Balsamic vinegar is a very dark, concentrated and intensely flavoured vinegar originating in Modena, Italy, made wholly or partially from grape must: freshly crushed grape juice with all the skins, seeds and stems.
The term aceto balsamico is unregulated, but there are three protected balsamic vinegars: Aceto Balsamico Tradizionale di Modena DOP (Traditional Balsamic Vinegar of Modena), Aceto Balsamico Tradizionale di Reggio Emilia DOP (Traditional Balsamic Vinegar of Reggio Emilia), and Aceto Balsamico di Modena IGP (Balsamic vinegar of Modena). The two traditional balsamic vinegars are made the same way from reduced grape must aged for several years in a series of wooden barrels, and are produced exclusively in either the province of Modena or Reggio Emilia. The names of these two vinegars are protected by the European Union's Protected designation of origin, while the usually less expensive Balsamic Vinegar of Modena (Aceto Balsamico di Modena) is made from grape must blended with wine vinegar, and produced exclusively in either Modena or Reggio Emilia, with a Protected Geographical Indication status.
Balsamic vinegar contains no balsam or balsa.