Estimation of beer stability by sulphur dioxide and polyphenol determination. Evaluation of a Laccase-Sonogel-Carbon biosensor

► A critical revision of methodologies widely employed in beer analysis is presented. ► The role of SO2 in the delay of the formation of free radicals in beers is highlighted. ► The interaction between SO2 and some polyphenols retards the loss of SO2 and hence beer ageing. ► Polyphenols have an indirect and positive role in beer ageing. ► Laccase-Sonogel-Carbon biosensor is proposed to determine polyphenols in beers.