Light a hardwood charcoal fire. Put the grapes on a perforated grill sheet or in a grill basket and grill over high heat, tossing sometimes, until they simply start to burst, about 6 minutes. Transfer the grapes to a plate to cool entirely.

Meanwhile, grill the orange and lemon wheels over high heat, turning once, until lightly charred, about 6 minutes. Transfer to a plate to cool entirely.

In a large pitcher, combine the wine with the easy syrup, brandy and grilled fruit and stir well. Refrigerate until the sangria is chilled and the flavors are blended, at least 1 hour and up to 8 hours. Serve the sangria over ice.