Light a grill. In a bowl, whisk together all the ingredients except the corn. Generously brush the sauce all over the ears. Grill the corn over a low fire for 8 to 10 minutes, turning and brushing with the sauce, until tender and lightly charred. Transfer the ears to a platter, brush with any remaining sauce and serve.
The barbecue sauce can be refrigerated for up to 2 days.