What Is Balsamic Vinegar?

(Note:  The following is from The Sutter Buttes Olive Oil Company website.)  

Balsamic vinegar is a dark, concentrated, and intensely flavoured vinegar originating in Italy and made from grape must, the freshly crushed grape juice including the skins, seeds and stems.

The family at Sutter Buttes Olive Oil Company prepares balsamic vinegars following the traditional method:  the high-quality raw materials are mixed to obtain an elixir with a delicate perfume and balanced flavor. The only thing missing is the D.O.P. certification because it is not produced in Modena, Italy.    

Traditional Balsamic Vinegar from Modena (Taken from Serious Eats, Everything You Wanted to Know About Balsamic Vinegar.)

Traditional balsamic vinegar is labelled Aceto Balsamico Tradizionale and carries a D.O.P. ("Denominazione di Origine Protetta") stamp — an EU certification guaranteeing the vinegar's quality, production, and place of origin. The only ingredient is grape must with no additives.

Traditional balsamic is sold in wax-sealed bottles with certain identifying numbers. Traditional balsamic from Modena is only sold in a bulb-shaped 100ml bottle but if it is from Reggio Emilia it is only sold in a 100ml bottle shaped like an inverted tulip. If it is from any other location in Italy, then it cannot be called "traditional."

The History of Balsamic Vinegar: In 1046 when going to his coronation, the Holy Roman Emperor Henry III was given a silver bottle containing a celebrated vinegar, the first historical recording of its use. It was a condiment once known only to those in the Emilia-Romagna region of what is now modern Italy, and produced only in the provinces of Reggio Emilia —where Henry III was visiting —and neighboring Modena.