Fermentation strategy and yeast selection as drivers of the target metabolomic profile and sensory acceptance of Catharina Sour beer enriched with Caatinga passion fruit

Catharina Sour, a widely appreciated craft beer, is a Brazilian beer style characterized by the addition of fruit and occurrence of lactic acid fermentation. This study aimed to investigate the impact of fermentation strategy on the targeted metabolite profile and consumer acceptance of Catharina Sour beer enriched with the Brazilian native fruit Passiflora cincinnata Mast. The conventional kettle sour process was compared with a single-step fermentation using Lachancea thermotolerans . In the conventional kettle sour method, lactic and alcoholic fermentations were achieved using Lactobacillus buchneri and Saccharomyces cerevisiae , respectively. Compared with the single-step fermentation, the traditional method yielded higher concentrations of ethanol (32.76 g/L), glycerol (4.31 g/L), lactic acid (4.71 g/L), and total phenolic compounds. The addition of Caatinga passion fruit enriched the Catharina Sour beer with phenolic compounds associated with biological activity, predominantly myricetin, gallic acid, (+)-catechin, and procyanidin A2. Although different fermentation strategies produced different metabolite profiles of the sour beer, they did not affect the acceptability of the product by consumers. Thus, this study highlighted the potential of L. thermotolerans yeast for producing sour beers using a simplified production process.