Traditional balsamic vinegar may be labeled as “Aceto Balsamico Tradizionale di Reggio Emilia” or “Aceto Balsamico Tradizionale di Modena.” Vinegar labeled with these names must be produced in either the regions of Modena or Reggio Emilia, Italy. The process by which these traditional vinegar are made takes years and produces an incredibly thick, glossy, flavorful product. Only Trebbiano or Lambrusco grapes are used to make this type of balsamic vinegar. The juice from these grapes is aged in wooden barrels for 12 to 18 years to develop its unique flavor. Traditional balsamic vinegar is the highest grade available and carries the largest price tag.