Abstract
High-gravity wort fermentation increases brewing productivity but places strong osmotic and ethanol stress on Saccharomyces cerevisiae, affecting fermentation speed, sugar uptake, and final beer quality. This study examines the fermentation kinetics of S. cerevisiae under high-gravity wort conditions using controlled laboratory-scale brewing trials. Wort with elevated extract concentration was fermented under fixed pitching rate, oxygenation, temperature, and nutrient conditions. Glucose, maltose, maltotriose, ethanol formation, yeast growth, glycerol production, attenuation, pH reduction, and fermentation time were monitored. The results show that high-gravity wort extended the initial lag phase and slowed maltotriose consumption compared with standard wort. However, sufficient oxygenation and nutrient balance improved yeast adaptation, ethanol yield, and attenuation stability. The study demonstrates that high-gravity brewing efficiency depends on matching wort strength with yeast physiological tolerance. Overall, the findings support improved control of fermentation performance in dense wort brewing systems.