What is kahm yeast?

Kahm yeast (Latin name: Brettanomyces anomalus) is a type of yeast that commonly forms as a white, creamy layer on the surface of fermenting foods, such as vegetables, fruits, and beverages. It is often seen in lacto-fermented foods like sauerkraut, kimchi, and pickles.

Kahm yeast is harmless and not toxic, but it can alter the flavor and texture of the fermented food it grows on. Some describe the taste of kahm yeast as bitter or sour, while others find it to be slightly alcoholic or off-flavored.

To prevent kahm yeast growth, it is recommended to use fresh ingredients, maintain proper fermentation conditions (such as temperature and salt concentration), and ensure the fermenting vessel is clean and sanitized.

If kahm yeast does develop on your ferment, you can simply scrape it off and discard it before enjoying your fermented food. It is important to note that kahm yeast should not be confused with harmful molds or pathogens, which can pose health risks.