Goishicha

These peculiar squares might be one of Japan’s rarest creations in the world of tea. Goishicha is a twice-fermented tea from the small town of Otoyo in Kochi prefecture and its name stems from its striking shape: tea leaves are piled up, condensed into thin layers and cut into square pieces that resemble the stones used to play the game of Go.

During the production process, Goishicha undergoes two separate fermentation processes. The primary fermentation is aerobic and takes place over the course of 7 to 10 days, where the tea is spread out onto straw mats in 50 to 70 cm high piles. For the second fermentation, the tea leaves are soaked in a cedar vat along with the leaf juices that were collected during the steaming process that takes place prior to fermentation, which takes about 20 days. This lactic acid fermentation adds a sour note reminiscent of lemon that is typical for Goishicha. While the dry chunks smell slightly earthy with a mix of soy sauce and dried tobacco leaves, the taste is brightly acidic, combined with a strong savoury note that calls to mind various mushrooms and a fermentation funk one would expect from a strong red miso paste. In the mouth, it’s full, viscous, and smooth while still retaining a feeling of lightness thanks to its acidity.

We recommend using one 2 to 3 g chunk of tea with 500 to 1000 ml of boiling water and steeping for a few minutes. Using this guideline will yield two full-bodied steeps.

Written by Sigi

The origin of Goishicha

Goishicha's history traces back to the Bulang minority of China’s Yunnan province—they produced a sour tea by fermenting it in bamboo tubes that were buried underground. This fermentation process made its way over to Japan as part of the many cultural exchanges during the Tang dynasty and was passed down among farming households in Otoyo as they traded their fermented tea for salt with the islands of the Seto Inland Sea.

What Sets our Goishicha Apart

During fermentation, the leaves are periodically moistened with water. While most producers rely on local tap water, our Goishicha comes from the only farmer who uses deep-sea water, a practice rooted in the historic trading in the Seto Inland Sea.

With a hardness of 3000 TDS, this deep-sea water is exceptionally mineral-rich. Its unique composition helps stabilize the fermentation and promotes a clean, lactic development of flavor. The result is a Goishicha of remarkable minerality and natural umami, unlike any other.

Visiting the Goishicha producer at his factory in Kochi, Japan.