Abstract
Wort aeration is essential for yeast growth because oxygen supports sterol and unsaturated fatty acid synthesis, which affects membrane strength, fermentation activity, and batch consistency. This study evaluates wort aeration strategy and its effect on yeast growth consistency. Brewing trials were conducted using different aeration levels and timing approaches while maintaining constant wort gravity, yeast strain, pitching rate, and fermentation temperature. Dissolved oxygen, yeast cell growth, viability, sugar uptake, ethanol production, attenuation, pH decline, fermentation duration, and flavour by-product formation were measured. The results show that insufficient aeration reduced yeast growth and increased fermentation variability, while excessive oxygen exposure promoted oxidative stress and altered flavour precursor development. Controlled aeration before pitching produced more consistent yeast propagation and stable attenuation. The study demonstrates that wort aeration should be optimized as a process-control variable rather than applied as a fixed routine step. This improves yeast performance and fermentation reliability.