Goishicha is one of four post-fermented teas in Japan. 2 stage fermentation develops lactic acids that give you natural sour tastes.
The name of goishicha comes from the fact that the scene of drying leaves after the 2nd fermentation is looked like Go stones. The amount of lactic acid bacteria in Goishicha has more than that of Pu-erh tea.
Goishicha is a registered trademark of Otoyo-cho Goishicha Cooperative.