On-vine grape drying with pruning of the fruit branch can help producing high quality peppery red wines
Abstract
Rotundone is a grape derived aroma compound responsible for peppery notes discovered in 2008 in red wines. A recent study showed the link existing within the same block between grapevine water status and rotundone concentration in wines with higher levels recorded in grapes from vines experiencing low water deficit. In most cases, especially in vineyards under oceanic climatic influence, it makes problematic to produce red wines combining both superior concentration in peppery compounds and phenolic richness. An experiment was conducted in 2013 and 2014 to study the impact of on-vine grape drying with pruning of the fruit branch – a technique which consists in sectioning pruning canes 2 to 3 weeks prior to harvest on a Guyot-trained vineyard – on rotundone in red wines made from Duras. The pruning of the fruit branch slightly slowed down rotundone accumulation in 2013 and didn’t impact final concentrations in 2014. As the sap flow is completely interrupted, these observations show that rotundone is synthetized in berries, not in leaves and then redistributed to the fruits. The viticultural system combining five irrigations of 14 mm followed by on-vine grape drying with pruning of the fruit branch was very effective in improving most of the qualitative parameters of the harvest (potential alcohol, TPI, anthocyanins and skin to juice ratio) while increasing rotundone concentration by 45%.
Issue: GiESCO 2015
Type: Extended abstract
Authors
1 Institut Français de la Vigne et du Vin – Pôle Sud-Ouest, V’innopôle, BP22, 81310 LISLE SUR TARN – France
2 Institut Français de la Vigne et du Vin – Pôle Sud-Ouest, Château de Mons, 32100 CAUSSENS – France
3 Australian Wine Research Institute, PO Box 197, GLEN OSMOND SA 5064 – Australia
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Keywords
rotundone, peppery aroma, on-vine grape drying, wine quality, phenolic compounds