The wine world is constantly evolving, adapting to climate challenges and environmental concerns. In this context, new terms are emerging to describe the grape varieties shaping the future of viticulture. Understanding this glossary is essential to grasping ongoing innovations and the potential of tomorrow's vineyards.

Defining Next-Generation Grape Varieties

The so-called "grape varieties of tomorrow" encompass several categories developed to meet current challenges, particularly the reduction of plant protection treatments. Among them, the term PIWI (Pilzwiderstandsfähig in German, meaning "fungus-resistant") refers to varieties specifically bred for their natural resistance to fungal diseases such as downy mildew and powdery mildew. They often result from complex crossings, sometimes involving wild vines and traditional Vitis vinifera. These developments aim to enable more environmentally friendly viticulture, with fewer chemical interventions in the vineyard.

The Distinction Between Resistance and Tolerance in Grape Varieties

Although often used interchangeably, the concepts of resistance and tolerance carry distinct meanings in viticulture. A grape variety is considered resistant when it is able to prevent or limit the development of a pathogen through specific genetic mechanisms that block its invasion or spread. In contrast, a variety is tolerant if it can withstand the presence of a pathogen without significant detriment to its yield or crop quality. It can host the pathogen, but the consequences on the vine are minimal. Resistance implies an absence of disease or very weak manifestation, whereas tolerance allows the vine to live with it.

The Different Generations of Resistant Grape Varieties

The history of resistant grape varieties dates back to crossings carried out after the phylloxera crisis in the 19th century, seeking varieties that combined resistance and viticultural quality. These early attempts often resulted in "direct producer hybrids", which were sometimes banned due to their "foxy" taste or other undesirable characteristics, such as the Baco rouge (hybrid) grape variety or the Clinton hybrid. Next-generation varieties, such as the Bouquet varieties, represent the culmination of decades of research. They are obtained through successive crossings between Vitis vinifera and resistant varieties, increasing the proportion of the V. vinifera genome at each stage. Bouquet varieties, for example, can contain over 99% of the V. vinifera genome after five to six generations, making them very close to traditional grape varieties in terms of organoleptic and agronomic quality, while maintaining strong resistance to downy and powdery mildew. For a concrete example of this approach, discover Bouquet 3179-90-7 N (Grenache progeny). To learn more about the trial framework that validated these varieties, read our article on Oscar Oc: the framework that validated the Bouquet varieties.

Monogenic vs Polygenic Resistance

Grape variety resistance can be monogenic or polygenic. Monogenic resistance (or mono-resistance) means that protection against a disease is controlled by a single gene. While this approach can be achieved relatively quickly, it carries a risk: the pathogen can develop the ability to overcome this single resistance, eventually rendering it ineffective. This is somewhat what happens with certain downy and powdery mildew-tolerant varieties, where new strains could emerge. Conversely, polygenic resistance is conferred by several different genes working together. This multiplicity of defence mechanisms makes the resistance far more stable and durable against evolving pathogens, providing greater security for the vineyard.

Misconceptions About Resistant and Hybrid Grape Varieties

For a long time, hybrid grape varieties suffered from a negative reputation, often associated with poor quality or undesirable flavours. Modern resistant grape varieties, particularly PIWIs, aim to shatter these prejudices. Thanks to rigorous breeding programmes and intelligent crossings, new generations offer complex and diverse sensory profiles capable of producing high-quality wines. The confusion between the "direct producer hybrids" of the past and contemporary resistant varieties—which boast a high percentage of Vitis vinifera genome—is a persistent misconception. The goal is to integrate these varieties without quota restrictions, as should be the case for certain Bouquet varieties from 2025, thus recognising their agronomic and oenological value, as well as their role in adapting viticulture to ecological challenges.

Château Cazebonne is actively engaged in this approach of innovation and heritage preservation. Our commitment is reflected in the reintroduction of forgotten Bordeaux grape varieties, a long-term endeavour to explore and promote the genetic wealth of our region. To find out more about this approach and the history of vines in Bordeaux, we invite you to download our book on the history of grape varieties, or test your knowledge with our wine quizzes. Every bottle you enjoy supports this project—you can discover our wines online.