Seleção e avaliação de microrganismos para elaboração de cerveja artesanal estilo Catharina Sour

Abstract

This study selected and evaluated starter cultures for the production of Catharina Sour beer with acerola in three stages: (1) selection of eleven Saccharomyces cerevisiae strains from the Agricultural Microbiology Culture Collection (CCMA), one commercial yeast (S-04) as control, and Lactiplantibacillus plantarum CCMA 0743; (2) microbiological, physicochemical, and chromatographic evaluation in 100- and 500-mL microfermentations; and (3) small-scale production with physicochemical, microbiological, chromatographic, and sensory analyses. Strains CCMA 0731, 0732, 1746, 0188, and 0543 were excluded due to fermentative and physiological limitations. CCMA 0200 and CCMA 0233 stood out for their adequate maltose assimilation, tolerance to 5.5% ethanol, 8 IBU of hops, and pH 3.1, in addition to medium/high flocculation. In 100-mL microfermentations, L. plantarum CCMA 0743 reduced wort pH to 3.3 and produced 9.5 g/L of lactic acid within 24 h. The selected yeasts decreased °Brix from 12 to ~5, producing 32.9–53.8 g/L of ethanol, confirming fermentative efficiency. S-04 exceeded the target alcohol content, whereas CCMA 0200 (4.2% v/v) and CCMA 0233 (4.9% v/v) remained within the recommended range. All strains maintained stable populations (~7.05–7.87 Log cells/mL). In 500-mL trials, CCMA 0233 reduced °Brix to 4.45, producing 39 g/L of ethanol, while CCMA 0200 yielded higher glycerol concentrations (3.7 g/L). The strains showed populations ranging from 7.6 to 7.85 Log cells/mL, and as in the 100- and 500-mL assays, cell counts remained stable (~6.77–7.85 Log cells/mL). S-04 resulted in higher ethanol content and lower glycerol production. Chromatographic analysis (GC–MS) indicated aromatic diversity for CCMA 0200 and CCMA 0233, including terpineol and 1-octanol. In small-scale fermentations, CCMA 0233 showed a balance between population, ethanol (4.9% v/v), and glycerol (3.2 g/L), conferring a fruity, floral, and acidic sensory profile that was well accepted by panelists. CCMA 0200 maintained good performance, with greater smoothness and moderate acidity, whereas S-04 exhibited strong alcoholic notes and reduced complexity, diminishing refreshment. Sensory tests confirmed the predominance of an acidic and fruity profile for CCMA 0233, smoothness for CCMA 0200, and alcoholic character for S-04. Acerola extract proved suitable as a brewing adjunct. CCMA 0200 and 0233 are suitable to produce Catharina Sour with acerola, with CCMA 0200 recommended as main option for microbreweries seeking innovation and valorization of Brazilian biodiversity.