“ Essences ”: the woods used to manufacture casks

As promised, today we talk about wood.
The casks (or barrels) can potentially be manufactured with any kind of wood from any tree but, obviously, they are not all the same! The tightness of liquids (potential losses), the aroma transfer to the product (more or less likeable), the resistance to contamination from insects and bacterias etc. can vary. Substantially, as we stated, every wood is an independent world.
In the world of the balsamic vinegar the most diffused essences are Chestnut, Mulberry, sessile Oak, Juniper, Cherry, but also Ash and Black Locust in some cases.
The following description is taken from “Notes on productive technology of Traditional Balsamic Vinegar of Reggio Emilia” by Renato Bertani – The Traditional Balsamic Vinegar of Reggio Emilia brotherhood.
Chestnut: quite compact wood, white coloured when cut, very rich in tannin. The manufactured barrels have an excellent tightness, they are particularly appreciated for the balsamic vinegar because the chestnut wood is able to lend colour and to accelerate the maturation process.
Mulberry: quite porous wood, straw-yellow coloured when cut, that then evolves into reddish-brown. It is an excellent wood that thanks to its porousness facilitates the balsamic concentration.
sessile Oak: neutral to aromas, this wood, strong and compact, limits the exchanges with the outside, preserving the product very well.
Juniper: very aromatic wood. At present it is very difficult to find casks made of this material because of rules that aim at safeguarding species from extinction. It lends a very appreciated aroma to the Traditional Balsamic Vinegar of Reggio Emilia, the small fine casks that conclude the arrays can be manufactured with this wood.
Thuja: aromatic wood sometimes used as an alternative to the Juniper. It is to be avoided since it transfers unpleasant aromas.
Ash: compact wood, white, devoid of tannin and suitable for the preservation of the product.
Cherry: rose-coloured wood, with delicate aromas.
Black locust: light yellow coloured, compact, very durable. The manufactured barrels have an excellent tightness and duration.
In my case, I chose at first a cask made of Mulberry and then a second one made of Chestnut. How it is possible to notice from my pictures below, the “circles” are different, made of steel those clearer of the Mulberry cask and made of iron those black of the Chestnut cask. Broadly, iron is better because it facilitates the periodic maintenance process of the casks in which the circles have to be thrown: hammer them towards the centre of the cask so that the tightness can be improved.
This process is necessary due to the elasticity to which the cask is subjected because of the alternation of seasons: summer evaporation dampens the staves, enlarging them, while the coldness of winter dries the staves, restricting them. The movements can weaken the tightness of the cask and a periodic servicing can be necessary.

THE WOOD OF THE BARRELS

The choice of the suitable wood with which building a vinegar factory is fundamental for its personalization as well as an occasion to decide a priori the characteristics of the product we are going to create. The multi-centenary practice made clear that not all woods, suitable to manufacture containers, are suitable as well for the containment and the enhancement of the processes tied to the balsamic. Important woods like for example the Walnut are excluded from the category of the usable ones, while apparently humbler woods are valuable for the balsamic coopers. The observation and the experimentation made by numerous generations of valuable artisans, highly diffused a long time ago because of the ample use of containers made of wood, allowed the certain identification of virtues and defects, if there are, of the wooded essences with which the casks of the balsamic are built.

The Chestnut, gentle, malleable but with a good tightness, is able, thanks to its tannin, to give the vinegar the dark intensity of the colour. White when just kneaded, it gradually gains darker and darker shades. With its complex and not always perfectly regular veining, it remains one of the most appreciated woods.
The Chestnut is typical of the northern area of the Apennines. It is an enduring tree with remarkable dimensions and it has been for centuries a sustenance in the scarce resources of the mountain. Its malleable and long-lasting wood is widely used to manufacture barrels.

The Black Locust, solid, strong and compact wood. Suitable for an ultra-centenary usage since it guarantees an almost perfect tightness. Straw-yellow coloured tending gradually to become amber-coloured. From the balsamic point of view, it gives a remarkable contribution to the acidification.
The pseudo Acacia Black Locust forms spots close to water courses and it is characterized by its sculpted bark. It is a leguminous plant that is spontaneously diffused over the banks and in the hills and it has a very heavy and durable wood. The Ark of the Covenant was made of Acacia.

The Cherry, refined, it has a fine aroma that resembles that of black cherry. It is a maneuverable, fine and beautiful wood with a rose coloration. Many producers have or are settling monochromatic arrays made of this essence, since it has been verified that the balsamic vinegar gains a particular and unmistakable aromatic benefit thanks to this union.
Extended parcels of cherry cultivation rise in the Vignola area just before the Spilamberto village, cradle of the balsamic vinegar, precisely in the graft of the valley on the incipient hills of Modena. It is a tree of medium size, rarely exceeds 15 metres of height and, because of its idiosyncrasy for pruning, it is generally cultivated in an almost spontaneous way with open expansion tanks. So the formidable show during the blossoming months gets many visitors together, who converge from anywhere to insure themselves this engaging and unusual sight.

The Juniper, pleasure and pain of the vinegar factory. Many disputes came in succession on its usage according to the tradition, because if on one side the unmistakable aroma gives the vinegar a marked and immediate characteristic, on the other side its “intrusiveness” is not always desirable since they are usually preferred contributions from other, more neutral, woods, so that there is a less evident effect on the product. It remains anyway one of the most valued woods in the vinegar factories, also for the simple reason that it is not currently easy to find, for useful markings of this evergreen are difficult to find, at least in the Apennine areas of Emilia in which in the past centuries there was no problem for the supply. The ones who have a barrel made of Juniper usually guards it very carefully.
The Juniper is an evergreen with no large dimensions, spontaneous in many Apennine areas, lately it is difficult to find because of the scarceness in number and because of the insufficient size of the last specimens. With its resinous and long-lasting wood, it enjoys widespread appreciation in the vinegar factories.

The Ash, heavy, compact, with a hard fibre. It is a neutral wood because it does transmit to the balsamic vinegar no tannin, since it is devoid of it. Indeed its whiteness facilitates itself the acidity, without altering the colour.
The Ash is a wooded essence that has always been an integral part of the old woody areas of the provinces of the balsamic. It is a tree with a dynamic growth that can reach remarkable dimensions and its very white wood is widely used in the joinery area and thus encouraged. In the local iconography it often appears, to prove its endemic presence, in frescos, canvas and paintings from the past and in heraldry as well.

The Mulberry, widely present in the past since it was often used in the “piantate”, the rows put at the borders of agricultural properties. The choice of cultivating this tree was supported by the activity of cultivating silkworms that served as a complement for the poor familiar balance of the farmer. When this production disappeared, already before the First World War, the Mulberry remained in the vinegar factory anyway because thanks to porousness due to the large spring circles, improves a rapid balsamic concentration.
Intense yellow-coloured when cut, it oxidises rapidly becoming dark reddish-coloured. Pliable and maneuverable.
The Mulberry, medium sized tree planted intensively in the 19th century because of the spreading of the silkworms market in our areas. To make their domestic balance, the housewives “andavano alla foglia”, meaning that they took the leaves of this tree with which they nourished their precious larvas in the apposite containers. Porous wood with ample spring circles and the leaves resembling the vine, they are easily attacked by insects.

The sessile Oak, wood for barrels par excellence. Its compact and durable fibre and its hazelnut colour are, along with its long-lasting and non-intrusive aromas, the best e desirable requirements to house the most matured balsamic vinegar. It is usually useful in any position of the array. The barriques are made of sessile Oak, too.

The Oak has always been considered the tree par excellence. In our area the toponymy too, with example of Rovereto di Modena, reveals that a long time ago there must have been extended woods of this essence. The most frequent varieties are the English Oak, a sort of oak from damped areas, a majestic and enduring tree that can reach 30 metres of height, the sessile Oak, named “robur” because of its resistance, diffused in the hills, the same as the downy Oak that, despite its name, reaches remarkable dimensions.

Thanks To: Acetaia Giusti