Process for partial or total dealcoholization of wine using a post-fermentation microbiological technique

The dealcoholized wine sector is experiencing strong market growth, driven by increasing consumer demand. Current oenological practices allowed for wine dealcoholization by the OIV Code of Oenological Practices are based on physical processes. The Robert-Jean de Vogüé Research Center has developed an innovative, microbiology-driven post-fermentation method for wine dealcoholization. This process reduces or eliminates alcohol content while preserving the wine’s essential organoleptic properties. Unlike existing techniques that can degrade quality, generate waste, or require additives, this method aims to produce a dealcoholized wine with a flavor profile closely resembling the original, achieved without exogenous water or external inputs. The process involves a combination of membrane separation and microbiological techniques. Initially, the wine is separated into two fractions using a membrane: a concentrated fraction (retentate) containing all the wine’s essential components, and a permeate primarily composed of water and ethanol. The ethanol in the permeate is then metabolized by yeasts, specifically Saccharomyces cerevisiae, under aerobic conditions. These yeasts are previously cultured in a nutrient-rich medium, and controlled conditions are applied to initiate the diauxic shift. This shift involves the transition of yeast metabolism from fermentation to respiration once the primary sugar source is depleted, allowing the yeasts to consume ethanol as a secondary substrate. Subsequently, the yeasts are added to the permeate, where they metabolize the ethanol into carbon dioxide and water. Optionally, the retentate can undergo diafiltration with the dealcoholized permeate to further reduce its alcohol content. Finally, the retentate and dealcoholized permeate are recombined to produce a wine with significantly reduced alcohol content. This method ensures the preservation of the wine’s aromatic and taste qualities, making it suitable for producing high-quality dealcoholized wines. The process is versatile, environmentally friendly, and compatible with various types of wines.