Sours, in the context of fermentation, refer to a category of beverages or foods that have a tangy or acidic flavor profile. This sourness is primarily produced by the action of specific bacteria and yeasts during the fermentation process. Common examples include sour beers, such as those produced by the Brettanomyces yeast, and fermented foods like sauerkraut and kimchi. The fermentation process involves the conversion of sugars into acids, gases, or alcohol, resulting in the characteristic sour taste. Lactic acid bacteria, such as Lactobacillus, play a significant role in this process, especially in dairy products like yogurt. The balance of flavors and acidity can vary widely, depending on the ingredients and fermentation conditions used.