The Effect of Toasted and Untoasted Oak Chips and Granular Oak Additions to Red Must (2016)

This study examines the impact of toasted and untoasted granular oak additions to Petit Verdot must. Petit Verdot grapes were sourced identically and processed identically into 4 separate fermentation vessels, one without oak additions, one with untoasted oak chip additions, one with toasted oak chip additions, and one with Xtrachene medium toast French granular oak additions. All other treatments were kept the same between wines. The Xtrachene granular oak exhibited the greatest increase in color intensity, tannin content, and polymeric anthocyanins (suggesting more color stability). Color was only slightly improved by oak chips. Untoasted oak chips and Xtrachene toasted granular oak exhibited an increase in caftaric acid, catechin, epicatechin, and gallic acid. Oak consistently lowered caffeic acid, although the numbers are very small. Anthocyanin extraction was not enhanced by oak, and was even lowered by toasted oak chips. In general, oak saw increases in color, catechin, epicatechin, and tannin, with granular oak resulting in the largest increases. In general, people preferred the control wine. The second-most preferred and least-most preferred wines were made with Granular Oak. No strong trends were found for the descriptors used in this study. The Granular Oak treatment seemed to increase Bitterness, Fruit Intensity, and Astringency more than the other treatments. Toasted Chips appeared to increase Fruit Intensity, along with Granular Oak. However, these tendencies were weak. Wines made with Granular Oak were often described as being oaky or smoky.

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