The effect of cask charring on Scotch whisky maturation

Summary The developing chemical composition and aroma attributes of whisky distillates maturing in uncharred and charred American oak casks were compared at intervals over a total maturation period of 3 years. Chemical variables were selected to encompass a wide range considered to contribute to the flavour of maturing distillate. Descriptive sensory analysis was used to generate detailed sensory profiles which were very different for the charred and uncharred cask samples throughout the maturation period. the charred cask samples were rated significantly higher for terms characteristic of mature distillates and significantly lower for terms characteristic of immature distillates. There were significant differences in syringaldehyde, conifer-aldehyde, sinapaldehyde, vanillic acid, total phenols and absorbance between the charred and uncharred cask samples but these differences did not completely account for the changes in sensory characteristics.