The bioavailability of minerals, such as zinc and magnesium, has a significant impact on the fermentation process. These metal ions are known to influence the growth and metabolic activity of yeast, but there are few reports on their effects on lactic acid bacteria (LAB) metabolism during sour brewing. This study aimed to evaluate the influence of magnesium and zinc ions on the metabolism of Lactobacillus brevis WLP672 during the fermentation of brewers’ wort. We carried out lactic acid fermentations using wort with different mineral compositions: without supplementation; supplemented with magnesium at 60 mg/L and 120 mg/L; and supplemented with zinc at 0.4 mg/L and 2 mg/L. The concentration of organic acids, pH of the wort and carbohydrate use was determined during fermentation, while aroma compounds, real extract and ethanol were measured after the mixed fermentation. The addition of magnesium ions resulted in the pH of the fermenting wort decreasing more quickly, an increase in the level of L-lactic acid (after 48 h of fermentation) and increased concentrations of some volatile compounds. While zinc supplementation had a negative impact on the L. brevis strain, resulting in a decrease in the L-lactic acid content and a higher pH in the beer. We conclude that zinc supplementation is not recommended in sour beer production using L. brevis WLP672.

Lentils represent a promising alternative for beer production, potentially offering unique benefits and challenges. This study investigates the physicochemical properties of brewer’s wort derived from both barley and lentil grains. Specifically, it compares worts produced from raw and malted lentils, with and without the addition of amylase and protease enzymes. Key parameters such as filtration and saccharification times, pH, extract content, color, turbidity, polyphenol content, free amino nitrogen (FAN), nitrogen content, and metal ion and sugar composition were meticulously measured. Results indicate that both raw and malted lentils can be utilized to produce brewer’s wort, with the malting process enhancing extract levels. Notably, the addition of amylolytic enzymes resulted in the highest extract levels for both lentil types. Lentil-based worts exhibited significantly higher FAN levels and lower turbidity compared to barley malt worts. Despite barley malt’s established advantages in saccharification efficiency, filtration, and extract yield, lentils offer distinct benefits such as elevated FAN levels and unique color profiles. Enzyme treatments play a crucial role in optimizing lentil-based wort production, highlighting the potential for lentils in brewing applications.