The first part of the must is inoculated with special yeast that transforms the sugars of the grapes, first into alcohol the acetic acid. You now have wine vinegar. The second part of the must is cooked for 12 hours. The liquid becomes brown and thick. This liquid is called “cooked must” and it is put in oak barrels with the addition of a 20% wine vinegar and in three years it will become balsamic vinegar. The third part of the must is used as grape sugar.