The Olive Cellar Balsamic Vinegars are made from a white Tebbiano or Lambrusco grape must, which is the freshly pressed fruit juice that contains the skins, seeds, and stems of the grapes. Our dark and white Balsamic Vinegars are of the highest quality and are made in Modena, Italy from only these grapes. We refer to our dark balsamic as, “Traditional Style Condimento, Aged up to 18 years.” The grape must is cooked over an open wood fire and is cooked down to the same consistency, density and dry solid extracts. The wood-fire-cooked grape must is then put directly into aged, fired wood barrels. The barrels as well as the product they once contained, add character and complexity in flavor to the must. The probiotics wild yeast and acetic bacteria colonize it and eventually raise the acidity. It slowly ages in this manner and turns into “vinegar” over the up to 18 year aging process. By Italian law, it must then be tested for quality by measuring many specific criteria, such as, the dry extract solids. Our condimento’s very low acidity of 4.5% is a function of the grape must being naturally cooked down, condensed and aged without the addition of thickeners and sweeteners. All of our vinegars are Non-GMO Project Verified.