Posted: Sunday, 04 June 2023 13:48
TechTalk: Impact of climate change on Trees and Wine Barrels
Gaja gives the example of their winemaker Alessandro Albarello who has been with them for a quarter of century as the oenologist, to help understand the impact of climate change on trees, wood and wine barrels. ‘Alessandro tells us a story about when he learned to swim in the Tanaro River (river that meanders through the vineyards of Barbaresco) as a child’, says Gaja.
Back in the 1980’s his parents ran a recreation club on its banks. There was a lively atmosphere on the river back with canoeing, fishing from the traditional long narrow boats and a real beach culture. But that world no longer exists. Today, passing over the Tanaro means crossing little more than a creek. A dry river bed is one of the clearest signs of climate change.
This oenologist’s kingdom is the cellar and wood is one of his most important tools. He manages the barrels and vats to firstly oversee the fermentation of grapes into wine, and secondly to curate its evolution and maturation. In the context of wine production, wood is one of the elements on which climate change is having a significant impact.
The two most important aspects are increasingly high temperatures and drought. Fifteen years ago there was no need for climate control systems in the cellar since the temperature never reached above 18°C. Today, however, it can get up to 23°C. The problem is that the hotter and drier the environment, the more these barrels affect the wine by releasing overwhelming notes of vanilla. ‘This is why we had to introduce air conditioning and controlled humidity in order to maintain a constant 14-15°C.’ he says.
Alessandro’s favorite barrel in the cellar is a historic 7 ton (7.000 liters) barrel that produces that ‘almost perfect’ wine: It respects the liquid contained inside to perfection. Drought, on the other hand, affects the barrel production process, specifically the maturation stage. This phase begins after the tree has been cut.
For thicker barrels, a longer maturation period is required. As a rule of thumb about one year is needed for each centimeter of wall thickness. The wood seasoning process takes place outdoors and snow is essential as it generates the humidity necessary to contain the tannins that are derived from the wood.
‘If the climate is too dry during maturation, the wood is no longer capable of reducing the bitter tannins. Furthermore, when the matured wood is too dry, its structural qualities become compromised. It can happen with newly arrived barrels that begin to crack and after a few months even split apart.’
Gaja has been buying barrels mainly from an Italian company Gamba and an Austrian company Stockinger. They asked the opinion of these two main barrel manufacturers with whom they collaborate, about the relationship between climate and wood.
Gamba have been master coopers for 7 generations. According to them, ‘careful oak forest management is essential to mitigate the effects of climate change on wood. ‘In forests where there is dynamic tree management and it produces proper oak density, fewer problems arise compared to forests lacking human intervention. We need to maintain a sufficient quantity of trees to establish slow growth and to ensure that they grow tall and straight. In case the oak trees become too many, we’ll need to conduct deforestation.’
In some regions where the forests are at higher altitudes and where there has been less rain, they have stopped buying timber because the quality of tannins and the wood’s elasticity were no longer the same, causing the staves of some of the barrels to crack. ‘Yet due to climate change, other forests, which did not produce quality wood forty years ago, provide today trunks suitable for barrel production’.
Interesting observation about how climate change and global warming can affect the quality of wine through the wood used! These might not be important for the producers in India because of limited knowledge in this aspect but they would do well to focus on this aspect since barrels are used mostly for quality wines and this is one variable they need to understand properly- editor