Effect of pre-fermentative cold soaking and use of different enzymes on the chemical and sensory properties of Catarratto wines

The wine industry acknowledges that early harvested grapes or those with uneven ripeness often result in wines with an “unripe fruit” mouthfeel. However, the compounds causing these sensory flaws and the best winemaking techniques to address them remain unclear. This study examines the effects of pre-fermentative cold soaking (PCS) and enzyme addition during fermentation on the chemical composition and sensory properties of Catarratto wine, a variety commonly linked to these issues. The hypothesis suggests that grape polysaccharides released during PCS and yeast polysaccharides from fermentation contribute to producing smoother wines. Two winemaking approaches were tested: traditional non-PCS (NPCS) and PCS with 48-hour skin contact at 4°C. Each group included a control and four enzyme treatments: three pectolytic enzymes and a β-glucanase enzyme. Results showed PCS significantly increased grape polysaccharide release, doubling total colloids and enhancing the wine’s aromatic complexity. Enzyme treatments increased yeast-derived polysaccharides, with β-glucanase having the greatest impact, raising mannose levels. The addition of enzymes at the beginning of the alcoholic fermentation had no impact on fermentation kinetics but boosted yeast polysaccharide levels. Sensory analysis revealed enzyme-treated wines reduced the “unripe fruit” perception and improved smoothness. This research demonstrates for the first time the potential of PCS and enzymes to enhance the quality of Catarratto wines made from early harvested grapes.