Abstract
High-gravity brewing improves production efficiency but can reduce fermentation performance when yeast cells experience osmotic stress, nutrient limitation, and increasing ethanol pressure. This study examines high-gravity brewing optimization through controlled yeast nutrient supplementation. Fermentations were conducted using elevated wort gravity under fixed temperature, pitching rate, oxygenation, and yeast strain conditions. Assimilable nitrogen, vitamins, minerals, sugar utilization, yeast viability, ethanol yield, attenuation, glycerol formation, pH change, and fermentation duration were monitored. The results show that balanced nutrient supplementation improved yeast vitality, accelerated maltose and maltotriose uptake, and increased attenuation stability under high-gravity conditions. Insufficient supplementation caused sluggish fermentation and higher residual extract, while excessive nutrient addition increased higher alcohol formation and altered flavour balance. The study demonstrates that nutrient optimization must match yeast metabolic demand rather than simply increase nutrient concentration. Overall, controlled supplementation improves fermentation reliability, ethanol yield, and process consistency in high-gravity brewing.