Combating Climate Change in Bordeaux: From Varietal Mix to Vineyard Practices
When you hear about Bordeaux wine, you think about the classic wine made from a blend of traditional wine grapes. How will climate change impact the wine? Will Bordeaux be forced to reinvent it yet again?
Traditional Bordeaux Varietals
Because Bordeaux is so famous, consumers know what to expect when buying a bottle: long-lived aromatic wines with good acidity and structure.
But, modern Bordeaux wines taste nothing like they did in 1855 when the wine classification system was created. Wines were lighter in style and included higher amounts of Malbec and Carménère in the blends.
The phylloxera pest and severe weather both led to changes in the wine. Before Phylloxera hit (1869 to 1880,) Cabernet Sauvignon, Petit Verdot, Malbec and Carménère were the prominent varieties.
As the region recovered from phylloxera, Cabernet Sauvignon, Merlot, and Cabernet Franc took over. Then came the terrible cold spell in 1956 which wiped out Malbec.
Today, Bordeaux produces red, white, sweet, and even some sparkling wines. The table below shows the primary red grape varieties for both Left Bank and Right Bank wines.
| Left Bank | Right Bank |
| Cabernet Sauvignon (dominant) | Merlot (dominant) |
| Merlot | Cabernet Franc |
| Cabernet Franc | Cabernet Sauvignon (in some blends) |
Some growers still produce small amounts of Petit Verdot, Malbec, and Carménère.
The main white grapes are Sémillon and Sauvignon Blanc. Other approved but less used white grapes include Muscadelle, Colombard, Merlot Blanc, Sauvignon Gris, Ugni Blanc, and Mauzac.
How Climate Change Affects Grapes
Red Varieties:
- Merlot, making up over 65% of total grape production, is at the highest risk for climate change. It makes a friendly, fruity wine with lower tannins and acidity. It buds early so it can suffer from spring frosts. Merlot doesn’t handle drought or heat well. With thin skins, it can rot in humid weather.
- Cabernet Sauvignon, making up about 20% of production, has high tannins giving the wine good structure. This heat-loving grape is less affected by frost because it ripens later. It doesn’t like humid weather or mildew. We may see more Cabernet Sauvignon on the Right Bank in the future, where it hasn’t ripened well historically.
- Cabernet Franc creates wines with good acidity and tannins. On the Right Bank, It thrives in places with a good amount of clay in the soil. Producers are using higher portions of Cabernet Franc in the blends to compensate for Merlot.
- Like Cabernet Sauvignon, Petit Verdot can handle the heat and it also ripens later, but it doesn’t do well during drought. Producers are adding more Petit Verdot to current blends.
White Varieties:
- Aromatic Sauvignon Blanc is a high acid grape that loses acidity in hot, humid weather. Without acidity, wines turn flabby and flat.
- Sémillon, though important, doesn’t dominate as in the past. It could make a comeback because it can handle hot, though not humid, weather.
Climate Change in Bordeaux
According to Tim Sykes of The Wine Society, the average August temperature in Bordeaux in 2019 increased to 28.4 C (83.1 F.) Between 1981 and 2010, the average August temperature was only 21.7 C (71.1 F) This huge temperature increase is stressing the region’s wine grapes.
Grapes accumulate more sugar in hotter weather, which leads to higher alcohol levels. Bordeaux’s traditional alcohol hovered around 12.5% when grapes struggled to ripen. But today, the average alcohol tops 14.5%. Wines are much bigger and riper. As the region gets hotter, acidity could suffer resulting in unbalanced wines.
Bordeaux, and much of France, saw severe frost damage in early April this year, which will lead to reduced harvests. The last heavy frost impacting bud break was in 2017. Frost, mildew, hail, and drought are increasing because of the variability climate change brings.
New Grapes Offer Options
Grape growers and winemakers have monitored changing climate conditions for years. Over the past 11 years, researchers tested 52 different grape varieties, excluding prohibited varieties. Iconic grapes from other French regions, like Syrah and Chardonnay, are prohibited in Bordeaux.
The goal is to find grapes that can thrive in warmer, drier weather, resist drought and disease, and create balanced wines.
In 2019, the winemakers in the Bordeaux and Bordeaux Supérieur AOCs decided to add new grape varieties to their blends.
France’s regulatory body, The Institut National de l’Origine et de la Qualité (INAO), approved seven new grapes in January 2021. The term lasts ten years, allowing growers and winemakers to test the results. Participation is voluntary.
Producers can add up to 10% of the new varieties to the wine but can’t show them on the label. Growers can plant up to 5% of their vineyards with the new grapes.
Approved Red Grapes:
- Touriga Nacional from Portugal is the grape of the famous Port wine. It grows well in hot conditions, ripens late, and is disease-resistant. Touriga creates long-lived, balanced, aromatic, and complex wines.
- Arinaroa comes from the Madiran region of southwest France. This cross between Cabernet Sauvignon and Tannat has good acidity and can resist frost and mildew. Adding tannin and structure to the wine, Arinaroa might supplement Cabernet Franc.
- Marcellan, a cross between Cabernet Sauvignon and Grenache, is from the Languedoc and Southern Rhone. It grows well in hot weather, resists disease, and ripens late. Marcellan can create high-quality long-aged wines.
- Castets, from southwest France, is disease-resistant, and produces long-aged wines with good color.
Approved White Grapes:
- Albarinho, from Portugal and Spain, is a rot-resistant variety. It can supplement Sauvignon Blanc because of good acidity and citrus and stone fruit aromas.
- Lilorila is a cross between Chardonnay and Baroque. Disease-resistant, it creates powerful and aromatic wines.
The selection process for the new varieties excluded many other French grapes which are more suitable to the terroir in Bordeaux.
Some of the approved grapes might not thrive in Bordeaux's terroir. For example, Touriga Nacional prefers a hotter climate than that of Bordeaux.
Additional tests are ongoing with other varieties, but these will take another decade for results.
Changing Vineyard Practices
Adding new grape varieties is not the only solution for mitigating the effects of climate change. Growers and producers are working with sustainability, organics, biodynamics, and regenerative agriculture.
New practices include:
- Changing the canopy by keeping the leaves and reducing sun exposure. Growers used to remove leaves to allow more sun to ripen the grapes.
- Reducing the use of green harvesting (dropping fruit), which allowed for riper grapes and higher concentration.
- Growing grass between vine rows to help manage water. Grasses take up excess water from the roots of the vines.
- Planting vines closer to the ground to reduce sun exposure.
- Irrigating vineyards has been prohibited but is under consideration because of the increasing risk of drought.
- Propagating vines using massal selection from old vines.
- Harvesting earlier and at night, delaying pruning, and planting at lower density.
- In the cellar, fermenting in whole bunches to lower alcohol in the final wine.
Change Will Come to Bordeaux Wine
Will changes in grape varieties, vineyard practices, and production methods, alter the character of Bordeaux wine?
The goal remains to maintain the characteristics of what makes Bordeaux unique even in the face of a changing climate.
Bordeaux has proven its ability to adapt over the centuries and the industry will continue to evolve.
Big Hammer Wines encourages new and existing wine drinkers to explore the fascinating world of Bordeaux wine.
Click Here to Explore the Bordeaux Collection
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