What You Need to Know
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.
The Science
Primary Reaction
C2H5OH + O2 → CH3COOH + CO2