What is véraison?

Véraison marks an essential and visually identifiable stage in the life cycle of the vine. This is the moment when the grape berries, previously green and hard, begin to change colour and soften. This phenomenon is not just a simple chromatic change; it signals the start of an intense ripening phase, crucial for crafting quality wines.

The key biochemical mechanism of véraison

Beyond the aesthetic aspect, véraison is the starting point for a profound biochemical transformation within the berries. Chlorophyll, responsible for the green colour and photosynthesis, gives way to anthocyanins for black grape varieties, which bring red and purple hues, and to carotenoids for white grape varieties, conferring golden and yellow nuances. Simultaneously, a massive accumulation of sugars begins in the berries, while tartaric and malic acidity progressively decreases.

At the same time, phenolic compounds, notably tannins and aromatic precursors, develop. These elements are fundamental for the structure, colour, aromas, and longevity of the future red Graves wines and white Graves wines. This is a period of great physiological activity for the vine, which is actively preparing its fruit for the harvest.

An indicative timeline for véraison

Véraison generally occurs right in the middle of summer in the vineyards, most often during the months of July and August in the Northern Hemisphere. The exact timing varies depending on several factors: the grape variety (Malbec, Petit Verdot, Cabernet franc, Merlot, etc.), the year's climate, the exposition of the plots, and the vine's crop load. Careful observation is required from winegrowers, as it is a valuable indicator of the vegetative cycle's progress and helps anticipate the harvest date. An even fruit set and good vine health before véraison are guarantees of successful ripening, just like the lignification phenomenon, which is crucial for fortifying young shoots.

Observable signs in the vineyard plots

In the vineyards, véraison first manifests itself with the appearance of a few coloured berries, often on the clusters most exposed to the sun or the earliest to ripen. Gradually, the entire cluster and plot will transform into a mosaic of colours. This heterogeneity is normal and reflects the diversity within a single vine. This is also the moment when the berries become softer to the touch, and their skins thinner. For our teams, these physical changes are the signal that the vine has entered a critical phase requiring increased monitoring.

Véraison at Château Cazebonne and the promotion of biodiversity

At Château Cazebonne, véraison is a particularly closely observed period. It allows us to accurately track the ripening progress of our numerous grape varieties, including those we are reintroducing, heirs to the ancient Bordeaux diversity. Each variety reacts differently to the pedoclimatic conditions, offering a palette of distinct véraisons, further enriching our terroir's uniqueness. This rigorous monitoring guarantees a harvest at optimal ripeness for each plot, essential for the purest expression of our wines. This work is part of our overarching approach aimed at promoting biodiversity and respect for the plant, ensuring better winemaking conditions.

The long-term work we are carrying out at Château Cazebonne to replant grape varieties in Bordeaux that had disappeared is made possible thanks to the support of the many enthusiasts who share our vision and have adopted our wines. To learn more about this fascinating story, we invite you to download the digital version of the book "Bordeaux, une histoire de cépages" by Jean-Baptiste Duquesne, available on our website here. You can also test your knowledge of the wine world by taking part in our oenological quizzes, or simply discover and order our cuvées by visiting our online shop.