Fermented tea in the center of attention even in Japan – Goishi Cha

There are many varieties of tea in Japan, but there is a very unusual, fermented tea that is made in Kochi prefecture. Goishi Cha has been produced in this town in the mountains for more than 400 years. It has become popular recently as a health food due to its high acidophilus content.
“It’s said that Goishi Cha came from China more than 400 years ago. It’s known for the distinct flavor that results from the two-step fermentation. At its peak, we produced more than 100 tons, but by the end of the Showa era, only one producer was left, and we faced the tradition being lost. A cooperative was formed to preserve the tea, and we now have a cooperative of 4 growers and 1 company.” (Yuji Yoshimura from the Otoyo Goishi Cha Cooperative)

A distinct acidity spreads throughout your mouth when you take a sip of the Goishi Cha. It resembles the Chinese Pu’er Tea, which is also fermented, but it is more delicate and once you become used to the acidity, the distinct flavor becomes pleasant. The plant based acidophilus is said to be more than 23 times that of Pu’er Tea, and continues to thrive inside your body helping to maintain a healthy digestive system and fight against hay fever, influenza, hardening of the blood vessels, high blood pressure and hyperlipidemia. Research on its effects are being carried out.

While black teas are fermented through oxidation, Goishi Cha uses microorganisms. Tea leaves are placed into a large vat and steamed with the branches intact. Then just the leaves are spread out onto a strainer and air dried to allow mold to form, then placed in a wooden vat again for the second fermentation. The tea leaves are placed in layers, almost like Japanese style pickles. The tea leaves are finely cut then air dried to create Goishi Cha. Since micro organism are used for the fermentation, Goishi Cha can only be made by the mold that lives in the steam room and on the wooden vats.

“Goishi Cha is only made from June to August. We chose sunny days to air dry it, and the name derives from how the black color of the tea leaves look like Goishi pieces from afar.”

Using micro organism for fermentation is very unusual, and is a method used only in certain areas of China. Yet there are 4 locations in Japan with 3 in the Shikoku region.
Like other forms of agriculture and traditional culture, Goishi Cha production is facing the crisis of an aging community. But it is sure to gain popularity and attention once people recognize the taste and health benefits. It is delicious and healthy. We truly hope that many more people recognize that such as tea exists right here in Japan.