Sustainability of the Alcoholic Fermentation in Catarratto and Inzolia Grapes (V. vinifera L.)

Improving environmental sustainability in winemaking involves reducing the energy required for thermal control during alcoholic fermentation, while preserving the fruity character of wines. This study evaluated two white grape cultivars (Catarratto and Inzolia), fermented at two temperatures (15 °C and 20 °C) using two Saccharomyces cerevisiae strains (SafOeno™ SC22 and SafOeno™ BC S103). Fermentation at 20 °C led to significantly faster sugar consumption, concluding 2.2 days earlier than fermentations at 15 °C. No major differences in fermentation kinetics were observed between the yeast strains. Volatile ester concentrations were generally higher at 15 °C, particularly with BC S103, although varietal effects were evident. Acetaldehyde levels were slightly higher at 20 °C (below 10%), particularly with BC S103, while acetoin was more abundant at 15 °C. However, all carbonyl compounds with potential odour impact remained below sensory thresholds. Sensory analysis indicated that the choice of yeast strain had a greater influence on aroma than fermentation temperature, suggesting that fermenting at 20 °C does not compromise wine quality. A cost analysis highlighted that fermentation at 20 °C significantly lowers production costs compared to 15 °C, mainly due to reduced energy and labor inputs. The lowest estimated cost was observed for BC S103 at 20 °C (5.30 € hL⁻¹), indicating that moderate fermentation temperatures combined with low-nutrient yeast strains offer a cost-effective and sustainable strategy for white wine production.