Understanding veraison!

What exactly is veraison?

Veraison is the moment when grapes begin to change color, a sign that the ripening process has begun. At this stage, the berries become softer, change color (from green to red, blue or yellow depending on the grape variety), and begin to accumulate sugar, followed by a decrease in acidity and, finally, the development of aromas. This is an essential stage for our grapes, before they eventually give birth to our Saint-Nicolas-de-Bourgueil wines.

When does veraison occur?

This phenomenon generally occurs between mid-July and early August, but the exact date depends on the grape variety, the terroir, the year's climate, and vineyard management. The photo perfectly shows this color transition, typical of a Cabernet Franc grape variety from the Saint Nicolas de Bourgueil vineyard during veraison:

Why is veraison so important for the winegrower?

Veraison is much more than a simple visual change, as it marks the transition from the growth phase to the ripening phase. For winegrowers, it is a crucial indicator, allowing them to:

• Estimate the harvest date (approximately 40 to 60 days later).
• Adjust canopy management.
• Anticipate potential problems on the bunches (diseases, etc.).

How does veraison manifest itself concretely?

It occurs gradually on each bunch, not instantaneously. We often speak of "beginning of veraison" and "end of veraison."

💡 On the same bunch, you can simultaneously observe berries that are still green, pink berries, and berries that are already deep red or bluish. This is called heterogeneous veraison, visible in this photo:

What factors influence veraison?

Several elements play a role:

• Climate: heat accelerates the process.
• Water stress: a vine lacking water may experience delayed or slowed veraison.
• Bunch load: the heavier the vine's load, the slower and more uneven veraison can be.

And after veraison?

Once veraison is complete, the grapes begin to concentrate fermentable sugars and develop their aromatic characteristics. This is the home stretch before the harvest. Maturity checks will then intensify: weight, acidity, sugar, berry tasting... every detail counts!