What do you mean by one vinegar shower and two vinegar showers?

First vinegar, second vinegar. One vinegar shower is called the first vinegar, and the second vinegar shower refers to the vinegar brewed for the second time. The first acetic acid shower was violent and pungent, and the second acetic acid shower was long and far-reaching. Soaking vinegar is a process of naturally fermenting vinegar. The purpose is to extract vinegar from vinegar fermented grains, which can remove impurities, increase the brightness of vinegar, make the contents of vinegar leach evenly, and also play a role in filtering.