Wood and Mint Aroma Interactions During Spirit Oak Cask Maturation: A Sensory Case Study

The aroma of fine matured spirits is typically complex, resulting from numerous reactions occurring during the production process and some developing during maturation in oak casks. The refreshing sensation brought by mint notes was often expected, even after years of maturation. The main challenge lies in achieving an aromatic balance characterised by the seamless integration of woody aromas while maintaining the initial distillate's freshness. The present study examines the sensory effects associated with the interactions between wood, mint and cold sensations in spirits. Nine spirit model solutions were prepared, representing different combinations of terpene ketones (imparting mint aroma) and wood compounds, each at three concentration levels. The quantitative composition of mint compounds simulated varying degrees of mintiness in the distillate (low, medium and high), while the concentrations of wood compounds mimicked three maturation periods (short, intermediate and long term) in wooden casks. Samples were sensorily analysed by discriminative (triangle test) and rate-all-that-apply (RATA) methodologies. An increase in woody intensity was notably perceived in samples with a low-mint profile and containing wood compounds associated with medium and long-term maturation. However, no significant sensory differences were observed in mint and cold perception between model solutions regardless of the simulated maturation conditions, indicating a limited influence of the studied wood compounds on the sensation of freshness in spirits due to competitive perceptual interactions with terpene ketones.