2.4. Alcoholic fermentation
H. erinaceus powders were added to water in different concentrations (1.25% w/v, 2.5% w/v, 5% w/v), and initial sugar concentration was adjusted to 25 °Brix. For sterilization, 200 ppm of potassium metabisulfite (K2S2O5) was added and placed for 2 h at room temperature. For alcohol fermentation, 1 g/L of dry yeast (S. cerevisiae) was added and the mixture was incubated at 27 °C for 6 days. When the alcoholic fermentation was completed, the intermixture was centrifuged (350× g, 10 min) and the supernatant was kept in a 70 °C water bath for 30 min. Each batch was stopped when the alcohol content reached 15% (w/v).