Lactic acid fermentation

Japanese: 乳酸発酵

Fermentation in which lactic acid bacteria break down sugar to produce lactic acid. Found in yogurt, pickles, and kimchi—the most familiar fermentation worldwide.

Lactic acid fermentation is the reaction in which lactic acid bacteria break down sugar to produce lactic acid. This lowers the environmental pH, suppressing spoilage bacteria—one reason fermented foods keep so well.

Yogurt, nukazuke, kimchi, sauerkraut—lactic acid fermentation is involved in fermented foods across the globe. Even during miso aging, lactic acid bacteria contribute acidity and complexity.

Lactic acid bacteria come in two types: homofermentative, producing only lactic acid, and heterofermentative, also generating CO₂ and alcohol. Which type is active dramatically changes the flavor profile.

Related words

Lactic acid bacteria (LAB)

A general term for bacteria that produce lactic acid from sugars. They contribute to a wide range of fermented foods including pickles, yogurt, and miso, creating acidic environments that improve preservation.

Yogurt

A semi-solid food made by fermenting milk with lactic acid bacteria. The bacteria convert lactose into lactic acid, coagulating proteins to create its characteristic texture.

Nukazuke (Rice Bran Pickles)

A uniquely Japanese pickle made by embedding vegetables in a fermented rice bran bed, where lactic acid bacteria and yeast create distinctive flavors.

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