Shifting Winds Threaten Bordeaux's Harvest
A shift in wind direction brings an increased threat to Bordeaux's Harvest. As the massive "Landiras" or "Hostens" wildfire continues to burn in the Gironde region. Though it is not clear which areas of Bordeaux may be impacted, the location of the fire, to the southwest of the city, suggest areas such as Graves and Pessac-Léognan may be most at risk. Satellite imagery, courtesy of NASA, shows smoke over the region August 11.
The wildfire, which reignited on August 10, 2022, has since burned 7,4000 hectares during soaring temperatures in the mid-30s C (94 F) or more. The fire has forced the evacuation of 10,00 people in Belin-Béliet and the closure of the A63 autoroute.
A Fear of "Smoke Taint"
The concern now is the potential for the fruit to be exposed to smoke - creating 'smoke taint'. When exposed to wildfire, the fruit and leaves can absorb smoke compounds, creating an unpleasant taste of smoke and ash or ‘taint’.
Grapes can be negatively impacted with as little as 30 minutes of exposure to smoke, with varietal and timing of the exposure in the growth cycle are important factors. Grapes are particularly vulnerable between veraison and harvest, the current stage in Bordeaux. Once exposed, the available mitigation options are few and are often not very successful.
Limiting the amount of skin contact through cold or shorter macerations (the process of extracting color, tannins and flavors from the skins) may reduce the intensity of the smoke flavor. The addition of wood chips can potentially mask the taint, though the resulting wine may not be representative of the wine maker’s usual style.
Despite the devastating impact, there is relatively little academic research on smoke taint. Scientists are still working to identify the exact pathway by which ‘smoke taint marker compounds’ enter the berries and which compounds are most important. No common industry scale yet exists to quantify smoke taint though the Australian Wine Research Institute is working to create one. The loss of crops to smoke taint in California in 2017 and 2020 has also spurred new research initiatives.
A Long, Dry Season in Bordeaux
The resurgence of this fire comes only two weeks after firefighters brought another large fire, located further west, near the Dune of Pilat, under control. The Bordeaux region, as well as much of southern Europe, has seen unprecedented high temperatures and drought this year.