Place the ribs in a large saucepan with the vinegar and add enough water to cover by a good 5 cm (2 inches). Bring to the boil and simmer for 20 minutes. Drain the ribs and dry on kitchen paper. Transfer to a bowl.
Meanwhile, place all the sauce ingredients in a saucepan and bring just to the boil. Simmer gently for 6—8 minutes until thickened slightly.
Brush the ribs with the marinade and, using the indirect grilling method (see