Goishicha or ‘Go Stone Tea’ is a fermented tea made in central area of Japan’s Kochi prefecture near the town of Ōtoyo.

This is a tea style that very nearly escaped extinction. The knowledge of how to produce it was kept alive by 1 family at the turn of the millennium. The Ogasawara family managed to resurrect interest in this tea with the help of a cooperative they’ve built called “Otoyo Town Goishicha Producer’s Association”. What almost happened to Goishicha is not new, it’s a systemic problem that still threatens tea today. Many people don’t want to live in the countryside if a better, more exciting life in a big city is available. When Japan was going through its economic boom in the Showa era, the countrysides went through a mass exodus, as there was so much more opportunity to earn a living in the cities. My father in law’s life story follows this plot line. As he left his ancestral home in Kirishima, Kagoshima to live and work in Hiroshima, and eventually Osaka. I digress.

Awa Bancha and Goishicha have a lot in common, but a key difference is that Goishicha goes through two different types of fermentation’s, one aerobic, one anaerobic; while awa bancha is anaerobic only.

Goishicha is made from mature leaves picked in the summer months. Rather than picking specific leaves from the tea bush, traditional Goishicha production harvests entire branches that are flushed with leaves. These branches are steamed whole until everything is nice and soft. At this point the leaves are separated from the branches and left to wither in the sun, losing some of their moisture content.  These semi-dried leaves, covered in natural yeasts, molds, and bacteria are then brought into a shaded building and left to aerobically ferment for a little over a week, loosely sandwiched between straw mats.

After the aerobic fermentation, the leaves are loosely layered into a cedar barrel and flattened using a lid stacked with heavy rocks. The idea here is to press out the air between the leaves, creating conditions for anaerobic fermentation that will last for 2 to 3 weeks. This second phase is how goishicha develops its funky, distinctive flavors and health benefits.

Once the fermentation is complete, the layered mats of tea are removed from the barrel, cut to size, and dried in the sun.

This completes the production, and is now ready for sale.

It tastes very interesting. There is a distinctive fruitiness to it. I’ve heard many of my Chinese customers compare the aroma to Haw Flakes (Hawthorn Berries). After experiencing Haw Flakes myself, I agree with them, it is incredibly similar, though if I was using my own words I might say there is a fruit leather aspect to it, especially if it was heavy in strawberry. There is a spicy, raw ginger note. It seems medicinal — comparable to something in the lexicon of chinese herbal medicine. It really smells fermented, like, a bottle depot. A place where beer, wine, orange juice, etc have, over the course of years, seeped into the wooden sorting tables and manifested an aroma unique to this environment. Pretty neat.

The name ‘go ishi cha’ refers to the game of Go, the oldest board game that has been continuously played in the world. Go is played with black and white stones on a board with a grid. It is said that the cut pieces of tea resemble an active Go board as they sit outside on a mat drying in the sun.

https://www.goishicha.jp is the website of the Otoyo Town Goishicha Producer’s Association. Although it’s in Japanese, perhaps you can browse it with google lens if you find any interest!