Description of the temporal dynamics in microbial community composition and beer chemistry in sour beer production via barrel ageing of finished beers

Currently, there is a strong interest in barrel ageing of finished, conventionally fermented beers, as novel way to produce sour beers with rich and complex flavour profile. The production process, however, remains largely process trial error, often resulting profit losses inconsistency quality. To improve product quality consistency, better understanding the interactions between microorganisms, wood maturing beer needed. aim this study was describe temporal dynamics microbial community composition, chemistry sensory characteristics during three that differed parameters like alcohol content bitterness. Beers were matured for 38 weeks new (two types wood) used (one type oak barrels. Beer samples taken at start maturation after 2, 12 weeks. Microbial determined using amplicon sequencing V4 region bacterial 16S rRNA gene fungal ITS1 region, substantially changed throughout process. Likewise, total population densities generally increased maturation. PerMANOVA revealed significant differences composition across time points, but not different types. By contrast, found sampling points. Results also indicated outcome likely depends on initial properties. Specifically, results suggested bitterness may restrain thereby having an impact souring. While moderately-hopped shifted dominance lactic acid bacteria, high-bitterness remained fairly constant, low densities. Bacterial moderate-bitterness resembled those traditional sours lambic hosting typical brewing species Pediococcus damnosus, Lactobacillus brevis Acetobacter sp. Furthermore, level have affected extraction compounds. More specifically, concentration compounds cis-3-methyl-4-octanolide, trans-3-methyl-4-octanolide, eugenol polyphenols higher high content. Altogether, our provide insights into beer, pave generation beers.