Abstract
Barrel-aged beer maturation involves gradual interaction between beer, wood, oxygen, and resident microflora, which changes phenolic composition and sensory character over time. This study evaluates phenolic compound evolution during barrel-aged beer maturation. Beer samples were matured in wooden barrels under controlled cellar conditions and analyzed at defined ageing intervals. Total phenolic content, tannin extraction, vanillin-related compounds, colour intensity, dissolved oxygen, pH, turbidity, antioxidant activity, and sensory descriptors were measured. The results show that phenolic concentration increased during early barrel contact because of wood extraction, followed by gradual stabilization through oxidation, polymerization, and precipitation. Moderate phenolic evolution improved body, dryness, colour depth, and mature flavour complexity. Excessive extraction produced astringency and harsh woody notes. Oxygen ingress strongly influenced the pace of phenolic transformation and beer ageing character. The study demonstrates that barrel maturation quality depends on balancing wood contact duration, oxygen exposure, and phenolic stability.