Abstract
Packaging can cause flavour drift in beer through oxygen exposure, carbonation changes, yeast activity, pressure variation, and storage temperature effects. This study compares packaging-induced flavour drift in bottle-conditioned and kegged beers. Beer samples were packaged using controlled dissolved oxygen levels, carbonation targets, yeast presence, and storage conditions. Ester retention, aldehyde formation, hop aroma loss, carbonation stability, dissolved oxygen, pH, turbidity, bitterness perception, and sensory freshness were monitored over storage. The results show that bottle-conditioned beers retained some aroma complexity due to residual yeast activity but showed higher sediment and flavour variation when temperature control was poor. Kegged beers showed stronger flavour consistency but were more sensitive to oxygen pickup during filling and dispensing. Elevated storage temperature increased stale notes in both formats. The study demonstrates that packaging format influences flavour stability through different mechanisms. Proper oxygen control, carbonation management, and storage conditions are essential for maintaining beer quality after packaging.