To obtain sherry vinegar (vinagre de Jerez), you adapt the approach to sherry. You combine a variety of wines, mix them in wooden kegs or barrels, and let it mature. This vinegar has Spanish origins, its producers lying within the “sherry triangle” in the Spanish province of Cádiz.
It has a lot in common with traditional Balsamic vinegar. Both must age in wood for a long time. Both must also receive the seal of approval before their producers can lay claim to it being true balsamic or sherry vinegar. Legislation dictates sherry vinegar must age in American oak for at least 6-months in the sherry triangle and be characterized by at least 7 degrees acidity. The Consejo Regulador and legislation, as well as the EU law, monitor, control and support the Denominación de Origen.
The process, the quality and quantity of sherry vinegar results in higher prices. The very best of this complex, mellow, richly flavored vinegar comes at a substantial cost.