Orange melomel with different compositions and yeast strains – evaluation of fermentation kinetics and physico-chemistry parameters

Abstract

This study evaluated the performance of Saccharomyces yeast strains in fermenting traditional mead, meads with varying proportions of orange juice, and a formulation with orange juice and peels. Experiments at 25–30 °C used strains 71B-1122 and ICV-D47 (Lalvin) and Montrachet (Red Star). Fermentation kinetics were tracked via CO₂ release, and final products were analyzed for total reducing sugars (TRS), ethanol, pH, acidity, dry matter, and density. Tukey’s test was applied for statistical comparison. Lalvin 71B-1122 was later selected for batch fermentations with direct aeration and stepwise nutrient addition. Volatile acidity was also measured. Flask-scale experiments showed no significant differences in fermentation kinetics among strains. Musts with orange juice completed fermentation in 160–180 h, while honey-only musts did not. TRS conversion was higher in orange juice formulations (0.38–0.44), with similar dry matter and density. Orange juice musts had higher pH (3.51–3.73) and acidity (72.6–113.8 meq/L) than pure mead (pH 3.05–3.25; 58.2–60.2 meq/L), due to organic acids’ buffering capacity. Larger batch fermentations yielded beverages with higher ethanol content (10.5–12.6% v/v), yield (71.2–89.0%), and efficiency (82.8–96.4%), confirming the beneficial effect of optimized nutrient management and aeration on fermentation performance.