Description
Ancient Chinese su is produced by fermenting polished rice into alcohol, then oxidizing the ethanol to acetic acid with Acetobacter, followed by aging in copper or clay vessels.
Technical
The process begins with koji mold (Aspergillus oryzae) converting starches to sugars, which Saccharomyces cerevisiae ferments into ethanol. Acetobacter species then aerobically oxidize the ethanol to acetic acid, lowering the pH to 2.5–3.0. The vinegar is aged for months to mellow flavors and reduce volatile sulfur compounds.
Science
Primary Reaction
C2H5OH + O2 → CH3COOH + CO2
Sensory Profile
Aroma ()
fragrantmildsweetacidicearthynuttyfloralcaramelizedfruitywood-aged