How Balsamic Vinegar is Made? The secrets of Balsamic Vinegar production in the provinces of Modena and Reggio Emilia. Everything you need to know, from harvesting the grapes to the bottling.
Vinegar is a word that can evoke several ideas: the first is that of a product that we take for granted, a dressing to be used with a dropper in salads and for a thousand other uses at home, as if it were a classic low-quality white wine vinegar. There is apple vinegar, which is very much in fashion amongst the health-conscious because of its supposed healing properties believed to improve the absorption of sugars and fats, when taken before meals.
There are different types of vinegar which are even less known, such as the one made with apple cider, sherry and many other fermented drinks.
The king of vinegars, however, is Balsamic Vinegar: a type of vinegar which is now famous in all gourmet kitchens and that many try to imitate. Yet it is difficult to be wrong: the real Balsamic Vinegar is the IGP or DOP one that is the Balsamic Vinegar that has been produced, according to strict specifications, in the provinces of Modena and Reggio Emilia for centuries.
A product with a unique taste, much more than a normal vinegar; the result of a long and complex process that gives it unique flavours and aromas.
In order to better understand the uniqueness of Balsamic Vinegar, it is important to know how balsamic vinegar is made.
The origin of the product: the types of grapes and their selection
There are three types of Balsamic Vinegar which are officially regulated: the Balsamic Vinegar of Modena IGP and the Traditional Balsamic Vinegar DOP of Modena and Reggio Emilia.
The IGP is produced from grapes of Lambrusco, Sangiovese, Trebbiano, Albana, Ancellotta, Fortana and Montuni.
The Traditional DOP of Modena and Reggio Emilia instead requires Lambrusco, Ancellotta, Trebbiano, Sauvignon, Berzemino, Sgavetta and Occhio di Gatta grapes with the additional condition that they must be grown within the traditional territories of the two provinces.
Both DOPs must also be produced with grapes from vineyards with a production of no more than 160 quintals per hectare: this is done in order to give priority to productions focused on quality and quantity.
Traditionally, the harvest is carried out in the periods of September and October: the exact date is determined by the climatic conditions of the whole year which has just passed. When the expert winegrowers establish that the grapes are ripe, the harvest begins: it is usually carried out during the least hot hours of the day and either by hand or mechanically, while taking the necessary precautions. In fact, from the moment of harvesting to crushing, very little time must pass in order to prevent unwanted and uncontrolled fermentation processes that would affect quality and taste.
Crushing: fresh must, so raw
The harvested grapes must be cold pressed without any other additives; as we said, everything must be done as quickly as possible from the time of harvesting to prevent the grapes from losing quality.
The must has to have very precise characteristics: it must have at least 15 degrees Brix, i.e. a certain concentration of sugars necessary for fermentation.
The raw must obtained in this way is sieved and ready for the cooking phase: we get into the core of the production phases of Balsamic Vinegar.
Boiling: how to make cooked must
The raw must is placed in open containers placed on the fire and cooked at least 30 degrees for 12-24 hours. We are therefore talking about the real “slow cooking” that reduces the must by two thirds.
The specification for Traditional Balsamic Vinegar DOP of Modena requires a minimum cooking time of 30 minutes, but in practice nobody does it for such short time. Traditionally, it is used long cooking at a temperature which is not too high in order to prevent sugars from crystallizing excessively, risking making the compound uneven or altering the taste of the final product.
Acetification and refinement: alcoholic and acetic fermentation
The production of the Traditional Balsamic Vinegar DOP gets into the heart of the production with the fermentation phases.
The first fermentation is the alcoholic one, in which the protagonists are microorganisms called saccharomyces (the same of the famous brewer’s yeast family).
The saccharomyces feed on the sugars in the must and release ethanol, i.e. alcohol, as a by-product.
The alcoholic fermentation takes place immediately after the must is cooked and then takes place during the winter period, as done with wine.
In past decades a false scientific theory had spread, claiming that alcoholic and acetic fermentation had to take place together, because saccharomyces and acetobacters (naturally present in the fruit) would be “commensal”, i.e. they would feed on each other by making fermentation simultaneous.
Today it has been discovered that this is not true and that, on the contrary, trying to carry out the two steps together in the same barrel only lowers the quality of the product, since the activity of the acetobacters can inhibit that of the saccharomyces.
For this reason today the alcoholic fermentation is carried out in stainless steel casks before being moved, during the acetification phase (which technically is not a real fermentation, but a process of bio-oxidation), into traditional local fine wood barrels (oak, mulberry, juniper, chestnut, cherry) of different sizes called “battery”.
The second phase begins when temperatures rise with the arrival of spring: this is the period when the acetobacters activity starts again, so the fermented and alcoholic must be moved into one of the barrels of the battery (the series of barrels used to produce Balsamic Vinegar). The barrel in which the acetification begins is the largest and it is called the abbess.
The barrels of the battery are built according to a long and laborious process and before being used for acetification they must not be impregnated with vinegar, so that the necessary colonies of acetobacters are grafted into the wood going to facilitate the acetification of the fermented must.
How is the ageing of balsamic vinegar made?
During the ageing phases, tradition wants it that the barrels and kegs remain open on the side of the “cocchiume”, the traditional hole in the centre of a barrel.
In fact, the objective of ageing (and of the decanting) is to obtain a more and more concentrated product, making the superfluous evaporate and condensing aromas and flavours; for this reason, the “cocchiume” remains open. It is also covered with a cloth for cleaning purposes.
Modern studies suggest, however, that during the evaporation from the “cocchiume”, amounts of aromas are lost and that the outside expulsion of watery volume could also occur with the “cocchiume” closed, through the porosity of the wood.
The ageing process of Balsamic Vinegar DOP of Modena and Reggio Emilia must last at least 10 years. During this period of time, the cycle of the seasons is followed, and this is very important for microorganisms; for this reason, the barrels must be exposed to climatic variations and not in isolated and watertight environments.
This is because temperatures above 20 degrees Celsius are necessary for the activity of the acetobacters; these temperatures are also necessary for the evaporation of excess water. At the same time the cold is necessary to avoid excessive evaporation and allows the product to sediment unwanted solid residues on the bottom of the barrel.
These climatic conditions are guaranteed by the Provinces of Modena and Reggio Emilia, which are characterized by cold winters and very hot summers: for this reason, vinegar cellars are often found in attics.
Every year the vinegar is decanted into smaller barrels, according to this procedure: the finished product is that of the last barrel of the battery, aged just long enough to be considered ready. The remaining and not evaporated content from the penultimate barrel is thus moved into the smallest, sometimes the penultimate receives what remains in the third and so on.
Traditionally batteries are composed of an odd number of barrels, over five: even if there is no scientific explanation for the odd number, this habit is perpetuated according to tradition.
How the bottling and labeling of balsamic vinegar is made?
Traditional Balsamic Vinegar DOP of Modena is bottled in glass bottles which have a particular shape, spherical but with a rectangular base of 100 ml; the classic bottle designed by the famous designer Giorgetto Giugiaro. The specification also allows bottling in 200- or 400-ml bottles, which are very rare on the market.
The bottle with the gold capsule is reserved for Extra-Vecchio vinegar (aged at least 25 years), while with a minimum ageing of 12 years the capsules are amaranth-coloured (straw yellow or ivory).
The cap is sealed with a numbered, non-reusable mark.
In the case of Balsamic Vinegar DOP of Reggio Emilia, on the other hand, the bottles have a more elongated shape, similar to an inverted tulip, of 100 ml (the regulations also allow sizes of 50 and 250 ml or single-dose packages of 5-10 ml, very rare on the market) strictly in glass; they are distinguished by the lobster stamp, silver and gold.
The cap is tied with string and it is sealed with sealing wax.
In the IGP Vinegar of Modena instead there are different types of possible bottling. The specification allows different materials such as glass, wood, ceramic or terracotta, with the following capacities: 0,250 l, 0,500 l, 0,750 l, 1 l, 2 l, 3 l, 5 l or in single-dose containers made of plastic or composite materials, with a maximum capacity of 25 ml.
In the labels of both Traditional DOP and IGP it is forbidden to add the year of production, commercial terms that do not reflect any certified quality to be disciplined as extra, super, classic etc…
It can be specified in the case of an Extra Old or Aged DOP for a IGP.
Production of the DOP and IGP: the differences
Explaining in detail and without going into too much detail about how to make Traditional DOP Balsamic Vinegar and make a comparison with the most popular and cheapest IGP is not easy. Obviously, if you read the previous paragraphs, it shows that Traditional DOP Balsamic Vinegar from both Reggio Emilia and Modena meet very detailed specifications on raw materials, procedures to be adopted and bottling.
Although it is a good product, the production of the IGP is not comparable to the DOP: in fact, the specifications have been studied on the basis of the history and tradition of the best Balsamic Vinegar producers in the provinces of Modena and Reggio Emilia to achieve the highest quality. This explains the differences between Traditional DOP and IGP Balsamic Vinegar.
There are many other aspects to be studied in detail regarding how Traditional Balsamic Vinegar DOP and IGP is made. This may be a useful knowledge to educate yourself when choosing the right products and increase your reputation as a gourmet with a great knowledge of some of the best Italian products.