Fermented tea

"Dark tea" redirects here. For the Brooklyn-based music project, see Dark Tea (musical group).
Not to be confused with Black tea.

Fermented tea
Golden melon pu'er tea
Chinese黑茶
Literal meaningBlack/dark tea
Hanyu Pinyinhēichá
Hokkien POJhek-tê
Alternative Chinese name
Traditional Chinese後發酵茶
Simplified Chinese后发酵茶
Literal meaningpost-fermented tea
Hanyu Pinyinhòu fājiào chá

Fermented tea (also known as post-fermented tea or dark tea) is a class of tea that has undergone microbial fermentation, from several months to many years. The exposure of the tea leaves to humidity and oxygen during the process also causes endo-oxidation (derived from the tea-leaf enzymes themselves) and exo-oxidation (which is microbially catalysed). The tea leaves and the liquor made from them become darker with oxidation. Thus, the various kinds of fermented teas produced across China are also referred to as dark tea, not be confused with black tea, which is actually referred to as "red tea" (hong cha, 红茶) in Chinese. The most famous fermented tea is pu'er produced in Yunnan province.[1][2]

The fermentation of tea leaves alters their chemistry, affecting the organoleptic qualities of the tea made from them. Fermentation affects the smell of the tea and typically mellows its taste, reducing astringency and bitterness while improving mouthfeel and aftertaste. The microbes may also produce metabolites with health benefits.[1][3] Additionally, substances like ethyl carbamate (urethane) may be produced.[4]

The fermentation is carried out primarily by molds. Aspergillus niger was implicated as the main microbial organism in the pu'er process,[1][5][6] but that species identification has been challenged by comprehensive PCR-DGGE analysis, which points to Aspergillus luchuensis as the primary agent of fermentation.[7][8][9][10]

Most varieties of fermented teas are produced in China, its country of origin, with several varieties also produced in Korea[11] and Japan.[12] In Myanmar, lahpet is a form of fermented tea that is eaten as a vegetable, and similar pickled teas are also eaten or chewed in northern Thailand and southern Yunnan.[13]

  1. ^ a b c Mo, Haizhen; Zhu, Yang; Chen, Zongmao (2008). "Microbial fermented tea–a potential source of natural food preservatives". Trends in Food Science & Technology. 19 (3): 124–130. doi:10.1016/j.tifs.2007.10.001.
  2. ^ Lv, Hai-peng; Zhang, Ying-jun; Lin, Zhi; Liang, Yue-rong (2013). "Processing and chemical constituents of Pu-erh tea: A review". Food Research International. 53 (2): 608–618. doi:10.1016/j.foodres.2013.02.043.
  3. ^ Ling, Tie-Jun; Wan, Xiao-Chun; Ling, Wei-Wei; Zhang, Zheng-Zhu; Xia, Tao; Li, Da-Xiang; Hou, Ru-Yan (2010). "New Triterpenoids and Other Constituents from a Special Microbial-Fermented Tea—Fuzhuan Brick Tea". Journal of Agricultural and Food Chemistry. 58 (8): 4945–4950. doi:10.1021/jf9043524. ISSN 0021-8561. PMID 20307093.
  4. ^ Tang, A. S.; Chung, S. W.; Kwong, K.; Xiao, Y.; Chen, M. Y.; Ho, Y. Y.; Ma, S. W. (2011). "Ethyl carbamate in fermented foods and beverages: Dietary exposure of the Hong Kong population in 2007–2008". Food Additives & Contaminants. Part B, Surveillance. 4 (3): 195–204. doi:10.1080/19393210.2011.605524. PMID 24786007. S2CID 1852027.
  5. ^ Gong, Jia-shun; Zhou, H.J.; Zhang, X.F.; Song, Shan; An, W.J. (2005). "Changes of Chemical Components in Pu'er Tea Produced by Solid State Fermentation of Sundried Green Tea". Journal of Tea Science. 25 (3): 126–132.
  6. ^ Abe, M.; Takaoka, N.; Idemoto, Y.; Takagi, C.; Imai, T.; Nakasaki, K. (2008). "Characteristic fungi observed in the fermentation process for Puer tea". International Journal of Food Microbiology. 124 (2): 199–203. doi:10.1016/j.ijfoodmicro.2008.03.008. PMID 18455823.
  7. ^ Mogensen, J.M.; Varga, J.; Thrane, U.; Frisvad, J.C.; Imai, T; Nakasaki, K (2009). "Aspergillus acidus from Puerh tea and black tea does not produce ochratoxin A and fumonisin B2". International Journal of Food Microbiology. 132 (2–3): 141–144. doi:10.1016/j.ijfoodmicro.2009.04.011. PMID 19439385.
  8. ^ Varga, J.; Frisvad, J.C.; Kocsubé, S.; Brankovics, B.; Tóth, B.; Szigeti, G.; Samson, R.A. (2011). "New and revisited species in Aspergillus section Nigri". Studies in Mycology. 69 (1): 1–17. doi:10.3114/sim.2011.69.01. PMC 3161757. PMID 21892239.
  9. ^ Haas, Doris; Pfeifer, Bettina; Reiterich, Christoph; Partenheimer, Regina; Reck, Bernhard; Buzina, Walter; Samson, R.A. (2013). "Identification and quantification of fungi and mycotoxins from Pu-erh tea". International Journal of Food Microbiology. 166 (2): 316–322. doi:10.1016/j.ijfoodmicro.2013.07.024. PMC 3161757. PMID 21892239.
  10. ^ Hong, Seung-Beom; Lee, Mina; Kim, Dae-Ho; Varga, Janos; Frisvad, Jens C.; Perrone, Giancarlo; Gomi, Katsuya; Yamada, Osamu; Machida, Masayuki; Houbraken, Jos; Samson, Robert A. (2013). McCluskey, Kevin (ed.). "Aspergillus luchuensis, an industrially important black Aspergillus in East Asia". PLOS ONE. 8 (5): e63769. Bibcode:2013PLoSO...863769H. doi:10.1371/journal.pone.0063769. ISSN 1932-6203. PMC 3665839. PMID 23723998.
  11. ^ Moon, Doo-Gyung (2 April 2020). "The Characteristics of Korean Traditional Post-Fermented Tea (Chungtaejeon)". Bioactive Compounds in Nutraceutical and Functional Food for Good Human Health. doi:10.5772/intechopen.91855. ISBN 978-1-83880-887-7.[predatory publisher]
  12. ^ Hua-Fu Wang; Xiao-Qing You; Zong-Mao Chen (2002). Zhen, Yong-su (ed.). Tea: Bioactivity and Therapeutic Potential. Taylor & Francis. p. 104. ISBN 9780203301272. Retrieved 11 August 2014.
  13. ^ Cite error: The named reference Chemistry was invoked but never defined (see the help page).