When does lactic acid fermentation typically begin in lambic beers?

Lactic acid fermentation in lambic beers typically begins after the primary alcohol fermentation. This process is an essential part of traditional lambic brewing, where spontaneous fermentation occurs. Initially, wild yeast such as Saccharomyces takes over during primary fermentation, converting sugars into alcohol.

Once the primary fermentation is complete, the conditions become favorable for lactic acid bacteria, especially Lactobacillus and Pediococcus, to thrive. This transition is crucial because these bacteria metabolize residual sugars and produce lactic acid, which contributes to the distinctive sourness and complexity of lambic beers.

The timing of lactic acid fermentation is significant as it allows for the development of character and depth in the beer. The correct response reflects the understanding of this sequential fermentation process, where primary alcohol fermentation lays the groundwork for subsequent lactic acid fermentation to enhance the overall flavor profile.

If a response suggested lactic acid fermentation starts during or before primary alcohol fermentation, it would misunderstand the complementary roles each fermentation plays in the development of lambic beer. Each stage builds upon the previous one, with primary fermentation setting the stage for the desired sourness achieved through lactic acid fermentation.