Variation in the Concentration of Ellagitannins and cis- and trans-ß-Methyl-γ-Octalactone Extracted From Oak Wood (Quercus robur L., Quercus petraea Liebl.) Under Model Wine Cask Conditions

Abstract

In this study we examine the chemical composition in ellagitannins and oak lactones of 12% ethanol solutions placed in model casks for 200 days, in contact with disks of unheated oak wood. The correlations observed between the wood anatomy and the concentration of extractives are not able to explain the enormous variability found among the samples. The results suggest that the effect of wood anatomy on the extraction of tannins and lactones is less important than the intrinsic differences in the levels of these extractives found in the same wood tissue of different trees and between the two species Quercus robur and Quercus petraea. Species is suggested as a better indicator than wood ring width ("grain") of the chemical cask effects which may affect wine and spirit quality.