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A cup of coffee

Workers sorting and pulping coffee beans in Guatemala

Mature coffee fruit still on the plant

Main article: Beverages (nonalcoholic)

This is a background article. See Psychological studies of coffee

Coffee is a widely consumed beverage prepared from the roasted seeds — commonly referred to as beans — of the coffee plant. It can be consumed cold or hot. A typical 200 ml (7 fluid ounces) cup of coffee contains 80–140 milligrams of caffeine, depending on the bean and method of roasting and preparation.[1] Some people drink coffee "black" (plain), while others sweeten their coffee or add milk, cream or non-dairy creamer. The majority of all caffeine consumed worldwide comes from coffee, as much as 85% in some countries.[2] Coffee, along with tea and water, is one of the most popular beverages world-wide, its volume amounting to about a third of that of tap water in North America and Europe.[3] In 2003, coffee was the world's sixth largest agricultural export in value, behind wheat, maize, soybeans, palm oil and sugar.[4]


The English word "coffee" is believed to be derived ultimately from the name of the place, 'kaffa' in southern Ethiopia, where coffee was cultivated. It is called būnn (ቡን) or būnnā (ቡና) in Ethiopia in Amharic and būnnī (ቡኒ) in Tigrinya, and other variations on the original būnn in other languages. Coffee's Arabic name, qahwa (قهوة), is a truncation of qahwat al-būnn, or wine of the bean.

The Arabic qahhwa was borrowed by Ottoman Turkish as kahve, which in turn was borrowed into Italian as caffè with French, Portuguese] and Spanish as café.[5] Early forms date back to the last decade of the 16th century, but the word "coffee" itself did not come into use until the early to mid 1600s[6]

Coffee seeds

Main article: Coffee varietals

Coffea arabicaBrazil

Freshly harvested berries of Coffea robusta

Dried berries of Coffea robusta

There are two main species of the coffee plant, the older one being Coffea arabica. Coffee is thought to be indigenous to south-western Ethiopia, specifically from Kaffa, from which it may have acquired its name.[7] While more susceptible to disease, it is considered by most to taste better than the second species, Coffea canephora (robusta). Robusta, which contains about 40–50% more caffeine, can be cultivated in environments where arabica will not thrive and probably originated in Uganda.[7] For this reason it is used as an inexpensive substitute for arabica in many commercial coffee blends. Compared to arabica, robusta tends to be bitter and has little flavor, with a telltale "burnt rubber" or "wet cardboard" aroma and flavor. Good quality robustas are used in some espresso blends to provide a better "crema" (foamy head), and to lower the ingredient cost. In Italy, many espresso blends are based on dark-roasted robusta. The large industrial roasters use a steam treatment process to remove undesirable flavors from robusta beans for use in mass-marketed coffee blends.[8] Other species include Coffea liberica and Coffea esliaca, believed to be indigenous to Liberia and southern Sudan respectively.[7]

Arabica coffees were traditionally named by the port from which they were exported, the two oldest being Mocha, from Yemen, and Java, from Indonesia. The modern coffee trade is much more specific about origin, labeling coffees by country, region, and sometimes even the producing estate. Varietal[9] is a botanical term denoting a taxonomic category ranking below species, a designation more specific than arabica or robusta and unrelated to the coffee's place of origin. Coffees consisting entirely of beans from a single varietal, bourbon, for example, are generally so referred to, with a reference to their place of origin (as in: Rwanda Blue Bourbon). Coffee aficionados may even distinguish auctioned coffees by lot number.[10]

Most arabica coffee beans originate from one of three growing regions; Latin America, East Africa/Arabia and Asia/Pacific. Beans from different countries or regions usually have distinctive characteristics such as flavour (flavour criteria include terms such as "citrus-like" or "earthy"), aroma (sometimes "berry-like" or "flowery"), body or mouthfeel, and acidity. Acidity refers to a tangy or clean-tasting quality, typically present in washed or wet processed coffees. It does not refer to a coffee's pH level. (Black coffee has a pH of around 5).[11] These distinguishing taste characteristics are dependent not only on the coffee's growing region, but also on its method of process and genetic subspecies or varietal.[12][13]

A peaberry, (also sometimes called a "Caracoli" bean[14]) is a coffee bean that develops singly inside the coffee cherry instead of the usual pair of beans. This situation occurs 5–10% of the time. Since flavour is concentrated when only a single bean is grown inside the cherry, these beans (especially Arabica) are highly prized.[15]



Roasted coffee beans

Main article: Coffee processing

Much processing and human labour is required before coffee berries and its seed can be processed into the roasted coffee with which most Western consumers are familiar. Coffee berries must be picked, defruited, dried, sorted, and, in some processes, aged.[16]

Coffee is usually sold in a roasted state, and the roasting process has a considerable degree of influence on the taste of the final product. All coffee is roasted before being consumed. When coffee beans are roasted, they turn much darker because their sucrose caramelizes. Coffee can be sold roasted by the supplier; alternatively it can be home roasted.[16]

Coffee roasting is a complicated chemical process that creates the distinctive flavor of coffee from a bland bean. Unroasted beans contain all of coffee’s acids, protein, and caffeine — but none of its taste. It takes heat to spark the chemical reactions that turn carbohydrates and fats into aromatic oils, burn off moisture and carbon dioxide, and alternately break down and build up acids, unlocking the characteristic coffee flavor.[16] One of these aromatic oils is caffeol, which is largely responsible for coffee's aroma and flavor.[17]

Decaffeination is often done by processing companies, and the extracted caffeine is sold to the pharmaceutical industry.[17]


Espresso brewing

Main article: Coffee preparation

The processing of coffee typically designates the agricultural and industrial processes needed to deliver whole roasted coffee beans to the consumer. Grinding the roasted coffee beans is done at a roastery, in a grocery store, or at home. It is most commonly ground at the roastery and sold to the consumer ground and packaged, though "whole-bean" coffee that is ground at home is becoming more popular, despite the extra effort required. A grind is referred to by its brewing method. "Turkish" grind, the finest, is meant for mixing straight with water, while the coarsest grinds, such as coffee percolator or French press, are at the other extreme. Midway between the extremes are the most common: "drip" and "paper filter" grinds, which are used in the most common home coffee brewing machines. The "drip" machines operate with near-boiling water passed in a slow stream through the ground coffee in a filter. The espresso method uses more advanced technology to force very hot (pressurized, not boiling) water through the ground coffee, resulting in a stronger flavor and chemical changes with more coffee bean matter in the drink. Once brewed, it may be presented in a variety of ways: on its own, with sugar, with milk or cream, hot or cold, and so on. Roasted arabica beans are also eaten plain and covered with chocolate. See the article on coffee preparation for a comprehensive list.

A number of products are sold for the convenience of consumers who do not want to prepare their own coffee . Instant coffee has been dried into soluble powder or freeze dried into granules, which can be quickly dissolved in hot water for consumption. Canned coffee is a beverage that has been popular in Asian countries for many years, particularly in Japan and South Korea. Vending machines typically sell a number of varieties of canned coffee, available both hot and cold. To match the often busy life of Korean city dwellers, companies mostly have canned coffee with a wide variety of tastes. Japanese convenience stores and groceries also have a wide availability of plastic-bottled coffee drinks, which are typically lightly sweetened and pre-blended with milk. Lastly, liquid coffee concentrate is sometimes used in large institutional situations where coffee needs to be produced for thousands of people at the same time. It is described as having a flavor about as good as low-grade robusta coffee, and costs about 10 cents a cup to produce. The machines used to process it can handle up to 500 cups an hour, or 1,000 if the water is preheated.[18]



Coffee tasting, also known as coffee cupping, is the practice of experiencing the tastes and aromas of brewed coffee. Although it is a professional practice, it can be done by anyone. The taster deeply sniffs the coffee, and then loudly slurps it so that it spreads to the back of the tongue. Then he attempts to measure aspects of the coffee's taste, specifically the body (the texture or mouthfeel, such as oiliness), acidity (a sharp and tangy feeling, like when biting into an orange), and balance (the harmony of flavours working together). Since coffee beans embody telltale flavours of the region in which they were grown, tasters may attempt to determine the coffee's origin.

Coffee with food

Coffee is generally served alongside an informal meal or as a part of breakfast. In a more formal setting, such as a restaurant, coffee usually is offered during the dessert course, after the main course.

Coffee is sometimes served as a refreshment between meals, often accompanied with a selection of cold, sweet foods. Popular choices include pastries, shortbread, cookies, muffins, and, in North America, coffee cake (so-named because it often accompanies coffee, not because it contains coffee).

Caffeine content

Depending on the type of coffee and method of preparation the caffeine content of a cup of coffee can vary greatly. However, on average the following amounts of caffeine can be expected in a single serving. A serving is 7 fluid ounces (about 207 milliliters) except for espresso.[19][20]

  • drip coffee: 115–175 mg
  • espresso: 100 mg (serving size: one shot, 1.5–2 oz)
  • brewed: 80–135 mg
  • instant: 65–100 mg
  • decaf, brewed: 3–4 mg
  • decaf, instant: 2–3 mg

Coffee and society

Social aspects of coffee

Coffeehouse in Damascus

See also: Coffeehouse for a social history of coffee, and caffè for specifically Italian traditions.
Main article: Social aspects of coffee

Coffee plays an important role in many societies throughout the world today. From the coffeehouses of the 16th century to modern day cafés, coffee has had a profound effect on the lifestyles of people from all walks of life. When it first appeared in Africa and Yemen, it was commonly used as a type of religious intoxicant. This usage in religious rites among the Sufi branch of Islam led to it being put on trial in Mecca for being a "heretic" substance much as wine was. It was briefly repressed, and was later part of a larger ban in Ottoman Turkey under an edict that led to the death of thousands of people.[21] Its early association in Europe with rebellious political activities led to its banning in England, among other places.[22]

In India the Indian Coffee Houses became an icon of the worker's struggle. This restaurant chain is now owned by the workers of ICHs, as a result of the struggle performed by the thrown-out workers from the Coffee Houses of Coffee Board. This struggle was led by famed Communist leader of India A. K. Gopalan. The ICHs became the meeting places of leftists in India later.

In Nordic countries, coffee parties are a popular, informal kind of home entertainment. In Swedish culture, coffee plays an extremely important role as a social lubricant through a process known as fika, or a leisurely coffee break — perhaps even more so than in other coffee-drinking cultures.[23]

Coffee in religions

In ancient times, coffee was initially used for spiritual reasons. At least 1,000 years ago, traders brought coffee across the Red Sea into Arabia (modern-day Yemen), where Muslim monks began cultivating the shrubs in their gardens. At first, the Arabians made wine from the pulp of the fermented coffee berries. Thus coffee became known as "Qahwah," which is the Arabic word for wine, from which the modern word coffee derives. This beverage was known as "Qishr" ("Kisher" in modern usage) and was used during religious ceremonies. Coffee became the substitute beverage in spiritual practice in place of wine where wine was forbidden.[24]

Coffee drinking was briefly prohibited to Muslims as "haraam" in the early years of the 16th century, but this was quickly overturned. Later, regarded as a "Muslim drink", it was prohibited to Ethiopian Orthodox Christians (along with khat and tobacco) up until as late as around 1900. This fact is not widely known today, as it is now considered a national drink of Ethiopia, for people of all faiths.

Another example of coffee prohibition can be found in The Church of Jesus Christ of Latter-day Saints (Latter-day Saints or Mormons), being the only major religion in the world (about 12.5 million followers world-wide) that defines a doctrine of complete coffee abstinence. The Church of Latter-Day Saints claims that it is both physically and spiritually unhealthy to consume coffee.[25] The Mormon doctrine of health given February 27, 1833 does not specifically identify caffeine as the reason for avoiding hot drinks, nor does it identify coffee by name, but was introduced by Mormon founder Joseph Smith, in a revelation called the Word of Wisdom, which includes the statement that "hot drinks are not for the belly." (Doctrine & Covenants Section 89). This was later interpreted to mean coffee or tea.

Health and pharmacology of coffee

Main article: Coffee and health

Many studies have been performed on the relationship between coffee consumption and many medical conditions, ranging from diabetes and cardiovascular disease to cancer and cirrhosis. Studies are contradictory as to whether coffee has any specific health benefits, and results are similarly conflicting with respect to negative effects of coffee consumption.[26] While some health effects are those of the caffeine, others appear to be due to other components of the coffee.

One fairly consistent finding has been the reduction of diabetes mellitus type 2 in coffee consumers, an association that cannot be explained by the caffeine content alone and indeed may be stronger in decaffeinated coffee.[27]

Recently, coffee was found to reduce the chances of developing cirrhosis of the liver: the consumption of 1 cup a day was found to reduce the chances by 20%, and 4 cups a day reduced the chances by 80%.[28]

There exists research to suggest that drinking caffeinated coffee can cause a temporary increase in the stiffening of arterial walls.[29]

Excess coffee consumption may lead to a magnesium deficiency or hypomagnesemia,[30] which may contribute to, or explain, many of the diseases or effects caused by overconsumption.[How to reference and link to summary or text]

Economics of coffee

Worldwide coffee consumption per capita and year.

Coffee being ground at a coffee shop in Chennai, India

Main article: Economics of coffee

Coffee is one of the world's most important primary commodities due to being one of the world's most popular beverages. In total, 6.7 million tonnes of coffee were produced annually in 1998–2000, and the forecast is a rise to 7 million tonnes annually by 2010.[31] Coffee also has several types of classifications used to determine environmental and labor standards.

Shade-trees in Orosí, Costa Rica. After the harvest, they are pruned

Brazil remains the largest coffee exporting nation, but in recent years the green coffee market has been flooded by large quantities of robusta beans from Vietnam.[32] Many experts believe the giant influx of cheap green coffee after the collapse of the International Coffee Agreement of 1975–1989 with Cold War pressures led to the prolonged pricing crisis from 2001 to 2004.[33] In 1997 the "c" price of coffee in New York broke US$3.00/lb, but by late 2001 it had fallen to US$0.43/lb.[34]

Robusta coffees (traded in London at much lower prices than New York's Arabica) are preferred by large industrial clients (multinational roasters, instant coffee producers, etc.) because of their lower cost.

The farmers in many parts of the Third World responded to the price crash by forming cooperatives ,allowing some members to sell their coffee for up to four times the price charged by individual farmers.[35]

Four single roaster companies buy more than 50% of all of the annual production: Kraft, Nestlé, Procter & Gamble, Sara Lee[citations needed]

. The preference of the "Big Four" coffee companies for cheap robusta is believed by many to have been a major contributing factor to the crash in coffee prices,[36] and the demand for high-quality arabica beans is only slowly recovering. After the crash, many coffee farmers in Africa, Indonesia and South and Central America lost their livelihoods, or turned to illicit crops such as coca to earn a living. The Dutch brand 'Max Havelaar' started the concept of fair trade labeling, which attempted to remedy the situation by guaranteeing coffee growers a negotiated pre-harvest price.[37] Another issue with coffee is ecological: the American Birding Association has led a campaign for sustainably harvested, shade-grown and organic coffees vs. the newer mono-cropped full-sun varieties, which lead to deforestation and loss of bird habitat.[38]

Coffee ingestion on average is about a third that of tap water in most of North America and Europe.[3] The United States consumes around six billion gallons of coffee a year.[39] In 2002 in the U.S., average coffee consumption was 22.1 gallons per person.[40]

Other uses

Coffee in art

  • Latte art involves designs in the foam of espresso-based drinks.
  • Arfé is the use of coffee as a coloring for painting or other visual effects.
  • J. S. Bach composed the humorous Coffee Cantata, about a father annoyed at his daughter's coffee addiction.


Spent coffee grounds are used as fertilizer in gardens for their acidity and high nitrogen content.[41] Many coffee companies and coffee shops give their used coffee grounds to gardeners for this purpose.[42]

Documentary films about coffee

  • Black Harvest (1992)
  • Victims of Cheap Coffee (2003)
  • Black Coffee (2005)
  • Black Gold (2006)
  • One Cup (2006)


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  2. Drug Addiction & Advice Project, Facts About Caffeine, from the Addictions Research Foundation. Retrieved on May 16, 2007.
  3. 3.0 3.1 Villanueva1, Cristina M., Cantor, Kenneth P.; King, Will D.; Jaakkola, Jouni J. K.; Cordier, Sylvaine; Lynch, Charles F.; Porru, Stefano; Kogevinas, Manolis (2006). Total and specific fluid consumption as determinants of bladder cancer risk. International Journal of Cancer 118 (8): 2040–2047.
  4. FAOSTAT Agriculture Data. United Nations Food and Agriculture Organization. URL accessed on 2005-10-31.
  5. "Definition of Coffee" in Merriam-Webster Online Dictionary
  6. Coffee:Oxford English Dictionary in The Oxford English Dictionary Online
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  8. Process for improving the quality of Robusta coffee - US Patent 5019413. URL accessed on 2006-08-26.
  9. Dictionary Version 1.0.1 (1.0.1) Copyright © 2005 Apple Computer, Inc.
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  11. pH Scale: Some Common Solutions - Chart - MSN Encarta. URL accessed on 2006-07-23.
  12. The Perfect Cup, by Timothy James Castle
  13. Coffee: A Guide to Buying Brewing and Enjoying, 5th Edition, by Kenneth Davids
  14. S. Hamon, M. Noirot, and F. Anthony, Developing a coffee core collection using the principal components score strategy with quantitative data (PDF), Core Collections of Plant Genetic Resources, 1995.
  15. Feature Article: Peaberry Coffee. URL accessed on 2006-11-10.
  16. 16.0 16.1 16.2 Kummer, Corby. The Joy of Coffee: The Essential Guide to Buying, Brewing, and Enjoying, Houghton Mifflin, August 19, 2003. ISBN 978-0618302406.
  17. 17.0 17.1 Dobelis, Inge N., Ed.: Magic and Medicine of Plants. Pleasantville: The Reader’s Digest Association, Inc., 1986. Pages 370-371.
  18. Regarding liquid coffee concentrate: Wall Street Journal, March 21, 2005, page C4, Commodities Report
  19. Coffee and Caffeine's Frequently Asked Questions from the alt.drugs.caffeine,, Newsgroups, January 7, 1998
  20. Bunker, M. L., McWilliams, M. (January 1979). Caffeine content of common beverages. J. Am. Diet. Assoc. 74: 28-32.
  21. Hopkins, Kate Food Stories: The Sultan's Coffee Prohibition. URL accessed on 2006-09-12.
  22. Allen, Stewart. "The Devil's Cup".
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  25. Church of Jesus Christ of Latter-day Saints, Who Are the Mormons?,
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  27. Pereira MA, Parker ED, Folsom AR. (2006). Coffee consumption and risk of type 2 diabetes mellitus.. Arch Intern Med 166 (12): 1311–1316. PMID 16801515.
  28. Klatsky, Arthur L., Morton, Cynthia, Udaltsova, Natalia, Friedman, Gary D. (12 June 2006). Coffee, Cirrhosis, and Transaminase Enzymes. Archives of Internal Medicine 166 (11): 1190–1195.
  30. The multifaceted and widespread pathology of magnesium deficiency
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  35. Al Jazeera. URL accessed on 2007-01-25.
  36. CoffeeGeek - So You Say There's a Coffee Crisis. URL accessed on 2006-08-26.
  37. Fair Trade Coffee. URL accessed on 2006-08-26.
  38. Song Bird Coffee. Thanksgiving Coffee Company.
  40. Bottled water pours past competition - Brief Article DSN Retailing Today - Find Articles. URL accessed on 2006-07-23.
  41. Kathy LaLiberte. Gardner's Tips: Composting with Coffee. Gardner's Supply Company. URL accessed on 2007-04-18.
  42. Composting with Coffee Grounds - Page on official Starbucks website describing their composting efforts. URL accessed on 2007-01-08.


  • Pendergrast, Mark. Uncommon Grounds: The History of Coffee and How It Transformed Our World, Basic Books, 1999. ISBN 0-465-05467-6
  • Rauwolf, Léonard. Reise in die Morgenlander. (German)
  • United Nations Food and Agriculture Organization. FAOSTAT Agriculture Data Accessed October 31, 2005.
  • Villanueva1, et al. (2006) Total and specific fluid consumption as determinants of bladder cancer risk. International Journal of Cancer 118(8):2040–2047

External links

Wikimedia Commons has media related to:
Wikiquote has a collection of quotations related to:
Wikibooks Cookbook has an article on
  • Coffee & Conservation - Many resources on sustainable coffee, including reviews, especially shade coffee and biodiversity
  • Coffee and caffeine health information - A collection of peer reviewed & journal published studies on coffee health benefits is evaluated, cited & summarized.
  • Benjamin Joffe-Walt and Oliver Burkeman, The Guardian, 16 September 2005, "Coffee trail" - from Ethiopian village of Choche to London coffee shop
  • Coffee on a Grande Scale - Article about the biology, chemistry, and physics of coffee production
  • This is Coffee - Short tribute to coffee in the form of a documentary film (1961), made by "The Coffee Brewing Institute". The movie includes some do's and don'ts of making "the perfect cup of coffee" and an overview of different ways to enjoy coffee throughout the world.



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