bowl and set aside.
When the 2 hours has elapsed, tear off 4 large sheets of aluminum foil (enough to accommodate two racks of ribs side by side). On first sheet, place half of the packet mixture on the foil, top with a rack of ribs meaty side down, and wrap in the foil, crimping to seal securely. Wrap with the second sheet of foil. Repeat for the remaining 2 racks of ribs.
Place the wrapped ribs back in the cooker, and cook for an additional hour.