Millerandage
Millerandage is a viticultural phenomenon characterised by irregular fruit set within a grape cluster, resulting in berries of markedly different sizes and levels of maturity. Affected bunches typically contain a mixture of normal, seeded berries and small, underdeveloped, seedless berries, often referred to colloquially as shot berries. The condition occurs during flowering and early berry development and can significantly influence yield, ripening dynamics, and wine style.[1]
Definition and distinction
Millerandage is distinct from coulure, although the two are often discussed together. While coulure involves the failure of flowers to set fruit at all, millerandage involves incomplete or abnormal fertilisation, leading to partial berry development rather than flower drop.[2]
The presence of both phenomena in the same vineyard or season is common, particularly under adverse flowering conditions.
Causes
The primary causes of millerandage are disruptions to normal flowering and fertilisation, most often linked to weather conditions. Cool, cloudy, or wet weather during flowering can interfere with pollen viability and fertilisation, increasing the likelihood of uneven berry development.[3]
Other contributing factors include:
- Nutrient imbalances, particularly boron deficiency
- Reduced carbohydrate availability during flowering
- Excessive vegetative growth and shading
- Varietal sensitivity to poor flowering conditions[4]
Certain grape varieties are consistently more prone to millerandage than others, reflecting differences in floral biology and fertilisation efficiency.[5]
Viticultural implications
From a yield perspective, millerandage generally reduces overall crop weight due to the high proportion of small, seedless berries. However, its qualitative impact is more nuanced. The smaller berries have a higher skin-to-juice ratio and often reach higher sugar and phenolic concentrations than fully developed berries.[6]
This heterogeneity within the cluster can complicate harvest timing, as fully developed berries and shot berries may not reach optimal ripeness simultaneously.
Impact on wine style
In red wines, moderate millerandage is sometimes considered beneficial, as the increased proportion of skins can enhance colour, tannin concentration, and aromatic intensity. In white wines, however, uneven ripening may result in imbalances between acidity and flavour development if harvest timing is not carefully managed.[7]
The sensory impact of millerandage therefore depends on grape variety, wine style, and the degree of berry size variation present in the crop.
Management considerations
There is no direct remedy for millerandage once it has occurred, but vineyard practices can influence its incidence. Balanced vine vigour, adequate nutrient availability, and canopy management that promotes favourable microclimatic conditions during flowering can reduce risk.[8]
In regions experiencing increasing climatic variability, millerandage is expected to remain a recurrent challenge, particularly in cool-climate and marginal viticultural zones.[9]
Economic and cultural aspects
From an economic standpoint, millerandage introduces yield uncertainty and may increase production costs due to lower volumes and more complex harvest decisions. Nevertheless, in some premium contexts, wines produced from millerandage-affected fruit are valued for their concentration and structural intensity.[10]
Perceptions of millerandage thus vary between regions and market segments, reflecting broader attitudes toward yield, quality, and typicity.[11]
See also
References
- ↑ Jancis Robinson, Oxford Companion to Wine, Oxford University Press, 17 Sept. 2015. ISBN 9780198705383.
- ↑ PhD Jackson, Ronald S., Wine Science: Principles and Applications, Academic Press Inc, 14 April 2020. ISBN 9780128161180.
- ↑ Markus Keller, The Science of Grapevines: Anatomy and Physiology, Academic Press Inc, 19 Jan. 2015. ISBN 9780124199873.
- ↑ Michael G. Mullins, Alain Bouquet, Larry E. Williams, & 0 more, Biology of the Grapevine, Cambridge University Press, July 30, 2007. ISBN 9780521038676.
- ↑ Jancis Robinson, Jose Vouillamoz, Julia Harding, & 0 more, Wine Grapes: A Complete Guide to 1,368 Vine Varieties, Including Their Origins and Flavours, Ecco, 1 Nov. 2012. ISBN 9780062206367.
- ↑ 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.
- ↑ Smart & Robinson, Sunlight into Wine, Winetitles, 1991, ISBN 9781875130033.
- ↑ Jones et al., Climate Change and Global Wine Quality, Wiley, 2012, ISBN 9781118450048.
- ↑ Anderson & Pinilla, Wine Globalization, Cambridge University Press, 2018, ISBN 9781108445687.
- ↑ Charters, Wine and Society, Elsevier, 2006, ISBN 9780750669788.