Balsamic vinegar has been produced for more than 600 years. It mainly comes from the Modena region of Italy. It takes at least 6 months to several years to produce this sweet, thick treat. Balsamic vinegar differs from other vinegar mainly in that it is produced from the juice of the grape called “must.” The grapes that are used can be one of several types, including Trebbiano, Ancellotta, Lumbrusco and Sauvignon. The true balsamic is a highly-guarded secret that very few producers share.
First, place the juice in a large pot and bring to a boil. Reduce it until it has thickened, about 30 to 70 percent or one-third of the volume. You will need enough to fill your barrel three-quarters of the way.
Transfer the reduction to the wooden barrel for aging. Be careful not to spill any; it will be hot.
Fill the wooden barrel with the juice. If you are doing this at home, you will want a small barrel that is easy to move during the aging process. The barrel should be made from ashe, oak, cherry or chestnut wood. You can find these at a brewing supply company.
Place the barrel in your attic or basement. You want a location that will be hot in the summer months and cool in the winter months. The hot temperatures help activate the fermentation process, and the cool temperatures stop it.
Allow the vinegar to age for at least 6 months before testing. Once you have completed your fist batch, try another and experiment by mixing the older batches with the newer ones.
The last step is to store in glass bottles and seal with a cork at room temperature.