Preheat an indirect BBQ to 275F (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.
Remove the wrapped ribs from the cooker and carefully remove from foil packets.
Coat with fortified BBQ sauce. Place back in the BBQ meat side down for 15 minutes, flip over, brush with additional sauce then continue to cook for an additional 15 minutes.
Remove ribs to cutting board. Cut the ribs from the racks and brush the exposed sides with the remaining barbeque sauce.