Every year, between July and August, the vineyards offer us one of the most visual and symbolic moments of the vine's cycle: veraison.
It is the moment when the grapes begin to change color, leaving behind their intense green to be tinged with reddish, purple, or golden tones, depending on the variety. But beyond its beauty, this phenomenon marks the beginning of a new stage: ripening.
What is veraison and why is it so important?
From an agronomic point of view, veraison is the turning point that defines the end of cell development and the beginning of the physiological ripening of the berry. From this moment on, the plant redistributes its resources: photosynthetic activity in young leaves is reduced, and the transport of photoassimilates to the fruit intensifies.
This change translates into:
- Increased glucose and fructose in the pulp (sugar accumulation).
- Progressive reduction of organic acids (mainly malic).
- Evolution of anthocyanins and tannins in the skin and seeds (phenolic ripening).
- Development of key aromatic precursors for the wine's sensory profile.
In addition, veraison offers practical information for agronomic decision-making. It is a temporary marker that allows adjusting the harvest calendar and anticipating specific treatments if climatic conditions require it.
How to interpret veraison to anticipate the harvest
The development of veraison allows us to anticipate the optimal harvest time, which usually occurs between 15 and 20 days after 100% veraison is reached.
But also, the speed at which this change occurs tells us about the physiological state of the plant:
- Rapid and homogeneous veraison usually indicates a balanced vineyard, with a healthy and well-nourished plant.
- Slow, irregular, or asymmetrical veraison can indicate water stress, excessive yield, or nutritional imbalances that compromise ripening uniformity.
In precision viticulture, monitoring veraison is considered one of the most useful natural metrics for projecting the optimal harvest moment, which typically occurs two to four weeks after full veraison (100% color change) is reached.
The challenge at Clos Pons
At Clos Pons, we work all year with a clear objective: to reach veraison with a healthy and balanced plant. This allows us to ensure homogeneous and complete ripening, key to obtaining grapes with the necessary potential to produce expressive, elegant wines with identity.
Every agronomic decision (from pruning to irrigation management and cluster load) is aimed at accompanying the vine on this journey. A complete and uniform veraison guarantees optimal conditions for slow, progressive, and homogeneous ripening.
This basis is essential for obtaining grapes with good phenolic concentration, balanced acidity, and defined varietal expression. Each veraison represents a critical stage that summarizes the physiological state of the vineyard after months of agronomic work. Its evolution allows evaluating the plant's balance, anticipating adjustments in management, and precisely planning the harvest.
Observing how the grape changes color is not just a visual indicator: it is a key tool for making decisions with a direct impact on the final quality of the wine.
Do you have any questions about this process or how we approach it at Clos Pons? Write to us and we will be happy to answer you.
Very soon we will announce the dates of the harvest day, a unique opportunity to experience another key moment of the annual cycle firsthand. We invite you to follow us on social media or subscribe to our newsletter so you don't miss out.
Sources
- Hrazdina, G., Parsons, G. F. & Mattick, L. R. (1984). Physiological and biochemical events during development and maturation of grape berries. American Journal of Enology and Viticulture, 35(4), 220–227.
See original publication (AJEV) - Cataldo, E., Fucile, M. G. & Mattii, G. B. (2022). Leaf Eco‑Physiological Profile and Berries Technological Traits on Potted Vitis vinifera L. cv Pinot Noir Subordinated to Zeolite Treatments under Drought Stress. Plants, 11(13), 1735. doi:10.3390/plants11131735
See original publication (Plants, MDPI) - Salazar Parra, C. A. (2011). Vid y cambio climático: estudio del proceso de maduración de la baya en respuesta a CO₂, estrés hídrico y temperatura elevada. Doctoral thesis (Tempranillo), University [Name]. Publication not openly available.
See backup on SciSpace - Rafique, R., Ahmad, T. & Ahmed, M. (2023). Exploring key physiological attributes of grapevine cultivars under the influence of seasonal environmental variability. OENO One. [Restricted access] See backup on SciSpace
- Penso, G. A. et al. (2014). Study of the maturation of grapes (Vitis vinifera L.) grown in Dois Vizinhos, Paraná. Semina: Ciências Agrárias. [Restricted access] See backup on SciSpace