Remove the ribs from the fridge half an hour before cooking and preheat the barbecue for indirect cooking.
Grind the rub ingredients to a fine dust in a pestle and mortar. Lay the ribs in a large roasting tin and coat evenly in the rub. Place the ribs on the barbecue meat-side up and cook for two hours.
After two hours
begin the mopping process. Combine all of the mop ingredients in a jug and use a large brush to generously apply the mop to the surface of both racks.
Continue cooking for a further two hours
mopping every half an hour. To test that the ribs are done
give the end of one of the racks a gentle twist; if the meat gives easily and feels tender
