Pickling spice is a blend of various spices and herbs used to flavor pickled foods. Common ingredients include mustard seeds, coriander seeds, dill seeds, black peppercorns, and bay leaves. This mixture enhances the taste of vegetables, fruits, and even meats during the pickling process. Typically, pickling spice is added to vinegar brines, which help preserve the food while imparting a tangy flavor. The specific combination of spices can vary by recipe or regional tradition, allowing for a wide range of flavors in pickled products.