Dynamic changes of flavor characterization of lager beer during barrel aging process based on untargeted volatilomics

Oak barrel aging induces complex, time-dependent transformations in beer flavor. This study systematically characterized these changes through a 300-day aging experiment integrating quantitative sensory analysis, physicochemical monitoring, and HS-SPME-GC–MS-based volatile metabolomics. Barrel aging introduced distinct coconut and vanillin notes, with extended aging further intensifying woody, sweet, and caramel characteristics, while wine-like notes remained stable. Volatile profiling identified 162 significantly differential metabolites across 12 chemical classes, including esters, aromatic compounds, ketones, and heterocyclic compounds. Mantel correlation analysis revealed that three wood-derived volatiles—( Z )-oak-lactone, ethyl 2-furoate, and (2,2-diethoxyethyl) benzene—were strongly correlated with aging time (|r| > 0.8) and served as potential biomarkers. Notably, ( Z )-oak-lactone was quantitatively linked to both “woody” and “sweet” odor notes ( r > 0.89). These findings establish a predictive chemical-sensory framework for understanding flavor development during barrel aging. • 300-day study maps dynamic sensory-chemical changes in barrel-aged beer. • Integrated sensory, physicochemical, and volatilomics analyses performed. • ( Z )-Oak-lactone, ethyl 2-furoate, and (2,2-diethoxyethyl)benzene are aging biomarkers. • Strong links established between specific volatile compounds and sensory attributes. • Findings provide scientific basis for predicting beer flavor development.