Sauerbiere

Sauerbiere is a German category of sour beers whose tartness is achieved by deliberate souring during brewing or through long aging. The term covers a variety of beer styles produced in Germany, especially in Bavaria and Franconia, from pale lagers to amber ales, and can include blends or mixed fermentations with wild yeasts or bacteria.

Historically, souring was common before modern sanitation and refrigeration, when beers aged in wooden casks could develop acidity through lactobacillus and other microflora. This sour character was sometimes used to extend shelf life and create a contrasting alternative to sweeter beers. Traditional Sauerbiere could be served in inns and taverns, offering a refreshing tartness in warmer seasons or during scarcity.

Today, Sauerbiere are part of the broader revival of sour beer in craft brewing. Modern producers employ controlled methods such as kettle souring with Lactobacillus, barrel aging with mixed cultures, or spontaneous fermentation, often with fruit additions. The resulting beers are typically light to medium-bodied with noticeable acidity, ranging from citrusy to wine-like, and color from pale to amber. While distinct styles like Berliner Weisse or Gose are considered separate, Sauerbiere share the underlying souring principle.