There are several types of tea that are fermented or oxidized. In particular, “fermented tea” is less-known. This article guides you through “fermented tea,” which is a little strange.

What is fermented tea?

One of the well-known fermented teas is Pu’ er tea. Fermented tea is the only tea that has been fermented by microbes such as lactic acid bacteria not by the leaf enzymes. While fermented tea is rather rare by global standards, Japan is producing 4 types of fermented tea: “Goishicha,” “Awabancha,” “Batabatacha,” and “Ishizuchikurocha.”

Features of fermented tea’s flavor, aroma, color

Fermented tea has a sour flavor, which is unusual for tea. Of course, its taste, aroma, and color vary by tea. For example, Pu’ er tea’s flavor is similar to oolong tea’s flavor but more aromatic, and its color is brown. Goishicha has sourness and bitterness. Awabancha’s sourness gently spreads, and its color is yellow.

Features of fermented tea process

Broadly speaking, fermented tea has three manufacturing methods: “fermentation only by mold,” “fermentation only by lactic acid bacteria,” and “fermentation by mold and lactic acid bacteria.” Furthermore, the manufacturing process gradually varies by tea type. Here, let us see the manufacturing process of Pu’ er tea as an example, since it is the most common fermented tea. At first, the plucked leaves are heated to block oxidization. The leaves are kneaded, loosened, and dried. Then, the leaves are steamed and dried, followed by microbial fermentation. The leaves are dried again to conclude the process. Fermented tea is featured by its multiple tasks.

Types of fermented tea

Let us see famous fermented teas and domestic fermented teas.

Pu’ er tea

Pu’ er tea is a tea produced with kōji-mold and originated in Yunnan province, China. The history of Pu’ er tea is long and dates back to more than 2,000 years ago. It is said to be first documented in a history book in the Tang Dynasty. The color of Pu’ er tea is close to oolong tea. Its gentle earthy aroma and bitterness, which are unpalatable to some people, typically makes most of you addicted once you have tried it. It is supposed to be healthy and often served at esthetic salons and hot stone spas.


Miang is a traditional tea from northern Thailand. It is fermented by lactic acid bacteria. It is called “eating tea.” As its name suggests, it is to eat not to drink. Tea leaves plucked from Miang trees are heated and then fermented in a pot during a long period; for three months or even for one year. It has strong sour and bitter flavors. You can enjoy chewing the fermented leaves alone, but you can also eat them with spices such as ginger. A decreasing number of city people eat miang nowadays even in the north area. Many of them even do not know what miang is.


Goishicha is a tea produced in Ōtoyo-chō, Kōchi Prefecture. It has over 400 years of history. It used to be produced as a local specialty. The luxury product was bartered for salt, which was precious at that time. Goishicha is a tea whose plucked tea leaves have undergone deactivation of enzymes and fermentation by mold, followed by further fermentation by lactic acid bacteria. It contains a lot of lactic acid bacteria and is expected to eliminate constipation. It is especially attracting health-oriented people. It has less acid than other fermented teas and a similar flavor to wine.


Naka-gun and Katsuura-gun in Tokushima Prefecture are producing Awabancha. The history of Awabancha is long. It started when Kūkai, a Japanese Buddhist monk who studied in China , brought back and introduced tea culture to Japan. Ichibancha (first picked tea) is not plucked to let the leaves grow until summer, since soft tea leaves can melt in the manufacturing process. Deliberately hardened leaves characterize Awabancha. While fermentation by lactic acid bacteria provides sourness, the tea has no bitterness due to less catechin and caffeine and gives a refreshing flavor.


Batabatacha is a tea that has undergone fermentation by mold and is produced exclusively in Asahi-machi, Shimoniikawa-gun, Toyama Prefecture. Its feature is to drink brewed tea after foaming it. The Japanese onomatopoeia “batabata” is said to represent the stirring manner of constantly banging a tea whisk to foam the tea. It has a distinctive flavor similar to Dokudamicha (houttuynia cordata tea), but foaming makes a milder flavor. They say drinking with little salt is the real gourmet way.


Shizuchikurocha is a tea that has undergone fermentation by mold and fermentation by lactic acid bacteria and is produced in Saijo City, Ehime Prefecture. Once the number of manufactures sank to one and the technique was almost dying without inheritance. It came back from there and even became one of the nation’s intangible folklore cultural assets. Now Ishizukikurocha is called “illusory tea” or “tea of miracle.” It is slightly sour but not so strange. It is easy to drink with a fresh aroma. Ishizuchikurocha contains rich nutritive ingredients. It is becoming a popular healthy food.

January 08, 2023