Phenolic Transfer and Dissolved-Oxygen Dynamics in Different White Wines Treated with Two Quercus alba Wood Samples with Contrasting Grain Widths.

American oak is widely used in enology, but its interactions with white wine and the role of wood properties remain poorly understood. In this study, oxygen dynamics and changes in the phenolic composition of wines made from the Verdejo, Albillo, Rufete, and Puesta en Cruz varieties were evaluated over 35 days of contact with toasted pieces from two Quercus alba wood samples with contrasting grain widths. Untreated control wines and a model wine treated separately with each wood were also included. Wood density and impregnation were determined, dissolved-oxygen partial pressure was monitored noninvasively, and routine enological parameters, spectrophotometric indices, and low-molecular-weight phenolic compounds were analyzed in the final wines. Contact with wood modified the net dissolved-oxygen profiles, although the relative effects of the two contrasting wood samples depended on the wine matrix. The fine-grain wood tested showed greater impregnation and generally produced higher phenolic indices, larger changes in color, and higher concentrations of several wood-derived compounds. Overall, the results show that the properties of the two wood samples and wine composition jointly shape the response of white wines to oak contact.