Jump to content

Black tea

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by 103.51.139.93 (talk) at 10:42, 3 March 2016 (Blends). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Black tea.
Tea plantation in Java, Indonesia.

Black tea is a type of tea that is more oxidized than oolong, green and white teas. Black tea is generally stronger in flavor than the less oxidized teas. All four types are made from leaves of the shrub (or small tree) Camellia sinensis. Two principal varieties of the species are used – the small-leaved Chinese variety plant (C. sinensis subsp. sinensis), used for most other types of teas, and the large-leaved Assamese plant (C. sinensis subsp. assamica), which was traditionally mainly used for black tea, although in recent years some green and white have been produced.

In Chinese and the languages of neighboring countries, black tea is known as "red tea" (Chinese 紅茶 hóngcha; Japanese 紅茶 kōcha; Korean 홍차 hongcha, Bengali লাল চা Lal cha, Assamese ৰঙা চাহ Ronga chah), a description of the colour of the liquid; the Western term "black tea" refers to the colour of the oxidized leaves. In Chinese, "black tea" is a commonly used classification for post-fermented teas, such as Pu-erh tea; outside of China and its neighbouring countries, "red tea" more commonly refers to rooibos, a South African herbal tea.

While green tea usually loses its flavor within a year, black tea retains its flavour for several years. For this reason, it has long been an article of trade, and compressed bricks of black tea even served as a form of de facto currency in Mongolia, Tibet and Siberia into the 19th century.[1] Although green tea has recently seen a revival due to its purported health benefits, black tea still accounts for over ninety percent of all tea sold in the West.[2]

Varieties

Generally, unblended black teas are named after the region in which they are produced.[3] Often, different regions are known for producing teas with characteristic flavors.

Tea Hanzi English Origin Source city Source region Source country Description
Tanyang Gongfu Tanyang Fujian Province China The king of the Fujian Artisan Red Teas. One of the three Famous Fujian Reds.
Zhenghe Gongfu Zhenghe Fujian Province One of the three Famous Fujian Reds, with a slight honey flavor.
Bailin Gongfu (白琳功夫) Bailin Fujian Province One of the three Famous Fujian Reds.
Zhengshan xiaozhong (Lapsang souchong) Mount Wuyi Fujian Province Dried over burning pine, thereby developing a strong smoky flavour.
Yin Junmei Silver Steed Eyebrow Mount Wuyi Fujian Province A higher grade version of Zhengshan xiaozhong (aka. Lapsang Souchong)
Jin Junmei Golden Steed Eyebrow Mount Wuyi Fujian Province One of the highest grade red teas in mainland China.
Keemun Qimen Anhui Province One of China's Famous Teas. The aroma of tea is fruity, with hints of pine, dried plum and floweriness.
Dian Hong Yunnan Province Well known for dark malty teas and golden bud teas.
Ying De Hong Guangdong Province The tea has a cocoa-like aroma and a sweet aftertaste, one can find a peppery note.
Jiu Qu Hong Mei "Nine Winding Red Plum" Hu Fou district Hangzhou Zhejiang Province This tea is characterised by tight fishhook-like leaves with a lustrous black color. The infusion is brightly reddish and has a long smooth aftertaste.
Tibeti Ya'an Sichuan Province A unique tea that can also be called brick tea; it has been known as "Tibetan tea" for centuries.
Sun Moon Lake Sun Moon Lake Nantou County Taiwan Honey rich tones, sweet osmanthus, cinnamon and peppermint.
Assam Assam India Full bodied, strong and distinctively malty tea from the lowlands of Assam. It is the highest produced tea in the world.[citation needed]
Darjeeling West Bengal Thin bodied, floral and fruity tea from Darjeeling with defining muscatel tones. Today often processed as a mixture of black, green and oolong elements, though still classed as black.
Munnar Kerala
Kangra Himachal Pradesh
Nilgiri Tamil Nadu Intensely aromatic, strong, and fragrant tea from the Nilgiri Hills of Karnataka, Kerala and Tamil Nadu.
Ceylon Sri Lanka It is grown on numerous estates which vary in altitude and taste. High-grown tea is honey golden liquor and light and is considered to be among the best teas in terms of its distinct flavor, aroma, and strength. Low-grown teas are a burgundy brown liquor and stronger. Mid-grown teas are strong, rich and full-bodied.
Nepali tea Nepal Similar to Darjeeling tea in its appearance, aroma and fruity taste, with subtle variation.

Blends

Black tea is often blended and mixed with various other plants in order to obtain a beverage.

Blend Description
Earl Grey tea Black tea with bergamot oil.[4]
English Breakfast tea Full-bodied, robust, and/or rich, and blended to go well with milk and sugar.
English afternoon tea Medium bodied, bright and refreshing. Strong Assam and Kenyan teas are blended with Ceylon which adds a light, brisk quality to the blend.
Irish breakfast tea Blend of several black teas: most often Assam teas and, less often, other types of black tea.
Masala chai Combines black tea, spices, milk, and a sweetener such as sugar or honey; a beverage from India (introduced by the British East India company to encourage tea consumption among Indians and to compete with Chinese tea plantations. Masala chai has been adapted in the West with changes to the method of preparation.[5]

Manufacture

  1. After the harvest, the leaves are first withered by blowing air on them.
  2. Then black teas are processed in either of two ways, CTC (Crush, Tear, Curl) or orthodox. The CTC method produces leaves of fannings or dust grades that are commonly used in tea bags but also produces higher (broken leaf) grades such as BOP CTC and GFBOP CTC (see gradings below for more details). This method is efficient and effective for producing a better quality product from medium and lower quality leaves of consistently dark color. Orthodox processing is done either by machines or by hand. Hand processing is used for high quality teas. While the methods employed in orthodox processing differ by tea type, this style of processing results in the high quality loose tea sought by many connoisseurs. The tea leaves are allowed to completely oxidize.[6]
    • Orthodox: The withered tea leaves are heavily rolled either by hand or mechanically through the use of a cylindrical rolling table or a rotovane. The rolling table consists of a ridged table-top moving in an eccentric manner to a large hopper of tea leaves, of which the leaves are pressed down onto the table-top. The process produces a mixture of whole and broken leaves, and particles which are then sorted, oxidized, and dried. The rotorvane (rotovane), created by Ian McTear in 1957 can be used to replicate the orthodox process.[6] The rotovane consisted on an auger pushing withered tea leaves through a vane cylinder which crushes and evenly cuts the leaves, however the process is more recently superseded by the boruah continuous roller, which consists of an oscillating conical roller around the inside a ridged cylinder.[6] The rotorvane can consistently duplicate broken orthodox processed black tea of even sized broken leaves, however it cannot produce whole leaf black tea.[7] The broken leaves and particles from the orthodox method can feed into the CTC method for further processing into fanning or dust grade teas.
    • CTC: "Cut, tear, curl" or "Crush, tear, curl" black teas is a production method developed by William McKercher in 1930. It is considered by some as a significantly improved method of producing black tea to the orthodox through the mincing of wither tea leaves.[8] The use of a rotovane to precut the withered tea is a common preprocessing method prior to feeding into the CTC [6] CTC machines then further shred the leaves from the rotavane by processing them through several series of contra-rotation rotors with surfaces patterning that cut and tear the leaves to very fine particles.[6]
  3. Next, the leaves are oxidized under controlled temperature and humidity. (This process is also called "fermentation", which is a misnomer since no actual fermentation takes place. Polyphenol oxidase is the enzyme active in the process) The level of oxidation determines the type (or "colour") of the tea; with fully oxidised becoming black tea, low oxidised becoming green tea, and partially oxidised making up the various levels of oolong tea.[9] This can be done on the floor in batches or on a conveyor bed with air flow for proper oxidation and temperature control. Since oxidation begins at the rolling stage itself, the time between these stages is also a crucial factor in the quality of the tea; however, fast processing of the tea leaves through continuous methods can effectively make this a separate step. The oxidisation has an important effect on the taste of the end product,[9] but the amount of oxidisation is not an indication of quality. Tea producers match oxidisation levels to the teas they produce to give the desired end characteristics.
  4. Then the leaves are dried to arrest the oxidation process.
  5. Finally, the leaves are sorted into grades according to their sizes (whole leaf, brokens, fannings and dust), usually with the use of sieves. The tea could be further sub-graded according to other criteria.

The tea is then ready for packaging.

Tea grading

Black tea grading
Fresh tea leaves of different sizes

Black tea is usually graded on one of four scales of quality. Whole leaf teas are the highest quality, with the best whole leaf teas graded as "orange pekoe". After the whole leaf teas, the scale degrades to broken leaves, fannings, then dusts. Whole leaf teas are produced with little or no alteration to the tea leaf. This results in a finished product with a coarser texture than that of bagged teas. Whole leaf teas are widely considered the most valuable, especially if they contain leaf tips. Broken leaves are commonly sold as medium grade loose teas. Smaller broken varieties may be included in tea bags. Fannings are usually small particles of tea left over from the production of larger tea varieties, but are occasionally manufactured specifically for use in bagged teas. Dusts are the finest particles of tea left over from production of the above varieties, and are often used for tea bags with very fast, very harsh brews. Fannings and dust are useful in bagged teas because the greater surface area of the many particles allows for a fast, complete diffusion of the tea into the water. Fannings and dusts usually have a darker colour, lack of sweetness, and stronger flavor when brewed.

Brewing

Generally, 2.25 grams of tea per 180 ml of water, or about a teaspoon of black tea per 6 oz. cup, should be used.[citation needed] Unlike green teas, which turn bitter when brewed at higher temperatures, black tea should be steeped in freshly boiled water. The more delicate black teas, such as Darjeeling, should be steeped for 3 to 4 minutes. The same holds for broken leaf teas, which have more surface area and need less brewing time than whole leaves. Whole leaf black teas, and black teas that will be served with milk or lemon, should be steeped 4 to 5 minutes.[10] Longer steeping times make the tea bitter (at this point, in the UK it is referred to as being "stewed"). When the tea has brewed long enough to suit the tastes of the drinker, it should be strained before serving.

The ISO Standard 3103 defines how to brew tea for tasting.[11]

Major producers

The biggest producers of black tea in the world are:[12]

Company Brand Share
Unilever Lipton 17.6%
PG Tips
Associated British Foods Twinings 4.4%
Tata Global Beverages Tetley 4.0%

Research

Plain black tea without sweeteners or additives contains caffeine but negligible quantities of calories or nutrients.[13] Some flavored tea with different herbs added may have less than 1 gram of carbohydrates. Black teas from the Camellia sinensis tea plant contain polyphenols known as thearubigins and theaflavins.[14]

Meta-analyses of observational studies have concluded that black tea consumption does not affect the development of oral cancers in Asian or Caucasian populations, esophageal cancer or prostate cancer in Asian populations, or lung cancer.[15][16][17][18][19]

Black tea consumption may be associated with a reduced risk of stroke.[20][21]

A 2013 Cochrane review of randomized controlled trials greater than 3 months duration concluded that long-term consumption of black tea only slightly lowers systolic and diastolic blood pressures (about 1-2 mmHg).[14][22]

A 2013 Cochrane review concluded that long-term black tea consumption lowers the blood concentration of LDL cholesterol by 0.43 mmol/L (or 7.74 mg/dL)[14] but overall this research remains inconclusive.[13]

See also

References

  1. ^ Bressett, Ken. "Tea Money of China". International Primitive Money Society Newsletter (44, August 2001).
  2. ^ "Tea's Wonderful History". chcp.org. Retrieved 9 July 2012.
  3. ^ Growing Black Tea plants, TeasyTeas, 2014, retrieved February 17, 2014
  4. ^ Richardson, Ben (6 April 2006). "Bergamot growers get whiff of success". BBC News.
  5. ^ http://coffeetea.about.com/od/historyculture/a/MasalaChaiHistory.htm
  6. ^ a b c d e Varnam, Alan H.; Sutherland, J. M. (1994), Beverages:Technology, Chemistry and Microbiology, Springer
  7. ^ Heiss, Mary Lou; Heiss, Robert J. (2007), The story of tea: a cultural history and drinking guide, Random House
  8. ^ Harbowy, Matthew E.; Balentine, Douglas A.; Davies, Alan P.; Cai, Ya (1997), "Tea Chemistry", Critical Reviews in Plant Sciences, 16 (5): 415–480
  9. ^ a b http://ratetea.com/topic/oxidation-of-tea/57/
  10. ^ Upton Tea Imports, "A Brief Guide to Tea" (PDF).
  11. ^ ISO3103, "ISO 3103".
  12. ^ Current Status and Future Development of Global Tea Production and Tea Products, Alastair Hicks (PDF), April 2009
  13. ^ a b "Black tea". Medline Plus, US National Library of Medicine. 2015. Retrieved 15 March 2015.
  14. ^ a b c Hartley L, Flowers N, Holmes J, Clarke A, Stranges S, Hooper L, Rees K (June 2013). "Green and black tea for the primary prevention of cardiovascular disease" (PDF). Cochrane Database Syst Rev (Systematic Review and Meta-Analysis). 6: CD009934. doi:10.1002/14651858.CD009934.pub2. PMID 23780706.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  15. ^ Wang W, Yang Y, Zhang W, Wu W (April 2014). "Association of tea consumption and the risk of oral cancer: a meta-analysis". Oral Oncol (Meta-Analysis). 50 (4): 276–81. doi:10.1016/j.oraloncology.2013.12.014. PMID 24389399.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  16. ^ Wang Y, Yu X, Wu Y, Zhang D (November 2012). "Coffee and tea consumption and risk of lung cancer: a dose-response analysis of observational studies". Lung Cancer (Meta-Analysis). 78 (2): 169–70. doi:10.1016/j.lungcan.2012.08.009. PMID 22964413.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  17. ^ Zheng J, Yang B, Huang T, Yu Y, Yang J, Li D (June 2011). "Green tea and black tea consumption and prostate cancer risk: an exploratory meta-analysis of observational studies". Nutr Cancer (Meta-Analysis). 63 (5): 663–72. doi:10.1080/01635581.2011.570895. PMID 21667398.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  18. ^ Lin YW, Hu ZH, Wang X, Mao QQ, Qin J, Zheng XY, Xie LP (February 2014). "Tea consumption and prostate cancer: an updated meta-analysis". World J Surg Oncol (Meta-Analysis). 12: 38. doi:10.1186/1477-7819-12-38. PMC 3925323. PMID 24528523.{{cite journal}}: CS1 maint: multiple names: authors list (link) CS1 maint: unflagged free DOI (link)
  19. ^ Zheng JS, Yang J, Fu YQ, Huang T, Huang YJ, Li D (January 2013). "Effects of green tea, black tea, and coffee consumption on the risk of esophageal cancer: a systematic review and meta-analysis of observational studies". Nutr Cancer (Systematic Review and Meta-Analysis). 65 (1): 1–16. doi:10.1080/01635581.2013.741762. PMID 23368908.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  20. ^ Shen L, Song LG, Ma H, Jin CN, Wang JA, Xiang MX (August 2012). "Tea consumption and risk of stroke: a dose-response meta-analysis of prospective studies". J Zhejiang Univ Sci B (Review). 13 (8): 652–62. doi:10.1631/jzus.B1201001. PMC 3411099. PMID 22843186.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  21. ^ Larsson SC (January 2014). "Coffee, tea, and cocoa and risk of stroke". Stroke (Review). 45 (1): 309–14. doi:10.1161/STROKEAHA.113.003131. PMID 24326448.
  22. ^ Liu G, Mi XN, Zheng XX, Xu YL, Lu J, Huang XH (October 2014). "Effects of tea intake on blood pressure: a meta-analysis of randomised controlled trials". Br J Nutr (Meta-Analysis). 112 (7): 1043–54. doi:10.1017/S0007114514001731. PMID 25137341.{{cite journal}}: CS1 maint: multiple names: authors list (link)