Identification and characterization of a native Brazilian yeast strain with enhanced sensory attributes for craft beer production

Abstract The brewing industry is evolving with an increasing demand for quality improvement and unique flavour profiles. This study aimed to identify and characterise novel yeast strains for craft beer production, focusing on the biodiversity of native Brazilian yeasts. Yeasts were collected from 13 production points in a microbrewery, analysed morphologically, and characterised through Internal Transcribed Spacer (ITS) rDNA sequencing, revealing the presence of both Saccharomyces and non-Saccharomyces species. Among the isolates, Wickerhamomyces anomalus emerged as a dominant non-Saccharomyces species, followed by Saccharomyces cerevisiae. A total of 119 isolates were identified, grouped into eight Saccharomycetales species, and classified into pre- and post-fermentation genetic categories. Five S. cerevisiae strains were selected for fermentation trials under varying temperatures and malt extract concentrations. These strains were tested in small-scale beer production and evaluated for fermentation efficiency, volatile compound production, and sensory attributes. Strain GP2 exhibited superior fermentation performance, high ethanol yield, and an enhanced ester profile, contributing to a complex, fruity aroma. Gene expression analysis via qPCR revealed metabolic shifts in GP2, particularly in genes related to sugar metabolism, ethanol production, and aroma formation (PDC1, ACS2, ALD6, and ADH1). These findings highlight the potential of native yeast strains to enhance brewing processes, optimise flavour profiles, and support the development of microbial resources for craft breweries aiming to produce distinctive, high-quality beers.