Veraison
Veraison is a key phenological stage in the annual growth cycle of the grapevine, marking the onset of ripening in grape berries. From a wine perspective, veraison represents the transition from berry growth to berry maturation and signals the beginning of the period in which grape composition becomes increasingly relevant to wine style, balance and quality.[1]
Definition and timing
Veraison refers to the point at which grape berries soften and begin to change colour. In red grape varieties, berries shift from green to red, purple or blue as anthocyanins accumulate in the skins. In white varieties, berries become more translucent and yellowish. Veraison typically occurs in mid to late summer, following fruit set and preceding full ripeness.[2]
The timing of veraison varies according to grape variety, climate, site conditions and seasonal weather patterns. It is often used as a reference point for predicting harvest dates.
Physiological changes
At veraison, the berry undergoes major physiological and biochemical changes. Berry growth driven by cell division and enlargement largely ceases, and metabolic activity shifts towards ripening processes. Sugar accumulation accelerates as glucose and fructose are transported from the leaves to the berries, while organic acids, particularly malic acid, begin to decline through respiration.[3]
Concurrently, phenolic compounds such as anthocyanins and tannins develop, influencing colour, structure and ageing potential in red wines. Aroma precursors also increase during this phase, shaping varietal expression.[4]
Viticultural significance
From a vineyard management perspective, veraison is a critical reference stage. Decisions regarding leaf removal, irrigation, crop thinning and disease management are often adjusted at or around veraison to influence ripening rate and grape composition. The uniformity of veraison across a vineyard can affect harvest decisions and final wine consistency.[5]
Veraison is also closely linked to climate sensitivity. Warm temperatures tend to advance veraison, while cool or cloudy conditions can delay it, with implications for flavour development and balance.
Climate change considerations
Research has shown that veraison has been occurring progressively earlier in many wine regions as a result of climate change. Earlier veraison can lead to earlier harvests, higher potential alcohol and altered acid profiles, challenging traditional wine styles and prompting adaptations in both viticulture and winemaking.[6]
Economic and winemaking implications
The timing of veraison influences harvest planning, labour allocation and winery logistics. In regions producing multiple wine styles, the progression of veraison across different varieties helps structure production schedules. From a wine quality perspective, the period between veraison and harvest is often considered the most critical window for shaping the balance between sugar, acidity, phenolics and aroma compounds.[7]
See also
References
- ↑ Jancis Robinson, Oxford Companion to Wine, Oxford University Press, 17 Sept. 2015. ISBN 9780198705383.
- ↑ A. J. Winkler, James A. Cook, William Mark Kliewer, Lloyd A. Lider, General Viticulture, University of California Press, December 13, 1974. ISBN 9780520025912.
- ↑ Pascal Ribéreau-Gayon, Yves Glories, Alain Maujean, Denis Dubourdieu, & 1 more, Handbook of Enology, Volume 2: The Chemistry of Wine - Stabilization and Treatments, Wiley, 31 Mar. 2006. ISBN 9780470010372.
- ↑ Andrew L. Waterhouse, Understanding Wine Chemistry, Wiley, 19 Aug. 2016. ISBN 9781118627808.
- ↑ Markus Keller, The Science of Grapevines: Anatomy and Physiology, Academic Press Inc, 19 Jan. 2015. ISBN 9780124199873.
- ↑ Jones et al., Climate Change and Global Wine Quality, Wiley, 2012, ISBN 9781118450048.
- ↑ PhD Jackson, Ronald S., Wine Science: Principles and Applications, Academic Press Inc, 14 April 2020. ISBN 9780128161180.