Go Stone Tea

Goishi-cha, 'go stone tea,' is a double fermented tea produced in the mountains of Otoyo Japan. In mid-June the leaves are harvested by cutting the branches. Leaves and branches are steamed in a big barrel and sorted. The leaves are stacked twenty inches thick, and covered with a straw mat. After a week, the leaves are covered with yellow mold. At this stage there are about six types of bacteria on the tea. The leaves are put in barrels and covered with the water used to steam fresh leaves. The barrels are covered and weights are put on the lid so the leaves remain submerged and not in contact with oxygen, which is anaerobic fermentation.

At the end of this fermentation a single type of lactic acid bacteria of vegetal origin remains. The leaves, fermented and compressed in the barrels for several weeks, are removed in early August, cut into squares of an inch and a half and dried for several days in the sun. As they dry the squares look like go game pieces, hence the name.

Whew! That's a lot of work.

So what is it like? Puerh? Fu brick? 

It tastes like tangy plums, lemon and dates. If you love puerh , fu brick and hei cha, it's not a guarantee that you'll like goishicha. Personally I love it. You can coax different flavors depending on how you brew. Brewing in gungfu style will bring out the tart notes in the first few steeping. Boiling 2 grams in 500 ml - 1 liter for 10 minutes brings out more flavors and reduces the acidity. Drinking it cold also reduces the tartness.

This method of tea production almost died out before the local government helped keep it going. Fermented everything is in style so hopefully that will keep demand up.

It's expensive and weird. But it's also fascinating and delicious. If you are big into tea Go Stone Tea is a path worth exploring.