The major organic acid in this fermentation was acetic acid and its concentration increased from 11.70 to 21.56 mg/ml after 9 days of fermentation. The amount of acetic acid in H. erinaceus vinegar was lower than that of other vinegars, including white wine vinegar, red wine vinegar, alcohol vinegar, malt vinegar, and cider vinegar, which ranged from 48.63 to 62.31 mg/ml