Whole Cluster Inclusion in Petit Verdot Fermentations (2017)

This study examines the impact of whole cluster fermentation versus more traditional fermentation techniques in Petit Verdot winemaking. Petit Verdot grapes were harvested and processed into two T Bins. One treatment was completely destemmed, whereas the other treatment was 100% whole cluster inclusion. The 0% inclusion treatment was punched down, whereas the whole cluster treatment was stomped for punchdowns. When the 0% treatment reached approximately 8 Brix, the fermenting wine was delestaged and the pomace was stomped, and the wine was then racked back into the stomped pomace. Wine was pressed 16 days after processing. Juice and wine chemistry were very similar between treatments, except TA was slightly lower in the whole cluster treatment. Color was slightly increased, and many phenolic compounds were increased by whole cluster inclusion. Although anthocyanin was lower from whole cluster treatment, polymeric anthocyanins were increased. Overall, these wines were not found to be significantly different. There may have been a slight preference for the whole cluster wine. The whole cluster wine tended to score higher in Bitterness, Astringency, and Fruit Intensity. The whole cluster inclusion treatment had the clusters stomped during T Bin filling, which may have reduced some of the more estery characteristics often seen in whole cluster winemaking. Thus, these results may be more in line with what would be expected with a stem inclusion wine, rather than a purely whole cluster wine. This study suggests that whole cluster inclusion may be a useful method for creating a Petit Verdot which could serve as a valuable blending component, but more studies on whole cluster Petit Verdot are needed to determine whether any strong trends can be seen between treatments over time.

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