According to Royal Spanish Academy (RAE), aceto It is a term from the Latin word acētum which used to be used as a synonym for vinegar. Is named vinegar, meanwhile, to an astringent and sour substance that has at least acetic acid as one of its most important components.
Today the concept of aceto is associated with the so-called balsamic vinegar, a product originating from Modena (Italy) which, according to your Geographical Indication of Origin, must be made with juice grapes cultivated in the region. Usually, anyway, the notion is used to name liquids similar to acetate of Modena, beyond the differences of processes and composition.
The original balsamic vinegar was prepared with white grapes, which were trodden to obtain the juice. Then the liquid was reduced by placing it on fire and the wort aged for prolonged periods in different wooden barrels of different types. The qualifier of balsamic is linked to the fact that this product was considered as a balm: parents made this aceto and gave it to their daughters when they became pregnant as they believed that it contributed to the Health of the baby in formation. It was also used as an anti-inflammatory and for wound disinfection, for example.
In short, balsamic vinegar is based on the grape must. The juice of this fruit becomes vinegar although without previously transforming into alcohol since the sugar becomes directly acetic acid by the bacteria found in the kegs. In traditional vinegar, instead, the grape juice is made wine by the fermentation of sugar into alcohol.