Balsamic vinegar is made of grapes, tradition, passion, history, knowledge and time. The ingredients used to make balsamic vinegar depend on the production method.
There are two kinds of balsamic vinegar:
- Balsamic Vinegar of Modena PGI, usually called by the Italian name Aceto Balsamico di Modena IGP
- Traditional Balsamic Vinegar of Modena PDO and Traditional Balsamic Vinegar of Reggio Emilia PDO usually called by the Italian names Aceto Balsamico Tradizionale di Modena DOP and Aceto Balsamico Tradizionale di Reggio Emilia DOP.
EU geographical identifications, namely Protected Designation of Origin (PDO) and Protected Geographical Identification (PGI) were introduced by the European Commission, respectively in 2000 and 2009, to protect the name, origin, and traceability of balsamic vinegar. The Italian provinces of Modena and Reggio Emilia are the only areas in the world where quality balsamic vinegar is made and where production is strictly regulated and safeguarded by official and authorized processing methods.
Traditional balsamic vinegar: ingredients and production method
Traditional balsamic vinegar is produced in Italy, exclusively in the cities of Modena and Reggio Emilia where the whole production process takes place, from grapes cultivation, harvesting and crushing into must, to fermentation and aging in ancient wooden casks, to bottling and labeling.
The region’s microclimate, soil quality, expertise and tradition have contributed to the success of this centuries-old dark syrupy condiment, the origins of which date back to the Middle Ages, as described in this session on the history of balsamic vinegar.
The complete production process of balsamic vinegar can be segmented as follows:
- Grapes and must
- Harvesting
- Crushing, filtering and settling
- Grape must composition
- Grape must cooking and resting
- Fermentation, maturation and aging
- The best place for balsamic vinegar casks
- Drawing, topping-up and refilling
- Packaging
Grapes and must
In compliance with the production regulations of the Protected Designation of Origin, Traditional Balsamic is made exclusively from grape must grown and harvested in the province of Modena and Reggio Emilia from the authorized varieties of Trebbiano, Pellegrina, Sauvignon, Sgavetta, Barzemino, Occhio di Gatta, Spergola, Ancellotta and Lambrusco. The sugary grapes are crushed and made into must with all the skins, seeds and stems, resulting in a superior balsamic vinegar.
Harvesting
Grapes for balsamic vinegar are harvested in the fall when they are ripe and sugary. Grapes are free of pesticide residues that could alter the alcoholic fermentation and acetic oxidation of the grape must. Hand harvesting is preferred over mechanical harvesting, to preserve integrity of each part of the grape.
Crushing, filtering and settling
A soft crushing of grapes is then carried out, which separates the liquid juice from the solid parts of the bunch and preserves polyphenols, the grape compounds that slow down the acetification process. The must is filtered and allowed to stand for a few hours so that the solid parts settle to the bottom, leaving a clear, purified liquid to emerge.
Grape must composition
The must obtained from grapes consists of 75-85% water, in which various compounds and elements are suspended and dissolved, including:
- Bacteria, single-celled organisms that can transform alcohol into acetic acid;
- Polyphenols and tannins, which give grapes their colored pigments;
- Mineral salts (potassium, calcium, iron);
- Vitamins;
- Yeasts, producing the enzymes that essential for alcoholic fermentation;
- Sugars (glucose and fructose);
- Organic acids.
Grape must cooking and resting
Within 24 hours of crushing, the must filtered from the solid parts is boiled before fermentation begins. While cooking over fire and in open boilers, the must undergoes sterilization and the concentration of sugar increases, favoring the development of fungi, thus converting sugar into alcohol.
The first cooking phase lasts about 30 minutes and allows impurities to rise to the surface and be removed. Next, at a temperature of about 80-90°C, the must is boiled for several hours very slowly to avoid caramelization of the sugars which could cause bitterness, until it reaches the desired degree of thickness. After cooking, the still-warm must is transferred to glass demijohns where it rests throughout the fall and spring, when all the lees and mucilage will be decanted, resulting in a clear liquid.
Fermentation, maturation, aging
After cooking, fermentation, maturation and aging are carried out.
The fermentation phase is made of two steps: first, the alcoholic fermentation is started by the yeasts of the must that partly convert sugars into ethyl alcohol. Later, the acetic oxidation resulting from the action of acetobacteria favor the oxidation of alcohol and its transformation into acetic acid.
These two steps usually take place over 2 or 3 years.
In the so-called maturation phase, important and complex enzymatic transformations occur. Once the yeasts and vinegar bacteria have finished their function, thanks to the enzymes they release, vinegar is enriched with typical aromas and flavors across a period of 10 to 12 years.
With aging, through a series of very complex chemical-physical transformations, all components of the balsamic vinegar harmonize and balance to each other, enhancing and refining the olfactory-tasting peculiarities of vinegar. The time required for this phase is not definite but, through the annual repetition of drawing, topping-up of casks and refilling of grape must it can be prolonged indefinitely with gradually better results.
The best place for balsamic vinegar casks
For centuries, arrays of wooden barrels for balsamic vinegar have been placed in the attics, with large temperature ranges between seasons. Extreme heat and cold favor the processes of making excellent balsamic vinegar. Fresh air enters through small, narrow openings so that oxygen, which activates acetic oxidation, keeps the humidity level low.
The wood for barrels depends on the hardness degree. Hard woods such as oak, durmast, locust and juniper have a low evaporation coefficient and slow down the concentration of the liquid they contain. For this reason, the hardwood barrels are usually placed at the tail end of the cask array, where the balsamic vinegar undergoes limited reduction and requires less oxygenation and tightness.
In contrast, soft, porous woods such as cherry, mulberry, pear, and apple have a high evaporation coefficient and ensure a constant exchange of oxygen with the environment, facilitating fermentation and maximum liquid concentration. Softwood barrels are placed at the head of the cask set, with greater capacity and lower tightness. Finally, semi-hard woods, such as ash and chestnut, are medium-porous and long-lasting and used for the middle casks of the array.
Drawing, topping-up and refilling
The ideal time to put the cooked must into the larger jar is February-March, when fermentation activity is about to begin, possibly on waning crescent moon days, considered the most propitious, and in the absence of wind to avoid raising dust that could contaminate the liquid in the casks.
Once a year, after a thorough analysis, a small quantity of ripe, thick balsamic vinegar is drawn from the smallest barrel and collected for bottling and packaging. Each next larger barrel is then topped up, and the biggest cask is finally refilled with fresh grape must prepared during the previous fall and left to settle during the winter. These operations should never be done before the balsamic vinegar is 12 years old and only limited amounts of balsamic vinegar should be taken out and topped up, so as not to damage the final product left inside the barrels.
Packaging
As already illustrated in this article on the traditional method of production, balsamic vinegar comes in different glass bottles and sealed packages depending on whether it is Traditional Balsamic Vinegar of Modena or Traditional Balsamic Vinegar of Reggio Emilia:
- Traditional Balsamic Vinegar of Modena PDO is packaged in a 100-ml glass bottle with a Giugiaro design and the Traditional Balsamic Vinegar of Reggio Emilia PDO in a 100-ml glass bottle shaped like an upside-down tulip.
Non-traditional Italian balsamic vinegar: ingredients and production method
As described in this session on Balsamic Vinegar of Modena PGI, Balsamic Vinegar of Modena PGI also adheres to an official production method and is produced in the Italian cities of Modena and Reggio Emilia. Unlike the traditional balsamic vinegar described above, this non-traditional, still authorized, modern version of balsamic vinegar is aged from 60 days up to 3 years and the mixing and processing of its ingredients take place within the provinces of Modena or Reggio Emilia. Bottling and labeling, however, can also take place outside the Modena and Reggio Emilia production area. This explains why Balsamic Vinegar of Modena is sometimes branded by non-Italian producers.
The production of GPI Balsamic Vinegar of Modena can be broken down as follows:
- Grape must and other ingredients
- Composition of grape must
- Acetification and finishing
- Aging
- Packaging
Grape must and other ingredients
Balsamic Vinegar of Modena PGI is obtained from partially fermented and/or cooked and/or concentrated grape must. The grapes come exclusively from the vines of Lambrusco, Sangiovese, Trebbiano, Albana, Ancellotta, Fortana and Montuni. The grape must is enriched with up to 10% wine vinegar, and 10-years-old vinegar.
Grape must composition
The minimum percentage of grape must is 20% of the total amount of product to be processed. Cooking continues until the desired degree of thickening is reached, at a temperature of 20°C. The grape must has a minimum overall acidity of 8 g/kg and a minimum net dry extract of 55 g/kg. For colorimetric stabilization, up to a maximum of 2% by volume of the finished product, caramel may be added. The addition of any other substance is prohibited.
Acetification and finishing
Balsamic vinegar is processed by the classic method of acetification with selected bacterial colonies, using special large wooden vats.
The balsamic vinegar is finished in wooden barrels for at least 60 days. At the end of this finishing period, the resulting balsamic vinegar undergoes an analytical and organoleptic examination by a group of technicians and master tasters: this crucial step officially certifies Balsamic Vinegar of Modena PGI.
Aging
Once the 60-day finishing in wooden vats has been completed, Balsamic Vinegar of Modena can undergo a further period of aging. If this continues for more than three years, the finished product can be classified as “aged” (invecchiato).
Packaging
Balsamic Vinegar of Modena is packaged in glass bottles with different capacities: from 250 ml (8.45 fl oz) to 5 L (169.07 fl oz), including 25 ml (0.85 fl oz) disposable sachets. The glass bottle bears the name Balsamic Vinegar of Modena (Aceto Balsamico di Modena) and the blue and yellow seal of the Protected Geographical Identification (PGI).
Is all balsamic vinegar from Italy?
As reported earlier, quality balsamic vinegar is produced only in a restricted area of Italy and its production refers to official methods certified by EU geographical designations that must be scrupulously enforced. Any other production protocol does not refer to real balsamic vinegar and results in poor quality dressing syrups with limited and flat organoleptic characteristics.