Contribution of Grapes and Oak Wood Barrels to Pyrrole Contents in Chardonnay Wines: The Influence of Several Cooperage Parameters.

The influence of some enological parameters on pyrrole concentrations in Chardonnay wines was studied. First, a quantitative method to assay five pyrroles was optimized and applied to determine their content in wines produced in different containers. All pyrroles were observed in wines aged in a stainless-steel tank, which indicated that they have a varietal or fermentative origin. However, their concentrations were significantly higher in wines made in new barrels than in older barrels or in a stainless-steel tank, so oak wood may largely contribute during the winemaking process. A quantitative method to assay pyrroles in oak wood extract was also developed to study the influence of several cooperage parameters such as different types of traditional toasting, as well as the temperature and the time of toasting. Significant differences were observed on pyrrole concentrations in oak wood extracts according to these different cooperage parameters. These findings bring new perspectives to the monitoring of winemaking and the aging of Chardonnay wines.