Low Lactic Acid-Producing Strain of Lachancea thermotolerans as a New Starter for Beer Production

Growing consumer interest in new beer flavors is contributing to the application of innovative materials and non-Saccharomyces yeast in brewing. The goal of this study was to test the impact of the low lactic acid-producing Lachancea thermotolerans MN477031 strain on the process of fermenting beer wort, with two different concentrations of bitter compounds, and on the quality of the beer produced. Qualify factors were broadly analyzed, including ethanol content, apparent degree of fermentation, sugars, organic acids, free amino nitrogen, glycerol, volatile compounds, ions and so on. It was proven that the L. thermotolerans MN477031 strain demonstrated a high capacity for rapid initiation of wort fermentation, and a tolerance to hop-derived compounds. As a result, the alcohol content in beer from this method of production was approximately 20% lower, while the content of the real extract was significantly higher in comparison to commercial Safbrew T-58. This strain stands out from many strains of L. thermotolerans due to the low lactic acid production and only marginal influence on pH decrease compared to Saccharomyces cerevisiae. Therefore, the potential of MN477031 in the production of different types of beer (not only sour) is very high. The composition of volatile compounds in L. thermotolerans beer differs—not only in terms of the use of the strain, but also in hop variety.