The process of making Traditional Balsamic Vinegar has been kept somewhat secret, but slowly we are discovering how this prized vinegar is produced. The tradition originated in the region of Modena and was shortly adopted in the Reggio Emilia region. It is made from Trebbiano grapes in most cases, but sometimes, depending on the particular producer, Lambrusca grapes are added as well. Both of these types of white grapes are usually poor for making wine, so the Italians found another use for them in balsamic vinegar. The grapes are harvested late in the season to give them enough time to naturally produce a high amount of sugar. The freshly harvested grapes are processed into a must, or grape juice, by de-stemming them and crushing the grapes to release the juice and sugars. Once the skins and pulp have been filtered out, the must is slowly cooked down in copper vats over low heat for anywhere from twelve hours to over a day depending on the size of the batch. The must is concentrated to about half of its original volume and then is ready to begin the process of fermentation, acetification and aging.
The method of aging is called “a Solera,” in which the balsamic product is moved from a large barrel and into smaller and smaller barrels after a designated amount of time. This same process is also sometimes used in the aging of beer, wine, and spirits. The balsamic is given room to “breathe” and evaporate out of the barrel unlike the aging of alcohol which is done in a sealed barrel. This process concentrates the flavors and makes the balsamic very viscous while allowing the microorganisms necessary to convert the grape must into vinegar to enter the barrels. Each barrel is made of different wood and each imparts a flavor different from the last, making the balsamic more complex with each barrel it enters and exits.
There are seven types of approved wood that are used in the traditional process: oak, cherry, juniper, mulberry, chestnut, acacia, and ash. The individual producer can choose any combination of wood for the series of barrels depending on preference and the flavors and aromas they wish to acquire. The time in each barrel differs depending on the individual producer and their specific method.
They start by placing the must into a large barrel, usually around fifty gallons. Then, every couple of years (or more in some cases), the balsamic is moved into a smaller barrel. This process continues through several barrels until it reaches a barrel of just a gallon or two. This can take anywhere from 12, 25, 50, or even 100 years depending on the quality and taste the producer desires. Generally the longer the aging time, the better (and more expensive) the end product is.
Traditionally, the process was carried out in an attic because there was room to store the collection of barrels needed for balsamic vinegar. Most producers follow this tradition of storing the barrels in the attic so the balsamic is influenced by the seasonal weather changes. It is thought that the extremes of cold in winter and hot in summer add to the complexity of the flavor. In the summer the heat is ideal for the microorganisms to spawn and convert the sugars to acid, and it helps the product breathe. When the cold of winter hits, the acetification and evaporation slows and the balsamic is given a chance to collect the flavors from the different wooden barrels.
There are approximately 100 families that are licensed to make this illustrious product and true Traditional Balsamic Vinegar can only be labeled as such after it has passed a rigorous test by a panel from the Consortium of Balsamic Vinegar. The council was set up in the 1970’s to keep imitators from trying to sell the commercial grade as authentic balsamic. They actually created a law forbidding impersonators to label their product as Traditional Balsamic Vinegar. The producer must keep track of everything involved in the process from the grape growing, harvesting, loading and unloading of grapes, and all of the details about the aging process. The council will then take a small amount from a producer’s batch and follow the exact method of testing put forth by the council. They test every quality from the viscosity and color to the taste and smell of the precious vinegar. If it passes all categories by all five judges then it can be labeled as Traditional Balsamic Vinegar. There is also a certain method of labeling and even a specific bottle that has to be used, one for the region of Modena and one for the region of Reggio Emilia.