High-Gravity Brewing, Yeast Strain Selection, and Glucose Oxidase Effects on the Quality of Nonalcoholic Beer

Producing high-quality nonalcoholic beer (NAB) requires precise management of ethanol levels while maintaining desirable sensory properties. This study investigated the influence of high-gravity brewing (HGB), yeast strain selection, and glucose oxidase (commercially sold by dsm-firmenich as TasteZyme G (TG)) treatment on NAB quality. Fermentations were performed using two maltose-negative<i>Saccharomyces cerevisiae</i>strains (LalBrew LoNa and SafBrew LA-01) and an arrested fermentation with SafLager W-34/70 (<i>Saccharomyces pastorianus</i>) in 16.2-16.9% w/w HGB wort. Key parameters, including fermentation kinetics, ethanol formation, residual sugars, gluconic acid accumulation, volatile aroma compounds, and sensory characteristics (descriptive analyses and triangle tests), were assessed. LA-01 and LoNa produced beers with ethanol concentrations up to 1.53% v/v prior to dilution, while W-34/70 reached 0.78% v/v. TG treatment effectively decreased the glucose content and increased gluconic acid levels; however, after dilution, the impact on most NABs was minimal. Notably, TG addition reduced phenolic off-flavors associated with the POF⁺ LA-01 strain, while the effect on other products was not as clear. Sensory analysis revealed that NABs from maltose-negative strains exhibited a clean, balanced flavor profile, whereas W-34/70 samples were perceived as sweeter and more worty. The combined approach of HGB, strategic yeast selection, and enzymatic glucose modulation enabled precise control over ethanol, residual sugar, and aroma composition. These findings demonstrate that integrating fermentation management with targeted enzymatic treatment offers a practical strategy for producing NABs with low ethanol (<0.5% v/v), moderated sweetness, and enhanced aromatic complexity, supporting industrial-scale applications.