Rising summer temperatures are impacting grape growers around the world, however today I will focus on France’s Bordeaux region.  Temperatures are expected to rise between 0.3°C and 1.7°C over the next 20 years. At this point global warming has benefited Bordeaux but that is about to change, especially if the grape crop is not somewhat modified. 

Growers are going to need to reconsider their mix of grapes as temperatures continue to rise.  The future of white varietals from the region may become non-existent while the existing proportion of reds, where 60% to 70% is currently Merlot, is already too great an amount.  Merlot is ideal in cooler regions where there is a shorter growing season. However, with temperatures increasing and the growing season getting longer, Merlot now ripens too quickly.  Many of these vines will need to be replaced with varietals such as Cabernet Sauvignon, which perform better in hotter climates with a longer growing season.

At least until now the increase in temperature and the resulting riper fruit have not had a detrimental effect on the quality of the wine. Instead, higher temperatures have made wine quality more consistently better. However, if warming continues the quality of the wine will begin to deteriorate.

It is well known that high temperatures can have harmful effects on grape composition, such as a decrease in anthocyanins (the pigmented molecules that give red wine its colour), as well as other molecules, that could cause unpredictable aromas.  The grape skins are also negatively impacted by higher temperatures.

Growers, scientists, and wine professionals all speculate that continued increases in temperature will negatively impact fruit and wine quality in the future. However, to date Bordeaux has successfully adapted to the quickly changing climate, but experts fear that the danger point is swiftly approaching.

Sláinte mhaith

This summer has proven to be especially bad for the grape harvest in France’s Bordeaux region.  The perfect combination of meteorological conditions has led to an alarming spread of mildew throughout the region. The combination of warm weather and rain has resulted in new plant growth being left unprotected as the wet weather has hindered the application of herbicides.

The mildew has been having the greatest impact on the red grape varietals, most notably Merlot.  So far this year the region has been impacted by two separate waves of mildew.   It remains to be seen whether the disease will progress onto the stalks of bunches and if it can be ultimately contained.

Some growers have lost their entire harvest.  As a result, a helpline has been established to help growers cope with the devastation.  Some grape growers are even considering their careers because of the mildew.  It has been quite traumatic for those trying to control it.

This is the second consecutive year where Bordeaux growers have been impacted by the weather.  The 2022 harvest was about 11% less than the ten-year average.

Grape growers are hoping that the region will soon see a return to more uninterruptedly dry, hot weather.  If the dry heat returns, Bordeaux may see the 2023 harvest being within the top three earliest harvests in the past decade.  However, given the devastation caused by the mildew, the harvest yield will be much lower than in previous years.  This will no doubt impact the price when the 2023 vintage of Bordeaux reaches store shelves in a few years’ time.

Sláinte mhaith