Technological and Microbiological Aspects of Traditional Balsamic Vinegar and Their Influence on Quality and Sensorial Properties

The term \u201cbalsamic\u201d is widespread and popular all over the world of vinegar and fancy foods; it is used generally to refer to vinegars and sauces with a sweet and sour taste. However, the original is the European Protected Denomination, registered as \u201cAceto Balsamico Tradizionale of Modena, or of Reggio Emilia\u201d that should not be confused with the \u201cAceto Balsamico di Modena\u201d very similar in the name, but completely different for technology, raw material, quality, and sensorial properties. Traditional balsamic vinegar is made by a peculiar procedure, that starts with a thermal concentration of freshly squeezed grape juice, followed by alcoholic and acetic fermentations and, finally, long aging in a wooden barrel set, by a procedure which requires a partial transfer of vinegar from cask to cask with the consequential blending of vinegars of different ages. In addition, water transfer occurs across the wood of the barrels, the result being an increase of solute concentration of the vinegar. The chemical and physical transformations of the vinegar are mainly directed by the low water activity of the vinegar. High-molecular polymeric compounds are the main and characteristic constituents of original and old traditional balsamic vinegar, and the major cause of its rheological and sensorial properties