How is vinegar made?
Vinegar’s closest relative is wine; it’s the natural conclusion of the winemaking process. By exposing wine to oxygen, naturally occurring bacteria in the air convert the alcohol into water and acetic acid. From there the hand of the vinegar maker takes over.
Great vinegar takes lots of care and time to create.
But, in the case of large industrial vinegar producers, time is something they can’t afford. In order to maximize profits they’ve developed ways to shorten the process of vinegar making from months and years to days and hours. Chemicals like sulfuric acid, nitric acid, and muriatic acid are added to give it “strength.” Burnt sugar and acetic ether (a colorless, flammable liquid with a fruity flavor) are added to give it color and flavor. Even if you didn’t major in chemistry you can probably recognize that these are some caustic chemicals.
Traditionally made vinegars have none of that nonsense. They take a long time to mature and can’t compete on price with the industrial models. Great vinegar transforms and accentuates the flavors of dishes; the cheap stuff can mar a meal. The amount of flavor in one bottle of well-made vinegar is magnitudes better than the cheap, commercial stuff.
The Orleans Process
Orleans is probably the oldest method of making vinegar – at least as old as wine itself. Barrels are partially – but never fully – filled with wine, allowing air to interact with the liquid. Bacteria, often left over from the previous vinegar, naturally converts the alcohol into vinegar. Better vinegars age in wood for a long time, the wood and evaporation adding to their flavor. Sherry vinegar gets a special barrel treatment, with different ages of vinegar mingled in a battery of barrels called a solera, sometimes for decades.
The Balsamic Process
Grape must – the juice before it’s wine – is cooked down to half its original volume then stored in large wooden casks that are exposed to air. After a year or so the young vinegar is blended into older, smaller barrels that hold more “experienced” balsamic. The older vinegar “teaches” the younger and the characteristics of both are merged. After more aging, some of the vinegar is removed and blended with different barrels holding different ages and the process continues, sometimes for generations.