Pulsed Electric Fields as an Alternative to Reduce SO2 in Oenology: A Comparative Case Study at Pilot Scale

Pulsed Electric Fields (PEF) offer significant potential to enhance energy efficiency and reduce reliance on SO2 and other chemical preservatives, aligning with current sustainability and health demands. This work evaluates PEF industrial viability for wine stabilisation through a multidisciplinary pilot-scale approach (108 L/h). A sulfur-free comparative trial evaluated four sequential bipolar PEF treatments (20–23 kV/cm; 19–34 kJ/kg) against stabilisation with a commercial chitosan–glucan complex. PEF caused significant effects on microbial kinetics: B. bruxellensis was successfully maintained below the detection limit and lactic acid bacteria (LAB) were undetected by the end of the trial. Standard oenological parameters showed no relevant changes, except for lactic acid dynamics, corroborating LAB knockdown. Regarding metal ion migration into the food matrix, Fe, Ni, and Cr were assessed. No significant variations were found for Fe and Ni compared to the control group; all elements presented residual concentrations compatible with international regulatory guidelines. Sensory analysis revealed that PEF-treated wines exhibited lower perceived bitterness and higher colour intensity, driven by B. bruxellensis proliferation in control wines. In total, 75% of panellists preferred PEF wines. OPEX analysis demonstrates industrial competitiveness for medium-to-large scale, reducing consumable costs over 10-fold (0.6064 vs. 6.50 €/hL), excluding initial CAPEX. These findings validate multi-stage, pilot-scale PEF as a competitive and electrochemically safe technology to transition toward sustainable reduced-SO2 or SO2-free winemaking.