Abstract
Bottle-conditioned beers continue to change after packaging because residual yeast supports carbonation but also influences sedimentation, turbidity, clarification, and flavour stability. This study examines yeast flocculation dynamics and clarification efficiency in bottle-conditioned beers. Beer samples were bottle-conditioned using selected yeast strains with different flocculation behaviours under controlled priming sugar, yeast dose, oxygen exposure, and storage temperature. Yeast sedimentation rate, floc size, turbidity, carbonation pressure, residual sugar, pH, cell viability, sensory quality, and clarification efficiency were measured. The results show that highly flocculent yeast improved clarification speed and reduced turbidity, but excessive sediment compaction affected visual appearance during handling. Low-flocculent yeast maintained longer suspension, improving conditioning activity but delaying clarification. Moderate flocculation produced the best balance between carbonation completion and visual clarity. The study demonstrates that bottle-conditioned beer quality depends on matching yeast flocculation behaviour with conditioning duration, storage condition, and desired product appearance.