The Kosher status of such wine vinegar depends on the Kosher status of the wine used for the fermentation, and most such vinegar does not bear Kosher certification. (The H. J. Heinz Company, as well as Royal Wine Company, produces wine vinegars that are indeed Kosher approved.) Please note that wine-flavored vinegar generally refers to white vinegar that has been colored and flavored to imitate wine vinegar. Such a product may bear Kosher certification, provided that the flavorings and colorings are Kosher.