Exploring new applications of toasted chestnut shells as an oak alternative in distilled spirit aging

This study investigated the potential of toasted chestnut shells as a novel and cost-effective material for aging distilled spirits. Results showed that aging whiskey with toasted chestnut shell chips moderately increased its acidity (0.14-0.18 g/L) and total phenolic content (48.28-109.58 mg/L), while imparting a color ranging from yellowish to light amber. HS-SPME-GC-MS, HS-GC-IMS, E-nose, and sensory evaluation analyses revealed the distinct aroma characteristics of whiskeys aged with toasted chestnut shell chips. Compared to whiskeys aged with toasted oak, which contained abundant ethyl esters and exhibited an obvious fruity aroma, aging whiskeys with toasted chestnut shell chips significantly increased the level of aldehydes while decreasing the levels of ethyl esters and acetate esters. 2-methyl butanal was identified as the key aroma compound that accounts for the pronounced roasted/smoky aroma in these whiskeys. This study provides valuable insights into the conversion of agro-industrial by-product into new oak alternatives in the oenological field.