We often emphasise how vegetable tanned leather with tannins is to be preferred over synthetic materials and other leathers tanned with mineral-based products. Its elegance, beauty, unique scent and touch improve over time, taking on traces of our lives.
Used for the production of bags, shoes and accessories, the advantage of vegetable tanning is not only due to a simple aesthetic element, nor to the prestige it gives to the products and brands that have chosen it for their leathers. Its distinctive trait lies precisely in its sustainability.
In fact, vegetable tanned leather guarantees the absence of harmful substances such as azo dyes, nickel or pentachlorophenol and chromium VI, which are harmful not only to humans but also to the environment.
Furthermore, most of the substances used during the processing of veg-tan leathers can be recovered, processed and reused in other sectors. For example, the hair taken from the raw hides is transformed into fertilizer for agriculture while the sludge, coming from waste treatment plants, is used in the construction sector to make bricks.
But the sustainability of vegetable tanning starts with the most important product used in tanning: natural tannins, polyphenols widely present throughout the plant kingdom that allow hides to be transformed into a durable material.
The tannin extraction process is completely sustainable and is subject to protocols designed to protect the ecosystem. The trees used come from forests which are managed according to strict regulations set up by national forest authorities. There is a symbiotic relationship between the producers of tannin and the forests, since the survival of the companies depends on the well-being of the plants that supply this precious resource. Preserving forests means investing in the future of our planet!
Tannin is present in all plant species, but some plants are preferred for extraction, including chestnut and quebracho trees. Chestnut trees are particularly suitable because after being cut, they do not die and regenerate themselves quickly by emitting new shoots from the base of the trunk. Tannin can be extracted not only from wood but also from fruits such as Tara pods, harvested from a tree that grows spontaneously in Peru. Other common sources are the so-called ‘gall-nuts’ of Turkish and Chinese origin, external growths that are used by some trees, usually oaks, as a defense mechanism against viruses and bacteria, and whose extraction does not involve any damage to the plant structure.
Among the most utilised areas for tannin extraction we find:
- Chestnut groves in Europe found mostly Italy, between Piedmont, Liguria and Tuscany, but also in France. The woods are cut every 25-30 years according to specific local regulations: the origin of each trunk is traced, and it must meet certain age and diameter requirements. To date, in the main supply areas, less than 10% of the potential vegetative growth of the chestnut groves is used for tannin production, making this practice sustainable in the long-run.
- Quebracho forests located in the province of Chaco and Formosa, in northern Argentina. Here too there are strict rules regarding the number of trees to be felled and the minimum diameter of the trunks. Through a selective cutting practice, carried out every 40 years, only 0.1% of the quebracho specimens per hectare are selected for harvest.
The production of tannins offers enormous benefits to the ecosystem, as well as the fauna and communities living in these wooded areas. The possibility of extracting tannin obliges us to consider forests not only as an environmental heritage but also as an economic asset, encouraging their protection against aggressive forms of land exploitation, such as the notorious “slash-and-burn” agriculture.
Furthermore, the lack of effective forest management can have catastrophic effects on plant welfare. For example, starting from the twentieth century, the progressive abandonment of rural villages and the consequent lack of interest in chestnut grove has had worrying effects on the entire ecosystem, leaving them prey to parasites and diseases. The sustainable management of forests for the extraction of tannin, on the other hand, has allowed their preservation.
But the sustainability of tannins is not limited to forest management. Tannins are extracted simply, using only water and wood. On top of this, these products are reutilised, reducing water consumption and giving new life to waste materials. For example, exhausted wood is transformed into 100% natural pellets that do not contain additional chemical additives, bleaching or dyeing agents.
We all know that the indiscriminate destruction of forests is one of the main causes of climate change, but taking care of them is necessary for both man and the environment. This is why we believe it is important to understand and encourage economic development initiatives based on this balance.