Production of the Traditional Balsamic Vinegar of Modena
According to Italian Article 4 of the April 5, 1983 Ministerial Decree, the grapes used for Aceto Balsamico Tradizionale di Modena (ABTM, or Traditional Balsamic Vinegar from Modena) must be traditional to the area. In fact, the grape that gives the best results is the local Trebbiano, though some producers favor the Lambrusco grape. The area that produces the most appreciated ABTM is the foothill of the Modenese Apennine.
There are three main factors that contribute to producing prize winning ABTM.
- Late-ripened Trebbiano grapes: Because of the high sugar concentration, these grapes produce must that, once cooked, is particularly apt for Traditional Modena Balsamic Vinegar after a minimum aging of 12 years. (25 years minimum for the ‘Extra Vecchio’ (‘Extra Old”) variety).
- The soil: The slightly calcareous soil of the area is rich in macro and micro elements that are absorbed by the vines.
- The climate: The extreme temperature range, from the hot, humid summer days to the freezing cold, winters, create the natural cycle that alternates phases of transformation (summer) with dormant periods (winter).
|The four steps: harvesting, soft crushing, cooking the must, aging|
There are four steps that must be followed though with care in order to produce prize-winning ABTM: harvesting, crushing the grapes, cooking the must, and aging.
The best grapes are selected and harvested by hand and deposited gently either in wicker baskets or a wooden crates so as not to damage the bunches before crushing. Late harvest is important because then the sugar content is high and the acidity is low. The grapes must be healthy and are chosen from vineyards grown in healthy spots. Accurate vine pruning helps produce better grapes, suitable for producing good balsamic vinegar.
The grapes are crushed either manually or with ‘soft’ crushing equipment. In the old days, when people used to crush grapes with their feet, they either used children or held onto poles in order not to crush the grapes too hard. This way, the polyphenol content would be lower, which is good since polyphenols slow down the acetification process. The juice is then filtered and decanted to clear it of all solid matter.
The filtered must is then cooked within hours of crushing to avoid alcoholic fermentation to begin with. The juice is poured into either a copper or an iron caldron and cooked without a lid for several hours, until it is reduced between 30% and 70%, depending on the quality of the must. Must with high sugar content is ideally concentrated by 50%. The process is optimized when the Babo measures between 28º and 33º.
For best results, the liquid should reach between 176º and 194º F (80º to 90º C) in about 30 minutes and kept at that level all the time, skimming the dregs that form on the surface. Higher temperature for extended time must be avoided, since the sugar could caramelize thus giving a burned taste to the final product. The cooked must is then cooled down naturally in either wood or iron vats, before being stored in demijohns for several months to decant.
Aging is arguably the most delicate and ‘personal’ phase, when the choices made by the producer affect the finished product without altering the overall quality. It is important to follow a few rules scrupulously which producers often transmit orally from generation to generation.
An acetaia is composed of wooden barrels of various sizes called vaselli.
Refilling the vaselli
Each year, in the fall, the smaller barrel content is refilled up to two third of its capacity with from the bigger barrel immediately preceding it within the same batteria , that barrel is then refilled from the bigger one, and so on up to the first barrel. The biggest barrel in each batteria is then refilled by adding new cooked must after decanting in demijohns from the previous fall. From this moment on, time plays the most important role: the changes in the smaller vaselli happen very slowly, refining the characteristics of the finished product. With age, the ABTM acquire balance and roundness of taste, increasing the sugar residues and maintaining constant acidity.
Between the end of October and the end of March the fermentation is suspended, thus this is the ideal period for the yearly refilling. It is important to keep under control the state of the barrels’ contents. The olfactory and visual analysis are made through the cocchiume, that is, the rectangular hole at the top of the vasello. The taste analysis is made using a long glass tube to withdraw a small quantity of liquid for sampling.
It is advisable to cover the cocchiume with a piece of cloth or thick gauze. In the old days, the hole was covered with a stone from Panaro, the local river. The stone was corroded by the exhalations of the vinegar and would deposit small pieces of limestone that would help keep the acid level low.