Description
Doujiang is a traditional Chinese fermented soy milk produced by inoculating fresh soy milk with lactic acid bacteria and yeast, allowing the mixture to ferment at 20–30 °C for 12–24 hours.
Technical
During fermentation, lactic acid bacteria metabolize lactose to lactic acid, lowering the pH to 4.5–5.0 and inducing protein coagulation. Proteolytic enzymes from the microbes generate bioactive peptides, while volatile compounds such as diacetyl and acetaldehyde develop the characteristic tangy aroma. The resulting beverage is protein‑rich, more digestible, and has a creamy, slightly sour profile.
Science
Primary Reaction
lactose → lactic acid
Sensory Profile
Aroma ()
tangymilkyyogurt-likenuttyslightly sourearthyfermented
Origin & History
Civilization