True balsamic vinegar is made of one thing: cooked grape juice.
But, it takes a minimum of 12 years, and lots of love, to transform ordinary juice into delicious balsamic vinegar.
Labrussco grapes are used for the juice. Lambrusco is a grape native only to this region of Italy.
It is then poured into a battery of wooden barrels. There are 5 barrels of 5 different woods, and 5 different sizes. (The wood types include: oak, juniper, cherry, and other local woods.)
To prepare new barrels takes at least 2 days. They need to be thoroughly cleaned with soap, salt, and lots of warm water to remove all the tannins from the wood.
Then, after the grape juice has been cooked for 24 hours, it can be poured into the battery, filling each of the 5 barrels to the top.
The barrels are then left uncovered during the summer. They need hot summers and cold winters to become vinegar.
After an entire summer of resting, about ¼ of the volume of each barrel would have evaporated, concentrating the flavor.
During the cold winter, the vinegar can be moved from one barrel to the other. The smallest barrel is filled from the next smallest, and so on. This evenly distributes the flavors of each wood into the balsamic.
It takes 12 years to transform 100,000 liters of grape juice into just 10 liters of balsamic vinegar.
Not all vinegar is made from a blend of woods.
Sometimes a maker will make a reserve – a vinegar aged in only one type of wood. We were able to taste a reserve from juniper wood, and one from cherry. It was amazing to taste the difference!