Start With High Sugar Content Grapes :
Balsamic vinegar is an aged reduction of white and red sweet grapes that are boiled to a syrup (called cooked must) and then aged for 12 years or longer using the solera system. This involves transferring the vinegar along a line of barrels of decreasing size each year. In the case of Balsamic Vinegar, the barrels are made of different woods.
- As with most vinegar, true Aceto Balsamico starts out as must (unfermented juice). Unique from other vinegars, local sweet white and red grapes with a high sugar conten Lambrusco, Trebbiano and often other varietals like Spergola, used in small quantities. The grapes are grown on the hillsides surrounding Modena, are harvested as late as possible, and often left in the sun for further ripening to increase the sugar level.
- The grapes are then crushed and pressed, and the must is allowed to sit until fermentation is about to begin. Thus, unlike other vinegars, balsamic does not come from wine, but from grape juice that has never been allowed to ferment into wine.
- At the very start of fermentation, the must is filtered and poured into large, open copper cauldrons.
- The must is brought to a boil and slowly simmered over a wood fire. It is cooked until the water content is reduced by an average of one-half. This takes from 13 to 16 hours.
- The must is then cooled, allowed to settle and combined with an older Balsamic Vinegar that includes various active yeasts and bacteria that assist in turning the juice into acetic acid (vinegar).
How Balsamic Vinegar Is Aged:
Aging is the second component that separates balsamic from all other vinegars.
- The cooked must is then placed in the first of a series of progressively smaller wooden casks, called the batteria, or barrel battery, to age. The largest barrel can be 60 liters or more, moving down progressively to 50, 40, 30, 24, 20, 16 and 13 liters to the smallest size, 10 liters.
- The batteria can consist of as few as five barrels and as many as ten, depending on the taste of the producer. The woods that can be used are acacia, ash, cherry, chestnut, juniper, mulberry, oak and walnut. Tradizionale Balsamic must be aged in three of these woods.
- The vinegar first goes through alcoholic fermentation and then acetic oxidation. In other words, the sugars turn into alcohol which turns into acid, which converts the liquid into vinegar.
- Each year the vinegar is decanted and transferred to different casks of progressively smaller sizes so that it can absorb unique flavors from each of the woods. This is called “topping off,” and takes place in January and February. Because of the topping off, Balsamic Vinegar will always contain some new vinegar.
- For the rest of the year, the vinegar is left to age. Each year it reduces in volume through evaporation, concentrating as it ages and resulting in a rich, syrupy viscosity and aromatic bouquet. The barrels are filled to two-thirds to three-quarters capacity, to abet evaporation and condensation.
- For years, the vinegar goes through what is called “maturation” in the middle part of the batteria, then enters the aging phase in the last few barrels. For tradizionales, the ultimate step is decanting into the smallest barrel, where the vinegar rests and matures.
- The process of knowing when to transfer the vinegar to the next barrel is knowledge passed on from artisan to artisan through the generations. While today there are some 200 commercial producers of Balsamic Vinegar, at home the vinegar is made by the women of the household (Rezdòra). There, the aging process occurs in the attic of the house, the barn, or, for commercial family ventures, the acetaia (vinegar house). There are 13th-century paintings depicting the batteria in the attic.
- The attic was an ideal aging location for Traditional Balsamic Vinegar because of the extreme fluctuations in temperatures in Modena, hot summers and cold winters. Unlike wine, cheese and other products that require consistency of climate (and are aged below the ground in cellars to achieve that consistency), the aging process of Balsamic Vinegar actually benefits from the alternating summer heat and the winter cold. Heat promotes fermentation and acetification, and cold allows resting and maturation. This “natural chemistry” allows Balsamic Vinegar to develop and improve for decades, even centuries.
- With an evaporation rate of about 10% each year, 100 liters (26.4 gallons) of grape must will become 15 liters (4 gallons) of vinegar after twelve years of aging. In home production, when the flavor is found acceptably intense, the vinegar is sealed in a final small wooden cask. Commercially, it is bottled in glass flasks.
While the quality of the balsamic depends on the quality of the grapes and the length of the aging process, the final flavor depends on the timing of the transfer of the vinegar to the ever-smaller barrels, and the wood from which the barrels are made. These wood types and the stage of the aging in which they are employed influence the aromas of the Balsamic Vinegar: It is the knowledge and skill of the artisan that ultimately makes the greatest balsamic. As with wine making, vinegar masters aim for particular flavors a balance of juniper, oak and cherry wood flavors, for example.
The Seal of Approval:
Before it is bottled for sale, each artisan producer presents his barrel(s) to the Consorzio. A panel of five “masters” tastes the balsamic “blind” (i.e., the identity of the producer is not known) to ensure it meets the specific criteria of production and quality. The panel members usually sit at individual stations separated by privacy panels, and are provided with a candle, a ceramic spoon, bread and water to clear the palate and a checklist. A series of up to 90 tests is performed by each taster, focusing on visual aspects, aroma and flavor. After each taster rates the samples, the scores are averaged and the group discusses each sample. If it gets enough points, the barrel is accepted and bottled. On a scale of 400 points, 229 are required for 12-year-olds, 255 for 25-year-olds. Rejected bottles are returned to the producer for further aging and adjustment.
Stringent requirements don’t end here, however: Both the design of the hand-blown bottle and the storage conditions are rigidly dictated.
- To be sure that what is approved is what is gets bottled, the approved batch never leaves the supervision of the Consortium: They bottle and label it, and give each bottle a seal and a number. Twelve-year-old bottles get ivory or red caps with the D.O.P. initials (Denominazione di Origine Protetta, Protected designation of Origin), 25-year-olds get gold caps. Numbered bottles of three different quality levels of Tradizionale vinegar of reggio Emilia: red seal, silver seal and gold seal.
- Each bottle’s number is recorded: It can be tracked. Each member has an allocation and cannot sell more than his registered production capacity.
- The bottles are numbered and labeled with one of three different colored labels indicating the quality of the artisan vinegar. They will be entitled to the label, aceto balsamico tradizionale. Making fine balsamic is a time-intensive process, not only in the initial production, but in maintaining the stock over the years until it is ready for release. It explains the high price for such a small amount of vinegar.
Just as no two good wines taste the same, no two artisanal balsamics will taste the same. Each has been decanted into several different barrels and varieties of wood. The casks are highly prized and many are hundreds of years old. The interiors are shaved down and when a cask deteriorates, the artisan will use the salvageable parts in the production of a new cask to preserve as much of the aged and seasoned wood as possible, even if all that can be preserved is a rib or two.