How ultraviolet rays can improve wine

Want to increase grape quality in your vineyard? The answer may lie in ultraviolet rays. Research conducted by the University of Pisa indicates that the targeted use of UV-C radiation during the ripening phase can positively influence the final quality of grapes without negatively affecting vineyard productivity.

The use of UV-C rays is not entirely new in viticulture. In recent years, several trials in Spain had already tested their effectiveness in controlling the main fungal diseases of the vine, with the aim of reducing reliance on plant protection products, attracting interest in the United Kingdom as well.

The trial in Bolgheri

Published in the scientific journal Plants, the study was carried out in the Cabernet Sauvignon vineyards of Tenuta dell’Ornellaia. Researchers assessed the effects of UV-C light applications directly in the field, intervening in a targeted manner during the final stage of the vegetative cycle. The objective was to verify whether additional, carefully timed treatments could influence grape composition at harvest.

The positive effects

The results suggest a potential improvement in the qualitative profile, opening up new prospects for a form of viticulture increasingly oriented towards sustainability. In particular, an increase in the concentration of anthocyanins and flavonols was observed in the treated clusters—compounds associated with the intensity and stability of colour in red wines—along with a rise in certain aromatic molecules.

“We knew that UV light can stimulate the synthesis of molecules linked to wine quality, but these effects had mainly been observed under laboratory conditions,” explains Claudio D’Onofrio, Professor of Viticulture at the University of Pisa and coordinator of the research. “This work demonstrates that even in the vineyard it is possible to achieve greater colour intensity and enhanced aromas without penalising yields.”

According to D’Onofrio, UV-C light could become an additional tool for improving grape quality while simultaneously reducing the environmental impact of viticulture. “A highly topical issue for the sector, which is called upon to combine sustainability, innovation and quality in an increasingly complex climatic context.”