Blackberry-Ginger Balsamic Glazed Wings

Combine soy sauce, balsamic, pepper, olive oil, and wings in a large, zip-top bag. Close bag and refrigerate for 4 hours to overnight. Preheat an outdoor grill to medium heat. Remove the chicken wings from the marinade and pat dry. Cook the wings on the preheated grill, turning occasionally, until the chicken is well browned and no longer pink, 25 to 30 minutes. Place the reserved marinade in a small saucepot set over medium-low heat, and gently simmer until reduced by half, approximately 5 minutes. Place grilled wings in a large bowl. Drizzle with reduced balsamic marinade and toss to coat well.