1. The preparation and fermentation in the early stage are the same as those in the wine. Grapes are prepared in a container, mashed, fermented for two to three days, and pre-fermented at 25-28 degrees.

2. After filtering once, carry out post-fermentation at 30-35 degrees. Mix a portion of wine with a portion of boiling water, cool, then add a proper amount of vinegar koji or 5% rice vinegar as the base material according to the instructions, put it in a jar, open the lid and ferment, and cover it with a layer of gauze to prevent insects. Ferment until a complete layer of acetic acid bacteria white film is produced on the surface, and ferment for 3-4 days.

3. Finally, filter out the clarified vinegar, put it into the pot, cook until the pot is thin and bubbly, turn off the fire, and bottle and seal it while it is hot.