Ōtoyo
A town in the mountains of Kōchi on Shikoku, and the only place goishicha is still made. The process runs two fermentations rather than one: steamed leaf is heaped and left to grow a mould, then packed into a barrel under a stone for a second, lactic fermentation, then cut into small squares and dried on mats — the squares are what give the tea its name, after the black stones used in go. Two-stage fermentation of this kind is otherwise a mainland Asian practice, and it survives here in the hands of a very small number of households.
Elevation
Recorded at 200–700 metres.
How firm this is: Inferred from general knowledge of the district rather than measured or taken from a source that states it.
When it is picked
Summer again, and a two-stage fermentation. Goishicha is made from mature leaf steamed in mid-summer, first moulded under a fungal growth and then packed for a second, anaerobic lactic fermentation, before being cut into blocks and sun-dried. Like Awa bancha it needs old leaf and heat, so it is made when the shincha districts have long finished.
How firm this is: Inferred from general knowledge of the district rather than measured or taken from a source that states it.
How production is organised
A very few producers in mountain Kochi keeping a two-stage fermented tea alive, largely for a regional market and for the drink's role in a local rice-gruel preparation. The category's survival is a heritage matter rather than a commercial one.
How firm this is: Inferred from general knowledge of the district rather than measured or taken from a source that states it.
How the name is written
Also transliterated as otoyo, o toyo, goishicha. Romanisations of a district name vary by system and by vendor, and a packet spelling one way is not describing a different place.
Teas this region is known for
- Goishicha — Genuinely sour rather than earthy, which is what the lactic fermentation does and what separates it from Chinese dark tea entirely.
Other growing regions in Japan
The neighbouring districts are the useful comparison: they share a country, a grading convention and often a cultivar, so what differs between them is closer to terroir than anything a cross-border comparison can isolate.
Sources
- TeaHQ editorial synthesis — TeaHQ
This page is TeaHQ’s own synthesis throughout. No external document stands behind the elevation band, the climate note or the character described above, which is why each carries its confidence in the open.