Post-fermented tea
Encyclopedia
Post-fermented teas are a class of tea
s that have undergone a period of "aging" in open air, from several months to many years. The exposure of the tea to microflora, humidity and oxygen in the air causes it to undergo further oxidation through auto-oxidation, fermentation
, and possibly some reactivated oxidative enzymes in the tea. This alters the smell
of the tea, and typically mellows its taste, turning previously astringent or bitter teas into products that are thick and unctuous, with pleasant mouthfeels and aftertastes. In Chinese and Chinese-influenced East Asia
n cultures, post-fermented teas are collectively referred to as "dark tea" or "black tea" (黑茶, hēi chá) due to the dark brown infused liquors from this class of teas. This should not be confused with the black tea
commonly referred in Western culture
, which in East Asian cultures is called "red tea."
s or partially-oxidized oolong
-like teas, which are then allowed to slowly oxidize and undergo microbial fermentation over many years, thus turning into post-fermented tea. Alternatively, post-fermented teas can be created quickly through a ripening process spanning several months, as seen in ripened pu-erh. This ripening is done through a controlled process similar to composting, where both the moisture and temperature of the tea are carefully monitored. The resulting product from this fermentation is "finished" post-fermented tea.
Teas destined to be consumed as post-fermented teas are commonly sold as compressed tea of various shapes, including bricks, discs, bowls, or mushrooms. Ripened pu-erh teas are ripened in loose form prior to compression. Post-fermented teas can be aged for many years to improve their flavor. In the case of raw pu-erh tea, it can be aged up to 30 to 50 years without diminishing in quality, and ripened pu-erh can be aged up to 10 to 15 years. However, experts and aficionados disagree about the optimal age to stop the aging process.
Many Tibet
ans and Central Asia
ns use pu-erh or other post-fermented teas as a caloric food, boiled with yak butter
, sugar and salt to make yak butter tea
.
Tea
Tea is an aromatic beverage prepared by adding cured leaves of the Camellia sinensis plant to hot water. The term also refers to the plant itself. After water, tea is the most widely consumed beverage in the world...
s that have undergone a period of "aging" in open air, from several months to many years. The exposure of the tea to microflora, humidity and oxygen in the air causes it to undergo further oxidation through auto-oxidation, fermentation
Fermentation (food)
Fermentation in food processing typically is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts, bacteria, or a combination thereof, under anaerobic conditions. Fermentation in simple terms is the chemical conversion of sugars into ethanol...
, and possibly some reactivated oxidative enzymes in the tea. This alters the smell
Odor
An odor or odour is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also commonly called scents, which can refer to both pleasant and unpleasant odors...
of the tea, and typically mellows its taste, turning previously astringent or bitter teas into products that are thick and unctuous, with pleasant mouthfeels and aftertastes. In Chinese and Chinese-influenced East Asia
East Asia
East Asia or Eastern Asia is a subregion of Asia that can be defined in either geographical or cultural terms...
n cultures, post-fermented teas are collectively referred to as "dark tea" or "black tea" (黑茶, hēi chá) due to the dark brown infused liquors from this class of teas. This should not be confused with the black tea
Black tea
Black tea is a variety of tea that is more oxidized than the oolong, green, and white varieties.All four varieties are made from leaves of the shrub Camellia sinensis. Black tea is generally stronger in flavor and contains more caffeine than the less oxidized teas. Two principal varieties of the...
commonly referred in Western culture
Western culture
Western culture, sometimes equated with Western civilization or European civilization, refers to cultures of European origin and is used very broadly to refer to a heritage of social norms, ethical values, traditional customs, religious beliefs, political systems, and specific artifacts and...
, which in East Asian cultures is called "red tea."
Types
The best known of the post-fermented tea class is pu-erh tea; however, there are several other types of teas that are also of this class, including:- Pu-erh teaPu-erh teaPu'er, Pu-erh, Puer, also Po Lei or Bolay is a variety of post-fermented tea produced in Yunnan province, China. Post-fermentation is a tea production style in which the tea leaves undergo a microbial fermentation process after they are dried and rolled. This is a Chinese specialty and is sometimes...
(雲南普洱茶, yúnnán pǔ'ěr chá) - Liu'an tea (安徽六安籃茶, ānhùi lìu'ān lán chá)
- Liubao tea (廣西六堡茶, guǎnxī lìubǎo chá)
- Hunan dark tea (湖南黑茶, húnán hēi chá)
- Laobian tea (湖北佬扁茶, húběi lǎobiǎn chá)
- Kangzhuan tea (四川康砖茶, sìchuān kangzhuan chá)
- Bian tea (四川邊茶, sìchuān biān chá)
- Pha tea (发茶, fā chá)
Production
Many post-fermented teas do not arrive on the market as "finished" products; instead, they often start as green teaGreen tea
Green tea is made solely from the leaves of Camellia sinensis that have undergone minimal oxidation during processing. Green tea originates from China and has become associated with many cultures throughout Asia. It has recently become more widespread in the West, where black tea is traditionally...
s or partially-oxidized oolong
Oolong
Oolong is a traditional Chinese tea produced through a unique process including withering under the strong sun and oxidation before curling and twisting. Most oolong teas, especially those of fine quality, involve unique tea plant cultivars that are exclusively used for particular varieties...
-like teas, which are then allowed to slowly oxidize and undergo microbial fermentation over many years, thus turning into post-fermented tea. Alternatively, post-fermented teas can be created quickly through a ripening process spanning several months, as seen in ripened pu-erh. This ripening is done through a controlled process similar to composting, where both the moisture and temperature of the tea are carefully monitored. The resulting product from this fermentation is "finished" post-fermented tea.
Teas destined to be consumed as post-fermented teas are commonly sold as compressed tea of various shapes, including bricks, discs, bowls, or mushrooms. Ripened pu-erh teas are ripened in loose form prior to compression. Post-fermented teas can be aged for many years to improve their flavor. In the case of raw pu-erh tea, it can be aged up to 30 to 50 years without diminishing in quality, and ripened pu-erh can be aged up to 10 to 15 years. However, experts and aficionados disagree about the optimal age to stop the aging process.
Many Tibet
Tibet
Tibet is a plateau region in Asia, north-east of the Himalayas. It is the traditional homeland of the Tibetan people as well as some other ethnic groups such as Monpas, Qiang, and Lhobas, and is now also inhabited by considerable numbers of Han and Hui people...
ans and Central Asia
Central Asia
Central Asia is a core region of the Asian continent from the Caspian Sea in the west, China in the east, Afghanistan in the south, and Russia in the north...
ns use pu-erh or other post-fermented teas as a caloric food, boiled with yak butter
Yak butter
Yak butter is butter made from the milk of the domesticated yak . It is a staple food item and trade item for herding communities in south Central Asia and the Tibetan Plateau...
, sugar and salt to make yak butter tea
Butter tea
Butter tea, also known as po cha , cha süma , Mandarin Chinese: sūyóu chá or goor goor in local Ladakhi terms, is a drink of the Tibetans and Chinese minorities in southwestern China. It is also consumed in Bhutan. It is made from tea leaves, yak butter, and salt.-Usage:Drinking butter tea is a...
.