Prepare the marinade by gently boiling the first 6 ingredients, in a medium saucepan, until reduced and thick; about 20 minutes.
Remove from heat and allow to cool completely.
Divide into two containers and refrigerate one container for later.
Place ribs on a large baking sheet lined with heavy foil.
Brush half the marinade all over the ribs, ensuring both sides are completely covered.
Cover with foil and refrigerate for 8 hours to marinate.
When you're ready to cook the ribs, pre-heat the oven to 275°F.
Place the pan, still covered in foil, into the oven for 2 hours.
Remove from the oven, remove the foil and increase the temperature to 300°F.
Using the other half of the sauce, brush another generous layer all over the ribs.
Return the pan to the oven and continue cooking for another 30 to 40 minutes, brushing on another layer of sauce as it cooks.
Remove the ribs when they're fork tender; some ovens may require more than the 30 to 40 minutes to reach the fork tender stage.
Slice and serve.
