Abstract
Belgian-style strong ales require careful yeast nutrient management because high wort gravity, increasing ethanol concentration, and complex sugar composition can reduce fermentation attenuation. This study examines how yeast nutrient balance affects attenuation in Belgian-style strong ale fermentation. Controlled fermentations were conducted using high-gravity wort under fixed pitching rate, oxygenation, temperature, and yeast strain conditions. Free amino nitrogen, mineral availability, vitamin contribution, sugar utilization, ethanol formation, yeast viability, pH reduction, glycerol production, and residual extract were monitored. The results show that balanced nutrient supplementation improved maltose and maltotriose uptake, supported yeast vitality, and increased attenuation consistency. Nutrient deficiency caused sluggish fermentation and higher residual sweetness, while excessive supplementation increased higher alcohol formation and altered flavour balance. The study demonstrates that attenuation in strong ales depends on matching nutrient supply with yeast metabolic demand. Proper nutrient control supports stronger fermentation completion, cleaner flavour development, and more consistent Belgian-style strong ale production.