The primary flavoring in balsamic vinegar is grapes. Specifically, traditional balsamic vinegar is made from freshly crushed grape must (the juice and skins of crushed grapes), which is then cooked down and fermented. The process involves aging the vinegar in wooden barrels for several years, allowing the flavors to deepen and develop complexity. The finished product is rich, sweet, and tangy, with a distinctive aroma and taste that sets it apart from other types of vinegar. Balsamic vinegar is widely used in salad dressings, marinades, and various culinary applications.