Bordeaux Grape Varieties to Withstand a Warmer World

Bordeaux grape growers had a problem on their hands. Their grapes were becoming increasingly higher in sugar content leading to a wine with higher alcohol levels. The numbers have crept up to 13.5%, 14.5% and even 15% in the 2018 Bordeaux vintage. The increase in alcohol content affects the flavor profile, the acidity, structure and aromatics that the world has come to associate with classic Bordeaux.
The question was what to do to address this problem. On January 26, 2021, the Institut National de l’Origine et de la Qualité (INAO), a division of France’s Ministry of Agriculture approved 4 red varieties and 2 white varieties that will be allowed to grow in Bordeaux. This announcement represents the culmination of over a decade of research by wine scientists and growers of Bordeaux to address the impact of climate change through highly innovative, eco-friendly measures.
Over the past decade, more than 52 varieties of grapes were subjected to scrutiny and six varieties made the final cut. These six varieties are limited to 5% of the planted vineyard area and cannot account for more than 10% of the final blend of any given color. The legal regulations for labelling means that those varieties will not appear on Bordeaux labels.
New Red Varieties
Arinarnoa The result of a cross between Tannat and Cabernet Sauvignon, Arinarnoa is known for its steady production, large bunches and late bud burst. It is resistant to grey rot. It adapts well to climate changes, producing low sugar levels and good acidity. Wines are well structured, colorful and tannic, with complex, persistent aromas.
Castets
Origin: Southwestern France, possibly in Gironde
This historical and long-forgotten Bordeaux grape variety is less susceptible to grey rot, odium and especially powdery mildew, hence its indisputable environmental interest. Wines are colorful and suitable for aging.
Marselan
Origin: INRA 1961
A cross between Cabernet Sauvignon and Grenache, this late-ripening variety is at lower risk of suffering from spring frost and follows a conventional pattern with respect to harvesting dates for the Bordeaux vineyards. It adapts well to climate changes and has proven to be less susceptible to grey rot, odium and mites. Wines are high quality, colorful, distinctive and suitable for ageing.
Touriga Nacional
Origin: Portugal
A very late-ripening variety born in the Dâo and important in the Douro, Touriga Nacional is less at risk of suffering from spring frost, allowing later harvesting and adapts to climate changes. It is not particularly susceptible to most fungal diseases, except for grapevine dead arm. Wines are of excellent quality, complex, aromatic, full-bodied, structured, colorful and suitable for ageing.
New White Varieties
Alvarinho
Origin: Portugal/Spain
The pronounced aromatic qualities of the Portuguese Alvarinho grape variety can be used to make up for the loss of flavor usually caused by hot weather. Its ability to adapt to climatic events makes it less susceptible to grey rot. Its average potential in sugar provides subtle, aromatic wines with good acidity.
Liliorila
Origin: INRA 1956
Like Alvarinho, the pronounced aromatic qualities of Liliorila can be used to make up for the loss of flavor usually caused by hot weather. A cross between Baroque and Chardonnay, it is less susceptible to grey rot. Wines are flowery, powerful and aromatic.

References:
1. Roger Voss and Kathleen Buckley, Beverage Industry Enthusiast, Bordeaux Aims to Protect its Future with New Grape Varieties
2. Wine Industry Network, Bordeaux Receives National Approval to Introduce Six New Red and White Grape Varieties in 2021, January 26, 2021.