Start with grape must, the freshly pressed juice of grapes
Cook the grape must slowly until it thickens and concentrates
Transfer the cooked must into wooden barrels
Age it for months or years, moving it through progressively smaller barrels
Use different woods such as oak, chestnut, cherry, mulberry, or juniper
Allow natural fermentation and oxidation during aging
Blend older and younger batches as needed
Bottle the finished balsamic vinegar when it reaches the desired flavor and thickness