Coffee is a brewed beverage prepared from the roasted seeds of several species of an evergreen shrub of the genus Coffea. The two most common sources of coffee beans are the highly regarded Coffea arabica, and the "robusta" form of the hardier Coffea canephora. The latter is resistant to the coffee leaf rust (Hemileia vastatrix), but has a more bitter taste. Coffee plants are cultivated in more than 70 countries, primarily in equatorial Latin America, Southeast Asia, and Africa. Once ripe, coffee "berries" are picked, processed, and dried to yield the seeds inside. The seeds are then roasted to varying degrees, depending on the desired flavor, before being ground and brewed to create coffee.
Coffee is slightly acidic (pH 5.0–5.1) and can have a stimulating effect on humans because of its caffeine content. It is one of the most popular drinks in the world. It can be prepared and presented in a variety of ways. The effect of coffee on human health has been a subject of many studies; however, results have varied in terms of coffee's relative benefit. The majority of recent research suggests that moderate coffee consumption is benign or mildly beneficial in healthy adults. However, coffee can worsen the symptoms of conditions such as anxiety, largely due to the caffeine and diterpenes it contains.
Coffee cultivation first took place in southern Arabia; the earliest credible evidence of coffee-drinking appears in the middle of the 15th century in the Sufi shrines of Yemen. In East Africa and Yemen, coffee was used in native religious ceremonies. As these ceremonies conflicted with the beliefs of the Christian church, the Ethiopian Church banned the secular consumption of coffee until the reign of Emperor Menelik II. The beverage was also banned in Ottoman Turkey during the 17th century for political reasons and was associated with rebellious political activities in Europe.
An important export commodity, coffee was the top agricultural export for twelve countries in 2004, and it was the world's seventh-largest legal agricultural export by value in 2005. Green (unroasted) coffee is one of the most traded agricultural commodities in the world. Some controversy is associated with coffee cultivation and its impact on the environment. Consequently, organic coffee is an expanding market.
- 1 Etymology
- 2 History
- 3 Biology
- 4 Cultivation
- 5 Production
- 6 Sale and distribution
- 7 Health and pharmacology
- 8 Caffeine content
- 9 Social and culture
- 10 See also
- 11 References
- 12 External links
The first reference to coffee in the English language is in the form chaoua, dated to 1598. In English and other European languages, "coffee" descends from the Italian word caffè. In turn, caffè derives from kahve, the Ottoman Turkish word for coffee, which is itself derived from the Arabic: قهوة, qahwah. Arab lexicographers maintain that qahwah originally referred to a type of wine, and gave its etymology, in turn, to the verb قها qahā, signifying "to have no appetite", since this beverage was thought to dull one's hunger.
Other proposed etymologies include tracing coffee to the word "quwwa," Arabic for power, or to the region of Kaffa in Ethiopia. For the latter etymology, some hold Arabs named it after the Kaffa region, but others with "equally little authority" say the region was named after the drink.
According to legend, ancestors of today's Oromo people were believed to have been the first to recognize the energizing effect of the coffee plant, though no direct evidence has been found indicating where in Africa coffee grew or who among the native populations might have used it as a stimulant or even known about it, earlier than the 17th century. The story of Kaldi, the 9th-century Ethiopian goatherder who supposedly discovered coffee when his goats behaved strangely after eating from a coffee plant, did not appear in writing until 1671 and is probably apocryphal. The original domesticated coffee plant is said to have been from Harar in Ethiopia.
Other accounts attribute the discovery of coffee to Sheik Omar. According to the ancient chronicle (preserved in the Abd-Al-Kadir manuscript), Omar, who was known for his ability to cure the sick through prayer, was once exiled from Mocha, Yemen to a desert cave near Ousab. Starving, Omar chewed berries from nearby shrubbery, but found them to be bitter. He tried roasting the seeds to improve the flavor, but they became hard. He then tried boiling them to soften the seed, which resulted in a fragrant brown liquid. Upon drinking the liquid Omar was revitalized and sustained for days. As stories of this "miracle drug" reached Mocha, Omar was asked to return and was made a saint. From Ethiopia, the coffee plant was introduced into the Arab world through Egypt and Yemen.
The earliest credible evidence of either coffee drinking or knowledge of the coffee tree appears in the middle of the 15th century, in the Sufi Muslim monasteries around Mocha in Yemen. It was here in Arabia that coffee seeds were first roasted and brewed, in a similar way to how it is now prepared. By the 16th century, it had reached the rest of the Middle East, Persia, Turkey, and northern Africa. Coffee seeds were first exported from Ethiopia to Yemen. Yemeni traders brought coffee back to their homeland and began to cultivate the seed. The first coffee smuggled out of the Middle East was by Sufi Baba Budan from Yemen to India in 1670. Before then, all exported coffee was boiled or otherwise sterilised. Portraits of Baba Budan depict him as having smuggled seven coffee seeds by strapping them to his chest. The first plants grown from these smuggled seeds were planted in Mysore. Coffee then spread to Italy, and to the rest of Europe, to Indonesia, and to the Americas.
A beverage as black as ink, useful against numerous illnesses, particularly those of the stomach. Its consumers take it in the morning, quite frankly, in a porcelain cup that is passed around and from which each one drinks a cupful. It is composed of water and the fruit from a bush called bunnu.—Léonard Rauwolf, Reise in die Morgenländer (in German)
From the Middle East, coffee spread to Italy. The thriving trade between Venice and North Africa, Egypt, and the Middle East brought many goods, including coffee, to the Venetian port. From Venice, it was introduced to the rest of Europe. Coffee became more widely accepted after it was deemed a Christian beverage by Pope Clement VIII in 1600, despite appeals to ban the "Muslim drink." The first European coffee house opened in Italy in 1645.
The Dutch East India Company was the first to import coffee on a large scale. The Dutch later grew the crop in Java and Ceylon. The first exports of Indonesian coffee from Java to the Netherlands occurred in 1711.
Through the efforts of the British East India Company, coffee became popular in England as well. Oxford's Queen's Lane Coffee House, established in 1654, is still in existence today. Coffee was introduced in France in 1657, and in Austria and Poland after the 1683 Battle of Vienna, when coffee was captured from supplies of the defeated Turks.
When coffee reached North America during the Colonial period, it was initially not as successful as it had been in Europe as alcoholic beverages remained more popular. During the Revolutionary War, the demand for coffee increased so much that dealers had to hoard their scarce supplies and raise prices dramatically; this was also due to the reduced availability of tea from British merchants, and a general resolution among many Americans to avoid drinking tea following the 1773 Boston Tea Party.
After the War of 1812, during which Britain temporarily cut off access to tea imports, the Americans' taste for coffee grew. Coffee consumption declined in England, giving way to tea during the 18th century. The latter beverage was simpler to make, and had become cheaper with the British conquest of India and the tea industry there. During the Age of Sail, seamen aboard ships of the British Royal Navy made substitute coffee by dissolving burnt bread in hot water.
The Frenchman Gabriel de Clieu brought a coffee plant to the French territory of Martinique in the Caribbean, from which much of the world's cultivated arabica coffee is descended. Coffee thrived in the climate and was conveyed across the Americas. The territory of Santo Domingo (now Haiti) saw coffee cultivated from 1734, and by 1788 it supplied half the world's coffee. The conditions that the slaves worked in on coffee plantations were a factor in the soon to follow Haitian Revolution. The coffee industry never fully recovered there.
Meanwhile, coffee had been introduced to Brazil in 1727, although its cultivation did not gather momentum until independence in 1822. After this time, massive tracts of rainforest were cleared first from the vicinity of Rio and later São Paulo for coffee plantations. Cultivation was taken up by many countries in Central America in the latter half of the 19th century, and almost all involved the large-scale displacement and exploitation of the indigenous people. Harsh conditions led to many uprisings, coups and bloody suppression of peasants. The notable exception was Costa Rica, where lack of ready labor prevented the formation of large farms. Smaller farms and more egalitarian conditions ameliorated unrest over the 19th and 20th centuries.
Coffee has become a vital cash crop for many developing countries. Over one hundred million people in developing countries have become dependent on coffee as their primary source of income. It has become the primary export and backbone for African countries like Uganda, Burundi, Rwanda, and Ethiopia, as well as many Central American countries.
Several species of shrub of the genus Coffea produce the berries from which coffee is extracted. The two main species commercially cultivated are Coffea canephora (predominantly a form known as 'robusta') and C. arabica. C. arabica, the most highly regarded species, is native to the southwestern highlands of Ethiopia and the Boma Plateau in southeastern Sudan and possibly Mount Marsabit in northern Kenya. C. canephora is native to western and central Subsaharan Africa, from Guinea to the Uganda and southern Sudan. Less popular species are C. liberica, C. stenophylla, C. mauritiana, and C. racemosa.
All coffee plants are classified in the large family Rubiaceae. They are evergreen shrubs or small trees that may grow 5 m (15 ft) tall when unpruned. The leaves are dark green and glossy, usually 10–15 cm (4–6 in) long and 6 cm (2.4 in) wide, simple, entire, and opposite. Petioles of opposite leaves fuse at base to form interpetiolar stipules, characteristic of Rubiaceae. The flowers are axillary, and clusters of fragrant white flowers bloom simultaneously. Gynoecium consists of inferior ovary, also characteristic of Rubiaceae. Flowers followed by oval berries of about 1.5 cm (0.6 in). Green when immature, they ripen to yellow, then crimson, before turning black on drying. Each berry usually contains two seeds, but 5–10% of the berries have only one; these are called peaberries. Arabica berries ripen in six to eight months, while robusta take nine to eleven months.
Coffea arabica is predominantly self-pollinating, and as a result the seedlings are generally uniform and vary little from their parents. In contrast, Coffea canephora, and C. liberica are self-incompatible and require outcrossing. This means that useful forms and hybrids must be propagated vegetatively. Cuttings, grafting, and budding are the usual methods of vegetative propagation. On the other hand, there is great scope for experimentation in search of potential new strains.
The traditional method of planting coffee is to place 20 seeds in each hole at the beginning of the rainy season. This method loses about 50% of the seeds' potential, as about half fail to sprout. A more effective method of growing coffee, used in Brazil, is to raise seedlings in nurseries that are then planted outside at six to twelve months. Coffee is often intercropped with food crops, such as corn, beans, or rice during the first few years of cultivation as farmers become familiar with its requirements.
Of the two main species grown, arabica coffee (from C. arabica) is generally more highly regarded than robusta coffee (from C. canephora); robusta tends to be bitter and have less flavor but better body than arabica. For these reasons, about three-quarters of coffee cultivated worldwide is C. arabica. Robusta strains also contain about 40–50% more caffeine than arabica. For this reason, it is used as an inexpensive substitute for arabica in many commercial coffee blends. Good quality robusta seeds are used in traditional Italian espresso blends to provide a full-bodied taste and a better foam head (known as crema).
However, Coffea canephora is less susceptible to disease than C. arabica and can be cultivated in lower altitudes and warmer climates where C. arabica will not thrive. The robusta strain was first collected in 1890 from the Lomani River, a tributary of the Congo River, and was conveyed from Zaire (now the Democratic Republic of Congo) to Brussels to Java around 1900. From Java, further breeding resulted in the establishment of robusta plantations in many countries. In particular, the spread of the devastating coffee leaf rust (Hemileia vastatrix), to which C. arabica is vulnerable, hastened the uptake of the resistant robusta. Coffee leaf rust is found in virtually all countries that produce coffee.
Over 900 species of insect have been recorded as pests of coffee crops worldwide. Of these, over a third are beetles, and over a quarter are bugs. Some 20 species of nematodes, 9 species of mites, several snails and slugs also attack the crop. Birds and rodents sometimes eat coffee berries but their impact is minor compared to invertebrates. In general, arabica is the more sensitive species to invertebrate predation overall. Each part of the coffee plant is assailed by different animals. Nematodes attack the roots, and borer beetles burrow into stems and woody material, the foliage is attacked by over 100 species of larvae (caterpillars) of butterflies and moths.
Mass spraying of insecticides has often proven disastrous, as the predators of the pests are more sensitive than the pests themselves. Instead, integrated pest management has developed, using techniques such as targeted treatment of pest outbreaks, and managing crop environment away from conditions favouring pests. Branches infested with scale are often cut and left on the ground, which promotes scale parasites to not only attack the scale on the fallen branches but in the plant as well.
The 2-mm-long coffee berry borer beetle is the most damaging insect pest to the world’s coffee industry, destroying up to 50 percent or more of the coffee berries on plantations in most coffee-producing countries. The adult female beetle nibbles a single tiny hole in a coffee berry and lays 35 to 50 eggs. Inside, the offspring grow, mate, and then emerge from the commercially ruined berry to disperse, repeating the cycle. Pesticides are mostly ineffective because the beetle juveniles are protected inside the berry nurseries, but they are vulnerable to predation by birds when they emerge. When groves of trees are nearby, the American Yellow Warbler, Rufous-capped Warbler and other insectivorous birds have been shown to reduce by 50 percent the number of coffee berry borer beetles in Costa Rica coffee plantations.
|Rank||Country||Tonnes||Bags x1000||Market share|
|Top 5 producers||5,162,040||86,034||65.6%|
|14||Ivory Coast[note 1]||96,000||1,600||1.2%|
|15||Papua New Guinea[note 2]||84,900||1,415||1.1%|
|19||Democratic Republic of the Congo||63,360||1,056||0,80%|
In 2011 Brazil was the world leader in production of green coffee, followed by Vietnam, Indonesia and Colombia. Arabica coffee seeds are cultivated in Latin America, eastern Africa, Arabia, or Asia. Robusta coffee seeds are grown in western and central Africa, throughout southeast Asia, and to some extent in Brazil.
Seeds from different countries or regions can usually be distinguished by differences in flavor, aroma, body, and acidity. These taste characteristics are dependent not only on the coffee's growing region, but also on genetic subspecies (varietals) and processing. Varietals are generally known by the region in which they are grown, such as Colombian, Java and Kona.
Originally, coffee farming was done in the shade of trees that provided a habitat for many animals and insects. Remnant forest trees were used for this purpose, but many species have been planted as well. These include leguminous trees of the genera Acacia, Albizia, Cassia, Erythrina, Gliricidia, Inga, and Leucaena, as well as the nitrogen-fixing non-legume sheoaks of the genus Casuarina, and the silky oak Grevillea robusta.
This method commonly referred to as the traditional shaded method, or "shade-grown". Starting in the 1970s, many farmers switched their production method to sun cultivation, in which coffee is grown in rows under full sun with little or no forest canopy. This causes berries to ripen more rapidly and bushes to produce higher yields, but requires the clearing of trees and increased use of fertilizer and pesticides, which damage the environment and cause health problems.
Unshaded coffee plants grown with fertilizer yield the most coffee, although unfertilized shaded crops generally yield more than unfertilized unshaded crops: the response to fertilizer is much greater in full sun. Although traditional coffee production causes berries to ripen more slowly and produce lower yields, the quality of the coffee is allegedly superior. In addition, the traditional shaded method provides living space for many wildlife species. Proponents of shade cultivation say environmental problems such as deforestation, pesticide pollution, habitat destruction, and soil and water degradation are the side effects of the practices employed in sun cultivation.
The American Birding Association, Smithsonian Migratory Bird Center, National Arbor Day Foundation, and the Rainforest Alliance have led a campaign for 'shade-grown' and organic coffees, which can be sustainably harvested. Shaded coffee cultivation systems show greater biodiversity than full-sun systems, and those more distant from continuous forest compare rather poorly to undisturbed native forest in terms of habitat value for some bird species.
Another issue concerning coffee is its use of water. According to New Scientist, using industrial farming practices, it takes about 140 liters (37 U.S. gal) of water to grow the coffee seeds needed to produce one cup of coffee, and the coffee is often grown in countries where there is a water shortage, such as Ethiopia.
By using sustainable agriculture methods, the amount of water usage can be dramatically reduced, while retaining comparable yields. For comparison, the United States Geological Survey reports that one egg requires an input of 454 liters (120 U.S. gal) of water; one serving of milk requires an input of 246 liters (65 U.S. gal) of water; one serving of rice requires an input of 132 liters (35 U.S. gal) of water; and one glass of wine requires an input of 120 liters (32 U.S. gal) of water.
Coffee grounds may be used for composting or as a mulch. They are especially appreciated by worms and acid-loving plants such as blueberries. Some commercial coffee shops run initiatives to make better use of these grounds, including Starbucks' "Grounds for your Garden" project, and community sponsored initiatives such as "Ground to Ground".
Coffee berries and their seeds undergo several processes before they become the familiar roasted coffee. Berries have been traditionally selectively picked by hand; a labor-intensive method, it involves the selection of only the berries at the peak of ripeness. More commonly, crops are strip picked, where all berries are harvested simultaneously regardless of ripeness by person or machine. After picking, green coffee is processed by one of two methods—the dry process method, simpler and less labor-intensive as the berries can be strip picked, and the wet process method, which incorporates fermentation into the process and yields a mild coffee.
Then they are sorted by ripeness and color and most often the flesh of the berry is removed, usually by machine, and the seeds are fermented to remove the slimy layer of mucilage still present on the seed. When the fermentation is finished, the seeds are washed with large quantities of fresh water to remove the fermentation residue, which generates massive amounts of coffee wastewater. Finally, the seeds are dried.
The best (but least used) method of drying coffee is using drying tables. In this method, the pulped and fermented coffee is spread thinly on raised beds, which allows the air to pass on all sides of the coffee, and then the coffee is mixed by hand. In this method the drying that takes place is more uniform, and fermentation is less likely. Most African coffee is dried in this manner and certain coffee farms around the world are starting to use this traditional method.
Next, the coffee is sorted, and labeled as green coffee. Another way to let the coffee seeds dry is to let them sit on a concrete patio and rake over them in the sunlight. Some companies use cylinders to pump in heated air to dry the coffee seeds, though this is generally in places where the humidity is very high.
Some coffee undergoes a peculiar process, such as kopi luwak. It is made from the seeds of coffee berries which have been eaten by the Asian Palm Civet and other related civets, passing through its digestive tract. This process resulted in coffee seeds with much less bitterness, widely noted as the most expensive coffee in the world with prices reaching $160 per pound.
The next step in the process is the roasting of the green coffee. Coffee is usually sold in a roasted state, and with rare exceptions all coffee is roasted before it is consumed. It can be sold roasted by the supplier, or it can be home roasted. The roasting process influences the taste of the beverage by changing the coffee seed both physically and chemically. The seed decreases in weight as moisture is lost and increases in volume, causing it to become less dense. The density of the seed also influences the strength of the coffee and requirements for packaging.
The actual roasting begins when the temperature inside the seed reaches approximately 200 °C (392 °F), though different varieties of seeds differ in moisture and density and therefore roast at different rates. During roasting, caramelization occurs as intense heat breaks down starches, changing them to simple sugars that begin to brown, which alters the color of the seed.
Sucrose is rapidly lost during the roasting process and may disappear entirely in darker roasts. During roasting, aromatic oils and acids weaken, changing the flavor; at 205 °C (401 °F), other oils start to develop. One of these oils, caffeol, is created at about 200 °C (392 °F), which is largely responsible for coffee's aroma and flavor.
Grading the roasted seeds
Depending on the color of the roasted seeds as perceived by the human eye, they will be labeled as light, medium light, medium, medium dark, dark, or very dark. A more accurate method of discerning the degree of roast involves measuring the reflected light from roasted seeds illuminated with a light source in the near infrared spectrum. This elaborate light meter uses a process known as spectroscopy to return a number that consistently indicates the roasted coffee's relative degree of roast or flavor development.
The degree of roast has an effect upon coffee flavor and body. Darker roasts are generally bolder because they have less fiber content and a more sugary flavor. Lighter roasts have a more complex and therefore perceived stronger flavor from aromatic oils and acids otherwise destroyed by longer roasting times. Roasting does not alter the amount of caffeine in the bean, but does give less caffeine when the beans are measured by volume because the beans expand during roasting.
A small amount of chaff is produced during roasting from the skin left on the seed after processing. Chaff is usually removed from the seeds by air movement, though a small amount is added to dark roast coffees to soak up oils on the seeds.
Decaffeination may also be part of the processing that coffee seeds undergo. Seeds are decaffeinated when they are still green. Many methods can remove caffeine from coffee, but all involve either soaking the green seeds in hot water (often called the "Swiss water process") or steaming them, then using a solvent to dissolve caffeine-containing oils. Decaffeination is often done by processing companies, and the extracted caffeine is usually sold to the pharmaceutical industry.
Coffee is best stored in an airtight container made of ceramic, glass, or non-reactive metal. Higher quality prepackaged coffee usually has a one-way valve which prevents air from entering while allowing the coffee to release gases. Coffee freshness and flavor is preserved when it is stored away from moisture, heat, and light. The ability of coffee to absorb strong smells from food means that it should be kept away from such smells. Storage of coffee in the refrigerator is not recommended due to the presence of moisture which can cause deterioration. Exterior walls of buildings which face the sun may heat the interior of a home, and this heat may damage coffee stored near such a wall. Heat from nearby ovens also harms stored coffee.
In 1931, a method of packing coffee in a sealed vacuum in cans was introduced. The roasted coffee was packed and then 99% of the air was removed, allowing the coffee to be stored indefinitely until the can was opened. Today this method is in mass use for coffee in a large part of the world.
Coffee seeds must be ground and brewed to create a beverage. The criteria for choosing a method include flavor and economy. Almost all methods of preparing coffee require that the seeds be ground and then mixed with hot water long enough to allow the flavor to emerge but not so long as to draw out bitter compounds. The liquid can be consumed after the spent grounds are removed. Brewing considerations include the fineness of grind, the way in which the water is to extract the flavor, additional flavorings such as sugar, milk, and spices, and the technique to be used to separate spent grounds. Ideal holding temperatures range from 85–88 °C (185–190 °F) to as high as 93 °C (199 °F) and the ideal serving temperature is 68 to 79 °C (154 to 174 °F).
The roasted coffee seeds may be ground at a roastery, in a grocery store, or in the home. Most coffee is roasted and ground at a roastery and sold in packaged form, though roasted coffee seeds can be ground at home immediately before consumption. It is also possible, though uncommon, to roast raw seeds at home.
The choice of brewing method depends to some extent on the degree to which the coffee seeds have been roasted. Lighter roasted coffee tends to be used for filter coffee as the combination of method and roast style results in higher acidity, complexity, and clearer nuances[clarification needed]. Darker roasted coffee is used for espresso because the machine naturally extracts more dissolved solids, causing lighter coffee to become too acidic.
Coffee seeds may be ground in several ways. A burr grinder uses revolving elements to shear the seed; a blade grinder cuts the seeds with blades moving at high speed; and a mortar and pestle crushes the seeds. For most brewing methods a burr grinder is deemed superior because the grind is more even and the grind size can be adjusted.
The type of grind is often named after the brewing method for which it is generally used. Turkish grind is the finest grind, while coffee percolator or French press are the coarsest grinds. The most common grinds are between these two extremes: a medium grind is used in most home coffee-brewing machines.
Coffee may be brewed by several methods. It may be boiled, steeped, or pressurized.
Brewing coffee by boiling was the earliest method, and Turkish coffee is an example of this method. It is prepared by grinding or pounding the seeds to a fine powder, then adding it to water and bringing it to the boil for no more than an instant in a pot called a cezve or, in Greek, a bríki. This produces a strong coffee with a layer of foam on the surface and sediment (which is not meant for drinking) settling at the bottom of the cup.
Coffee percolators and automatic coffeemakers brew coffee using gravity. In an automatic coffeemaker, hot water drips onto coffee grounds that are held in a paper, plastic, or perforated metal coffee filter, allowing the water to seep through the ground coffee while extracting its oils and essences. The liquid drips through the coffee and the filter into a carafe or pot, and the spent grounds are retained in the filter.
In a percolator, boiling water is forced into a chamber above a filter by steam pressure created by boiling. The water then seeps through the grounds, and the process is repeated until terminated by removing from the heat, by an internal timer, or by a thermostat that turns off the heater when the entire pot reaches a certain temperature.
Coffee may be brewed by steeping in a device such as a French press (also known as a cafetière, coffee press or coffee plunger). Ground coffee and hot water are combined in a cylindrical vessel and left to brew for a few minutes. A circular filter which fits tightly in the cylinder fixed to a plunger is then pushed down from the top to force the grounds to the bottom. The filter retains the grounds at the bottom as the coffee is poured from the container. Because the coffee grounds are in direct contact with the water, all the coffee oils remain in the liquid, making it a stronger beverage. This method of brewing leaves more sediment than in coffee made by an automatic coffee machine. Supporters of the French press method point out that the sediment issue can be minimized by using the right type of grinder: they claim that a rotary blade grinder cuts the coffee bean into a wide range of sizes, including a fine coffee dust that remains as sludge at the bottom of the cup, while a burr grinder uniformly grinds the beans into consistently-sized grinds, allowing the coffee to settle uniformly and be trapped by the press. 95% of the caffeine is released from the coffee seeds within the first minute of brewing.
The espresso method forces hot pressurized and vaporized water through ground coffee. As a result of brewing under high pressure (ideally between 9–10 atm), the espresso beverage is more concentrated (as much as 10 to 15 times the quantity of coffee to water as gravity-brewing methods can produce) and has a more complex physical and chemical constitution. A well-prepared espresso has a reddish-brown foam called crema that floats on the surface. Other pressurized water methods include the moka pot and vacuum coffee maker.
Once brewed, coffee may be served in a variety of ways. Drip-brewed, percolated, or French-pressed/cafetière coffee may be served as white coffee with a dairy product such as milk or cream, or dairy substitute, or as black coffee with no such addition. It may be sweetened with sugar or artificial sweetener. When served cold, it is called iced coffee.
Espresso-based coffee has a variety of possible presentations. In its most basic form, an espresso is served alone as a shot or short black, or with hot water added, and is known as Caffè Americano. A long black is made by pouring a double espresso into an equal portion of water, retaining the crema, unlike Caffè Americano. Milk is added in various forms to an espresso: steamed milk makes a caffè latte, equal parts steamed milk and milk froth make a cappuccino, and a dollop of hot foamed milk on top creates a caffè macchiato. The use of steamed milk to form patterns such as hearts or maple leaves is referred to as latte art.
Coffee can also be incorporated with alcohol to produce a variety of beverages: it is combined with whiskey in Irish coffee, and it forms the base of alcoholic coffee liqueurs such as Kahlúa and Tia Maria. Coffee is also sometimes used in the brewing process of darker beers, such as a stout or porter.
A number of products are sold for the convenience of consumers who do not want to prepare their own coffee.
Instant coffee is dried into soluble powder or freeze-dried into granules that can be quickly dissolved in hot water. Originally invented in 1907, it rapidly gained in popularity in many countries in the post-war period, with Nescafé being the most popular product. Many consumers determined that the convenience in preparing a cup of instant coffee more than made up for a perceived inferior taste. Paralleling (and complementing) the rapid rise of instant coffee was the coffee vending machine, invented in 1947 and multiplying rapidly through the 1950s.
Canned coffee has been popular in Asian countries for many years, particularly in China, Japan, South Korea, and Taiwan. Vending machines typically sell varieties of flavored canned coffee, much like brewed or percolated coffee, available both hot and cold. Japanese convenience stores and groceries also have a wide availability of bottled coffee drinks, which are typically lightly sweetened and pre-blended with milk. Bottled coffee drinks are also consumed in the United States.
Liquid coffee concentrates are 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¢ a cup to produce. The machines can process up to 500 cups an hour, or 1,000 if the water is preheated.
Sale and distribution
Coffee ingestion on average is about a third of that of tap water in North America and Europe. Worldwide, 6.7 million metric tons of coffee were produced annually in 1998–2000, and the forecast is a rise to seven million metric tons annually by 2010.
Brazil remains the largest coffee exporting nation, but Vietnam tripled its exports between 1995 and 1999 and became a major producer of robusta seeds. Indonesia is the third-largest coffee exporter overall and the largest producer of washed arabica coffee. Organic Honduran coffee is a rapidly growing emerging commodity owing to the Honduran climate and rich soil.
In 2013 The Seattle Times reported that global coffee prices have dropped more than 50 percent year-over-year. In Thailand Black Ivory coffee beans are fed to elephants, whose digestive enzymes remove much of the beans bitter taste. After being collected from their dung, these beans can sell for as much as $1,100 a kilogram making it the most expensive blend in the world. Another blend, Kopi Luwak is made through a similar process after being digested by the Asian Palm Civet; but it is sold for somewhat less at 100-$600 a pound.
Coffee is bought and sold by roasters, investors, and price speculators as a tradable commodity in commodity markets and exchange-traded funds. Coffee futures contracts for Grade 3 washed arabicas are traded on the New York Mercantile Exchange under ticker symbol KC, with contract deliveries occurring every year in March, May, July, September, and December. Coffee is an example of a product that has been susceptible to significant commodity futures price variations.
Higher and lower grade arabica coffees are sold through other channels. Futures contracts for robusta coffee are traded on the London International Financial Futures and Options Exchange and, since 2007, on the New York IntercontinentalExchange. Coffee has been described by many, including historian Mark Pendergrast, as the world's "second most legally traded commodity." However, this claim has been recently refuted by Pendergrast among others after further research.
Health and pharmacology
||This section needs more medical references for verification or relies too heavily on primary sources. (August 2013)|
Method of action
The primary psychoactive chemical in coffee is caffeine, an adenosine antagonist that is known for its stimulant effects. Coffee also contains the monoamine oxidase inhibitors β-carboline and harmane, which may contribute to its psychoactivity.
In a healthy liver, caffeine is mostly broken down by the hepatic microsomal enzymatic system. The excreted metabolites are mostly paraxanthines—theobromine and theophylline—and a small amount of unchanged caffeine. Therefore, the metabolism of caffeine depends on the state of this enzymatic system of the liver.
Extensive scientific research has been conducted to examine the relationship between coffee consumption and an array of medical conditions. The general consensus in the medical community is that moderate regular coffee drinking in healthy individuals is either essentially benign or mildly beneficial. In 2012, the National Institutes of Health–AARP Diet and Health Study analysed the relationship between coffee drinking and mortality. They found that the amount of coffee consumed correlated negatively with risk of death, and that those who drank any coffee lived longer than those who did not. However the authors noted, "whether this was a causal or associational finding cannot be determined from our data." A similar study with similar results was published in the New England Journal of Medicine in 2012. Researchers involved in an ongoing 22-year study by the Harvard School of Public Health stated that "the overall balance of risks and benefits [of coffee consumption] are on the side of benefits."
Findings have also been contradictory as to whether coffee has any specific health benefits, and results are similarly conflicting regarding the potentially harmful effects of coffee consumption. Furthermore, results and generalizations are complicated by differences in age, gender, health status, and serving size.
According to Cancer Research UK, the results of the large-scale study published in 2012 clarified the evidence of the effect of coffee drinking on cancer, and that evidence beforehand had been conflicting. They say the study showed that drinking coffee "had no effect on the risk of dying from cancer."
Other studies suggest coffee consumption reduces the risk of Alzheimer's disease, dementia, Parkinson's disease, heart disease, diabetes mellitus type 2, non-alcoholic fatty liver disease, cirrhosis, and gout.
The fact that decaffeinated coffee also exhibits preventative effects against diseases such as prostate cancer and type 2 diabetes suggests that coffee's health benefits are not solely a product of its caffeine content. Specifically, the antidiabetic effect of caffeine has been attributed to caffeic acid and chlorogenic acid.
The presence of antioxidants in coffee has been shown to prevent free radicals from causing cell damage. Evidence suggests that roasted coffee has a stronger antioxidant effect than green coffee.
Coffee is no longer thought to be a risk factor for coronary heart disease. A 2012 meta-analysis concluded that people who drank moderate amounts of coffee had a lower rate of heart failure, with the biggest effect found for those who drank more than four cups a day.  Moreover, habitual coffee consumption is associated with improved vascular function. In a ten year study among 50,739 US women (mean age, 63 years) free of depressive symptoms at baseline (in 1996), coffee consumption was negatively correlated with risk of developing depression. A review published in 2004 indicated a negative correlation between suicide rates and coffee consumption. It was suggested that the action of caffeine in blocking the inhibitory effects of adenosine on dopamine nerves in the brain reduced feelings of depression. Coffee consumption is also associated with improved endothelial function. Coffee extracts have been shown to inhibit 11beta-hydroxysteroid dehydrogenase type 1, enzyme which converts cortisone to cortisol and is a current pharmaceutical target for the treatment of diabetes type 2 and the metabolic syndrome.
Excessive amounts of coffee can cause very unpleasant and even life-threatening adverse effects. Coffee's adverse effects are more common when taken in excess. Many of coffee's health risks are due to its caffeine content and can therefore be avoided by drinking decaffeinated coffee.
Oily components called diterpenes are present in unfiltered coffee and coffee brewed using metal filters, but not in coffee brewed using paper filters. The two diterpenes present in coffee, kahweol and cafestol, have been associated with increased risk of coronary heart disease via elevation of low-density lipoprotein (LDL) levels in blood.
Elderly individuals with a depleted enzymatic system do not tolerate coffee with caffeine well. Moderate amounts of coffee (50–100 mg of caffeine or 5–10 g of coffee powder a day) are well tolerated by most elderly people.
Coffee consumption can lead to iron deficiency anemia by interfering with iron absorption, especially in mothers and infants. Coffee's interference with iron absorption is due to the polyphenols it contains. However, excess iron is carcinogenic to the liver. Therefore, coffee consumption's negative correlation with the development of liver cancer is also attributed to polyphenols.
Although some chemicals in coffee are carcinogens in rodents at very high doses, research suggests that they are not dangerous at the levels consumed by humans. Instant coffee has a much greater amount of acrylamide than brewed coffee. Research suggests that drinking caffeinated coffee can cause a temporary stiffening of arterial walls. Coffee may aggravate pre-existing conditions such as migraines, arrhythmias, and cause sleep disturbances. It was once thought that coffee aggravates gastroesophageal reflux disease but recent research suggests no link
Some research suggests that a minority of moderate regular caffeine consumers experience some amount of clinical depression, anxiety, low vigor, or fatigue when discontinuing their caffeine use. However, the methodology of the these studies has been criticized. Withdrawal effects are more common and better documented in heavy caffeine users.
About 15% of the U.S. general population reports having stopped drinking coffee altogether, citing concerns about their health and the unpleasant side effects of caffeine.
A 2013 study by Liu et al. published in Mayo Clinic Proceedings established a correlation between coffee consumption >28 cups per week (>4 cups per day) and an increase in all-cause mortality in the total population of men and in men and women younger than 55 years. This correlation was not statistically significant for people aged 55 years and older. The authors noted that certain limitations exist in the study, such as a lack of data on different coffee preparations that can vary the overall composition of coffee's constituent compounds (e.g., cafestol, kahweol), which could impact CVD risk factors; a lack of data on marital status and total energy consumption; and possible residual confounding from health-risk factors such as smoking. One of the study's co-authors stated, "We're not saying that coffee is the cause of death; we just noticed coffee is associated with increased risk of death," which addresses the distinction between correlation and causation.
Caffeine and headaches
Caffeine alleviates headaches acutely and is used medically for this purpose, generally in combination with a painkiller such as ibuprofen. However, chronic caffeine use and withdrawal can cause headaches. Research has consistently linked caffeine withdrawal to headaches, even in those who drink coffee in moderation. Additionally, studies have suggested that those that drink four or more cups of coffee a day experience headaches more often than controls, even without discontinuing their coffee consumption.
The caffeine content of a cup of coffee varies depending mainly on the brewing method, and also on the variety of seed.
According to an article in the Journal of the American Dietetic Association, coffee has the following caffeine content, depending on how it is prepared:
|Serving size||Caffeine content|
|Brewed||7 oz, 207 ml||80–135 mg|
|Drip||7 oz, 207 ml||115–175 mg|
|Espresso||1.5–2 oz, 45–60 ml||100 mg|
While the percent of caffeine content in coffee seeds themselves diminishes with increased roast level, the opposite is true for coffee brewed from different grinds and brewing methods using the same proportion of coffee to water volume. The coffee sack (similar to the French press and other steeping methods) extracts more caffeine from dark roasted seeds; the percolator and espresso methods extract more caffeine from light roasted seeds.
|Light roast||Medium roast||Dark roast|
|Coffee sack – coarse grind||0.046||0.045||0.054|
|Percolator – coarse grind||0.068||0.065||0.060|
|Espresso – fine grind||0.069||0.062||0.061|
Social and culture
Coffee is often consumed alongside (or instead of) breakfast by many at home. It is often served at the end of a meal, normally with a dessert, and at times with an after-dinner mint especially when consumed at a restaurant or dinner party.
Aggressively promoted by the Pan-American Coffee Bureau, the "coffee break" was first promoted in 1952. Hitherto unknown in the workplace, its uptake was facilitated by the recent popularity of both instant coffee and vending machines, and has become an institution of the American workplace.
Most widely known as coffeehouses or cafés, establishments serving prepared coffee or other hot beverages have existed for over five hundred years.
Various legends involving the introduction of coffee to Istanbul at a "Kiva Han" in the late 15th century circulate in culinary tradition, but with no documentation.
Coffeehouses in Mecca soon became a concern as places for political gatherings to the imams who banned them, and the drink, for Muslims between 1512 and 1524. In 1530 the first coffee house was opened in Damascus. First coffee houses in Constantinople was opened in 1475 by traders arriving from Damascus and Aleppo. Soon after, coffee houses became part of the Ottoman Culture, spreading rapidly to all regions of the Ottoman Empire.
In the 17th century, coffee appeared for the first time in Europe outside the Ottoman Empire, and coffeehouses were established and quickly became popular. The first coffeehouses in Western Europe appeared in Venice, a result of the traffic between La Serenissima and the Ottomans; the very first one is recorded in 1645. The first coffeehouse in England was set up in Oxford in 1650 by a Jewish man named Jacob in the building now known as "The Grand Cafe". A plaque on the wall still commemorates this and the Cafe is now a trendy cocktail bar. By 1675, there were more than 3,000 coffeehouses in England.
After the second Turkish siege of Vienna in 1683, the Viennese discovered many bags of coffee in the abandoned Ottoman encampment. Using this captured stock, a Polish soldier named Kulczycki opened the first coffeehouse in Vienna.
In 1672 an Armenian named Pascal established a coffee stall in Paris that was ultimately unsuccessful and the city had to wait until 1689 for its first coffeehouse when Procopio Cutò opened the Café Procope. This coffeehouse still exists today and was a major meeting place of the French Enlightenment; Voltaire, Rousseau, and Denis Diderot frequented it, and it is arguably the birthplace of the Encyclopédie, the first modern encyclopedia. America had its first coffeehouse in Boston, in 1676. Coffee, tea and beer were often served together in establishments which functioned both as coffeehouses and taverns; one such was the Green Dragon in Boston, where John Adams, James Otis and Paul Revere planned rebellion.
The modern espresso machine was born in Milan in 1945 by Achille Gaggia, and from there spread across coffeehouses and restaurants across Italy and the rest of Europe and North America in the early 1950s. An Italian named Pino Riservato opened the first espresso bar, the Moka Bar, in Soho in 1952, and there were 400 such bars in London alone by 1956. Cappucino was particularly popular among English drinkers. Similarly in the United States, the espresso craze spread. North Beach in San Francisco saw the opening of the Caffe Trieste in 1957, which saw Beat Generation poets such as Allen Ginsberg and Bob Kaufman alongside bemused Italian immigrants. Similar such cafes existed in Greenwich Village and elsewhere.
The first Peet's Coffee & Tea store opened in 1966 in Berkeley, California by Dutch native Alfred Peet. He chose to focus on roasting batches with fresher, higher quality seeds than was the norm at the time. He was a trainer and supplier to the founders of Starbuck’s.
The international coffeehouse chain Starbucks began as a modest business roasting and selling quality coffee seeds in 1971, by three college students Jerry Baldwin, Gordon Bowker and Zev Siegl. The first store opened on March 30, 1971 at the Pike Place Market in Seattle, followed by a second and third over the next two years. Entrepreneur Howard Schultz joined the company in 1982 as Director of Retail Operations and Marketing, and pushed to sell premade espresso coffee. The others were reluctant, but Schultz opened Il Giornale in Seattle in April 1986. He bought the other owners out in March 1987 and pushed on with plans to expand—from 1987 to the end of 1991, the chain (rebranded from Il Giornale to Starbucks) expanded to over 100 outlets. The company has 16,600 stores in over 40 countries worldwide.
South Korea experienced almost 900 percent growth in the number of coffee shops in the country between 2006 and 2011. The capital city Seoul now has the highest concentration of coffee shops in the world, with more than 10,000 cafes and coffee houses.
Barista is a contemporary term for a person who makes coffee beverages, often a coffeehouse employee. Though the title is not regulated, highly skilled baristas may be trained in numerous methods of brewing, and may be knowledgeable about or involved in the production of coffee at every stage, from seed to cup.
Coffee was initially used for spiritual reasons. At least 1,100 years ago, traders brought coffee across the Red Sea into Arabia (modern-day Yemen), where Muslim dervishes began cultivating the shrub in their gardens. At first, the Arabians made wine from the pulp of the fermented coffee berries. This beverage was known as qishr (kisher in modern usage) and was used during religious ceremonies.
Coffee drinking was prohibited by jurists and scholars (ulema) meeting in Mecca in 1511 as haraam, but the subject of whether it was intoxicating was hotly debated over the next 30 years until the ban was finally overturned in the mid-16th century. Use in religious rites among the Sufi branch of Islam led to coffee's being put on trial in Mecca: it was accused of being a heretical substance, and its production and consumption were briefly repressed. It was later prohibited in Ottoman Turkey under an edict by the Sultan Murad IV.
Coffee, regarded as a Muslim drink, was prohibited by Ethiopian Orthodox Christians until as late as 1889; it is now considered a national drink of Ethiopia for people of all faiths. Its early association in Europe with rebellious political activities led to Charles II outlawing coffeehouses from January 1676 (although the uproar created forced the monarch to back down two days before the ban was due to come into force). Frederick the Great banned it in Prussia in 1777 for nationalistic and economic reasons; concerned about the price of import, he sought to force the public back to consuming beer. Lacking coffee-producing colonies, Prussia had to import all its coffee at a great cost.
A contemporary example of religious prohibition of coffee can be found in The Church of Jesus Christ of Latter-day Saints. The organization holds that it is both physically and spiritually unhealthy to consume coffee. This comes from the Mormon doctrine of health, given in 1833 by founder Joseph Smith in a revelation called the Word of Wisdom. It does not identify coffee by name, but includes the statement that "hot drinks are not for the belly," which has been interpreted to forbid both coffee and tea.
Quite a number of members of the Seventh-day Adventist Church also avoid caffeinated drinks. In its teachings, the Church encourages members to avoid tea and coffee and other stimulants. Abstinence from coffee, tobacco and alcohol by many Adventists has afforded a near unique opportunity for studies to be conducted within that population group on the health effects of coffee drinking, free from confounding factors. One study was able to show a weak but statistically significant association between coffee consumption and mortality from ischemic heart disease, other cardiovascular disease, all cardiovascular diseases combined, and all causes of death.
For a time, there had been controversy in the Jewish community over whether the coffee seed was a legume and therefore prohibited for Passover. Upon petition from coffeemaker Maxwell House, the coffee seed was classified in 1923 as a berry rather than a seed by orthodox Jewish rabbi Hersch Kohn, and therefore kosher for Passover.
The concept of fair trade labeling, which guarantees coffee growers a negotiated preharvest price, began with the Max Havelaar Foundation's labeling program in the Netherlands. In 2004, 24,222 metric tons (of 7,050,000 produced worldwide) were fair trade; in 2005, 33,991 metric tons out of 6,685,000 were fair trade, an increase from 0.34% to 0.51%. A number of fair trade impact studies have shown that fair trade coffee produces a mixed impact on the communities that grow it. Many studies are skeptical about Fair Trade, reporting that it often worsens the bargaining power of those who are not part of it. (For further information on this issue, see: http://en.wikipedia.org/wiki/Fair_trade_debate). Coffee was incorporated into the fair-trade movement in 1988, when the Max Havelaar mark was introduced in the Netherlands. The very first fair-trade coffee was an effort to import a Guatemalan coffee into Europe as "Indio Solidarity Coffee".
Since the founding of organisations such as the European Fair Trade Association (1987), the production and consumption of fair trade coffee has grown as some local and national coffee chains started to offer fair trade alternatives. For example, in April 2000, after a year-long campaign by the human rights organization Global Exchange, Starbucks decided to carry fair-trade coffee in its stores. Since September 2009 all Starbucks Espresso beverages in UK and Ireland are made with Fairtrade and Shared Planet certified coffee.
A 2005 study done in Belgium concluded that consumers' buying behavior is not consistent with their positive attitude toward ethical products. On average 46% of European consumers claimed to be willing to pay substantially more for ethical products, including fair-trade products such as coffee. The study found that the majority of respondents were unwilling to pay the actual price premium of 27% for fair trade coffee.
Folklore and culture
The Oromo people would customarily plant a coffee tree on the graves of powerful sorcerers. They believed that the first coffee bush sprang up from the tears that the god of heaven shed over the corpse of a dead sorcerer.
Market volatility, and thus increased returns, during 1830 encouraged Brazilian entrepreneurs to shift their attention from gold to coffee, a crop hitherto was reserved for local consumption. Concurrent with this shift was the commissioning of vital infrastructures, including approximately 7,000 km of railroads between 1860 and 1885. The creation of these railways enabled the importation of workers, in order to meet the enormous need for labor. This development primarily affected the State of Rio de Janeiro, as well as the Southern States of Brazil, most notably São Paulo, due to its favourable climate, soils, and terrain.
Coffee production attracted immigrants in search of better economic opportunities in the early 1900s. Mainly, these were Portuguese, Italian, Spanish, German, and Japanese nationals. For instance, São Paulo received approximately 733,000 immigrants in the decade preceding 1900, whilst only receiving approximately 201,000 immigrants in the six years to 1890. The production yield of coffee increases. In 1880, São Paulo produced 1.2 million bags (25% of total production), in 1888 2.6 million (40%), in 1902, 8 million bags (60%). Coffee is then 63% of the country's exports. The gains made by this trade allow sustained economic growth in the country.
The four years between planting a coffee and the first harvest extends seasonal variations in the price of coffee. The Brazilian Government is thus forced, to some extent, to keep strong price subsidies during production periods. This policy of price support is inflation negative effect of plantations in São Paulo, resulting in a huge blockbuster to early 1930.
Coffee competitions take place across the globe with people at the regional competing to achieve national titles and then compete on the international stage. World Coffee Events holds the largest of such events moving the location of the final competition each year. The competition includes the following events: Barista Championship, Brewers Cup, Latte Art and Cup Tasters. A World Brewer's Cup Championship takes place in Melbourne, Australia every year that houses contestants from around the world to crown the World's Coffee King.
While coffee is most well known as a beverage, it is also used as an ingredient in cooking. Recipes with coffee as a main or essential ingredient include North American pumpernickel, red-eye gravy, and tiramisu, among others. Coffee sauce is a culinary sauce that includes coffee in its preparation.
- Bean Belt
- Gustav III of Sweden's coffee experiment
- Health effects of caffeine
- List of countries by coffee consumption per capita
- Unofficial figure
- FAO estimate
- Aggregate (may include official, semiofficial, or estimates)
- Coffee and Health. Thecoffeefaq.com (2005-02-16). Retrieved on 2013-01-22.
- Villanueva, 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. doi:10.1002/ijc.21587. PMID 16284957.
- Kummer 2003, pp. 160–5
- Weinberg & Bealer 2001, pp. 3–4
- Pankhurst, Richard (1968). Economic History of Ethiopia. Addis Ababa: Haile Selassie I University. p. 198.
- Hopkins, Kate (March 24, 2006). "Food Stories: The Sultan's Coffee Prohibition". Accidental Hedonist. Retrieved January 3, 2010.
- "FAO Statistical Yearbook 2004 Vol. 1/1 Table C.10: Most important imports and exports of agricultural products (in value terms) (2004)" (PDF). FAO Statistics Division. 2006. Archived from the original on 2008-06-25. Retrieved September 13, 2007.
- "FAOSTAT Core Trade Data (commodities/years)". FAO Statistics Division. 2007. Archived from the original on October 14, 2007. Retrieved October 24, 2007. To retrieve export values: Select the "commodities/years" tab. Under "subject", select "Export value of primary commodity." Under "country," select "World." Under "commodity," hold down the shift key while selecting all commodities under the "single commodity" category. Select the desired year and click "show data." A list of all commodities and their export values will be displayed.
- Mussatto, Solange I.; Machado, Ercília M. S.; Martins, Silvia; Teixeira, José A. (2011). "Production, Composition, and Application of Coffee and Its Industrial Residues". Food and Bioprocess Technology 4 (5): 661–72. doi:10.1007/s11947-011-0565-z.
- "قها". الباحث العربي. Retrieved 25 September 2011. (Arabic)
- Simpson, JA; Weiner, ESC, eds. (1989). "Coffee". Oxford English Dictionary 3. Oxford: Clarendon Press. p. 438. ISBN 0-19-861186-2.
- Weinberg & Bealer 2001, p. 25
- Wild, Antony (2004-03-25). Coffee: A dark history. pp. 217–229. ISBN 9781841156491.
- Ukers, William (1935). All About Coffee. New York: Tea & Coffee Trade Journal Company. pp. 9–10.
- Souza 2008, p. 3
- "Budan Beans: The Story of Baba Budan".
- Meyers, Hannah (March 7, 2005). "Suave Molecules of Mocha—Coffee, Chemistry, and Civilization". New Partisan. New Partisan. Retrieved February 3, 2007.
- Ukers, William H (1922). "The Introduction of Coffee into Holland". All About Coffee. New York: Tea and Coffee Trade Journal. ISBN 0-8103-4092-5. Retrieved February 12, 2010.
- Dobelis, Inge N, ed. (1986). Magic and medicine of plants. Pleasantville, NY: Reader's Digest. pp. 370–71. ISBN 0-89577-221-3.
- Fischer, Dieter. "History of Indonesian coffee". Specialty Coffee Association of Indonesia. Retrieved February 12, 2010.
- Pendergrast 2001, p. 9
- Pendergrast 2001, p. 39
- (1) Adams, John (1774-07-06). "John Adams to Abigail Adams". The Adams Papers: Digital Editions: Adams Family Correspondence, Volume 1. Massachusetts Historical Society. Archived from the original on 2014-02-26. Retrieved 2014-02-25. "I believe I forgot to tell you one Anecdote: When I first came to this House it was late in the Afternoon, and I had ridden 35 miles at least. “Madam” said I to Mrs. Huston, “is it lawfull for a weary Traveller to refresh himself with a Dish of Tea provided it has been honestly smuggled, or paid no Duties?” “No sir, said she, we have renounced all Tea in this Place. I cant make Tea, but I'le make you Coffee.” Accordingly I have drank Coffee every Afternoon since, and have borne it very well. Tea must be universally renounced. I must be weaned, and the sooner, the better."
(2) Stone, William L. (1867). "Continuation of Mrs. General Riedesel's Adventures". Mrs. General Riedesel: Letters and Journals relating to the War of Independence and the Capture of the Troops at Saratoga (Translated from the Original German). Albany: Joel Munsell. p. 147. "She then became more gentle, and offered me bread and milk. I made tea for ourselves. The woman eyed us longingly, for the Americans love it very much; but they had resolved to drink it no longer, as the famous duty on the tea had occasioned the war." At Google Books. Note: Fredricka Charlotte Riedesel was the wife of General Friedrich Adolf Riedesel, commander of all German and Indian troops in General John Burgoyne's Saratoga campaign and American prisoner of war during the American Revolution.
(3) Heiss, Mary Lou; Heiss, Robert .J (2007). "A History of Tea: The Boston Tea Party". The Story of Tea: A Cultural History and Drinking Guide. pp. 21–24. At Google Books.
(4) Zuraw, Lydia (2013-04-24). "How Coffee Influenced The Course Of History". NPR. Archived from the original on 2014-02-26. Retrieved 2014-02-25.
(5) DeRupo, Joseph (2013-07-03). "American Revolution: Stars, Stripes—and Beans". NCA News. National Coffee Association. Archived from the original on 2014-02-26. Retrieved 2014-02-25.
(6) Luttinger, Nina; Dicum, Gregory (2006). The coffee book: anatomy of an industry from crop to the last drop. The New Press. p. 33. At Google Books.
- Pendergrast 2001, p. 13
- Fremont-Barnes, Gregory (2005). Nelson's Sailors. Osprey Publishing. p. 24. ISBN 978-1-84176-906-6.
- Pendergrast 2001, p. 14
- Mark Pendergrast (2010). Uncommon Grounds: The History of Coffee and How It Transformed Our World. Basic Books. p. 17. ISBN 978-0-465-02404-9.
- Pendergrast 2001, p. 16
- Pendergrast 2001, p. 19
- Pendergrast 2001, pp. 20–24
- Pendergrast 2001, pp. 33–34
- Pendergrast 2001, p. 35–36
- Cousin, Tracey L (June 1997). "Ethiopia Coffee and Trade". American University. Retrieved March 18, 2008.
- "Botanical Aspects". London: International Coffee Organization. Retrieved January 4, 2010.
- Charrier A, Berthaud J in Clifford & Wilson, p. 20
- van der Vossen, H. A. M. in Clifford & Wilson, p. 53
- Duke, James A (1983). "Coffea arabica L.". Purdue University. Retrieved January 4, 2010.
- "Feature Article: Peaberry Coffee". Acorns. 2004. Retrieved January 4, 2010.
- Hamon, S; Noirot, M; Anthony, F (1995). "Developing a coffee core collection using the principal components score strategy with quantitative data". Core Collections of Plant Genetic Resources (Wiley-Sayce Co). Retrieved January 4, 2010.
- T. Pradeepkumar; Kumar, Pradeep (1 January 2008). Management of Horticultural Crops: Vol.11 Horticulture Science Series: In 2 Parts. New India Publishing. pp. 601–. ISBN 978-81-89422-49-3.
- Wilson, K. C. in Clifford & Wilson, p. 158.
- Wilson, K. C. in Clifford & Wilson, pp. 161–62.
- Belachew, Mekete (2003). "Coffee". In Uhlig, Siegbert. Encyclopaedia Aethiopica 1. Weissbaden: Horrowitz. p. 763.
- Reynolds, Richard (February 1, 2006). "Robusta's Rehab". CoffeeGeek. Coffee Geek. Retrieved January 5, 2010.
- Benoit Daviron; Stefano Ponte (2005). The Coffee Paradox: Global Markets, Commodity Trade and the Elusive Promise of Development. Zed Books. p. 51. ISBN 978-1-84277-457-1.
- van der Vossen, H. A. M. in Clifford & Wilson, p. 55
- Waller JM, Bigger M, Hillocks RJ (2007). Coffee pests, diseases and their management. Wallingford, Oxfordshire: CABI. p. 171. ISBN 1-84593-129-7.
- Bardner, R. in Clifford & Wilson, pp. 208–09.
- Bardner, R. in Clifford & Wilson, p. 210.
- Bardner, R. in Clifford & Wilson, p. 211.
- Bardner, R. in Clifford & Wilson, p. 213.
- Bardner, R. in Clifford & Wilson, p. 214.
- "Insect-eating birds reduce worst coffee plantation pest by 50 percent". birdsnews.com. Sep 5, 2013. Retrieved Sep 20, 2013.
- "Food and Agricultural Organization of United Nations: Economic and Social Department: The Statistical Division". Faostat.fao.org. February 23, 2012. Retrieved June 7, 2012.
- "Total production of exporting countries". International Coffee Organization. April 26, 2012. Retrieved Dec 24, 2012.
- "Coffee: World Markets and Trade" (PDF). Foreign Agricultural Service Office of Global Analysis. United States Department of Agriculture. December 2009. Retrieved March 26, 2010.
- Davids, Kenneth (2001). Coffee: A Guide to Buying Brewing and Enjoying (5th ed.). New York: St. Martin's Griffin. ISBN 0-312-24665-X.
- Castle, Timothy James (1991). The Perfect Cup: A Coffee Lover's Guide to Buying, Brewing, and Tasting. Reading, Mass.: Aris Books. p. 158. ISBN 0-201-57048-3.
- Janzen, Daniel H, ed. (1983). Costa Rican natural history. Chicago: University of Chicago Press. ISBN 0-226-39334-8.
- Wilson, K. C. in Clifford & Wilson, p. 166.
- Salvesen, David (1996). "The Grind Over Sun Coffee". Zoogoer (Smithsonian National Zoological Park) 25 (4). Retrieved January 5, 2010.
- Wilson, K. C. in Clifford & Wilson, p. 165.
- "Measuring Consumer Interest in Mexican Shade-grown Coffee". Montréal: Commission for Environmental Cooperation. October 1999. p. 5. Retrieved 18 January 2010.
- "Shade-Grown Coffee Plantations". Smithsonian Zoolongical Park website – Migratory Bird Center. Smithsonian Institution. Retrieved January 8, 2010.
- "Rain Forest- Saving Arbor Day Coffee". Arbor Day Foundation. Retrieved January 8, 2010.
- Wong, Kate (September 27, 2000). "Is Shade-Grown Coffee for the Birds?". Scientific American. Retrieved 18 January 2010.
- Rickert, Eve (December 15, 2005). Environmental effects of the coffee crisis: a case study of land use and avian communities in Agua Buena, Costa Rica. MES thesis. The Evergreen State College. Retrieved January 11, 2010.
- Pearce, Fred (February 25, 2006). "Earth: The parched planet". New Scientist. Retrieved January 5, 2010.
- Perlman, Howard (2010). "Water Science for Schools: Water used to grow common foods". U.S. Geological Survey. Retrieved 16 July 2010.
- Martin, Deborah L; Gershuny, eds. (1992). "Coffee wastes". The Rodale book of composting. Emmaus, Pa: Rodale Press. p. 86. ISBN 978-0-87857-991-4. Retrieved January 5, 2010.
- "Grounds for Your Garden". Starbucks.com. Retrieved 2011-10-26.
- "About Us | Coffee Grounds to Ground". Groundtoground.org. Retrieved 2011-10-26.
- Goldenberg, Suzanne. "Starbucks concerned world coffee supply is threatened by climate change." The Guardian, 13 October 2011.
- Vincent, J.-C. in Clarke & Macrae, p. 1.
- Kummer 2003, p. 38
- Marcone, Massimo F (2004). "Composition and properties of Indonesian palm civet coffee (Kopi Luwak) and Ethiopian civet coffee". Food Research International 37 (9): 901–912.
- "Most Expensive Coffee". Forbes.com. 2006-07-19. Retrieved 2011-10-26.
- Kummer 2003, p. 37
- Ball, Trent; Guenther, Sara; Labrousse, Ken; Wilson, Nikki. "Coffee Roasting". Washington State University. Archived from the original on July 1, 2007. Retrieved July 18, 2007.
- Kummer 2003, p. 261
- Cipolla, Mauro. "Educational Primer: Degrees of Roast". Bellissimo Info Group. Retrieved January 11, 2010.
- "Which Has More Caffeine: Light or Dark Roast Coffee?". Scribblers Coffee. Retrieved 2 April 2013.
- "Coffee Roasting Operations". Permit Handbook. Bay Area Air Quality Management District. May 15, 1998. Retrieved January 11, 2010.
- "Swiss Water Process". Swisswater.com. Retrieved 2011-10-26.
- Consumer Reports (May 2013). "Top Coffee Ratings - Coffee Buying Guide". consumerreports.org. Storing coffee. Retrieved 27 February 2014.
- Brown, Alton. "True Brew". Food Network. Retrieved January 11, 2010.
- New Process Keep Coffee Fresh In High Vacuum Cans. Popular Science. October 1931. Retrieved 2011-10-26.
- Borchgrevink, Carl P; Susskind, Alex M; Tarras, John M (1999). "Consumer preferred hot beverage temperatures". Food Quality and Preference 10 (2): 117–21. doi:10.1016/S0950-3293(98)00053-6.
- Rothstein, Scott. "Brewing Techniques". The Coffee FAQ. Retrieved January 11, 2010.
- Ukers, William Harrison (1922). All about Coffee (2nd ed.). Gale Research. p. 725. ISBN 978-0-8103-4092-3. Retrieved January 12, 2010.
- Levy, Joel (November 2002). Really Useful: The Origins of Everyday Things. Firefly Books. p. 1948. ISBN 978-1-55297-622-7. Retrieved January 11, 2010.
- Davids, Kenneth (1991). Coffee: A Guide to Buying, Brewing, and Enjoying. 01 Productions. p. 128. ISBN 978-1-56426-500-5. Retrieved January 11, 2010.
- Prince, Mark (11 Nov 3003). "How To Use A Press Pot". coffeegeek.com. Retrieved 9 Dec 2013.
- Salvaggio, Antonino; et al., M; Miano, L; Quaglia, G; Marzorati, D (1991). "Coffee and Cholesterol, an Italian Study". Am. J. Epidemiol. 134 (2): 149–156. PMID 1862798.
- Bonné, Jon (August 20, 2004). "My coffee is cold: A brewing system without heat proves it's a contender when it comes to taste". msnbc.com. Retrieved January 11, 2010.
- Castle, Timothy; Joan Nielsen (1999). The Great Coffee Book. Ten Speed Press. p. 94. ISBN 978-1-58008-122-1. Retrieved January 11, 2010.
- Fried, Eunice (November 1993). "The lowdown on caffe latte". Black Enterprise. Retrieved January 11, 2010.
- Miller, Emily Wise (May 2003). The Food Lover's Guide to Florence: With Culinary Excursions in Tuscany. Ten Speed Press. p. 12. ISBN 978-1-58008-435-2. Retrieved January 11, 2010.
- Hobhouse, Henry (December 13, 2005). Seeds of Wealth: Five Plants That Made Men Rich. Shoemaker & Hoard. p. 294. ISBN 978-1-59376-089-2. Retrieved January 11, 2010.
- Pendergrast 2001, p. 119
- Instant Coffee – How it's made. Coffeetea.about.com (2009-10-06). Retrieved on 2012-05-25.
- Pendergrast 2001, p. 195
- Pendergrast 2001, p. 196
- Pendergrast 2001, p. 197
- "Report: Coke, Pepsi faceoff brewing". CNN Money (Cable news network). December 6, 2005. Retrieved January 11, 2010.
- "Regarding liquid coffee concentrate". Commodities Report (The Wall Street Journal). March 21, 2005. p. C4.
- FAO (2003). "Coffee". Medium-term prospects for agricultural commodities. Projections to the year 2010. Food and Agriculture Organization of the United Nations. Retrieved January 11, 2010. "Global output is expected to reach 7.0 million metric tons (117 million bags) by 2010 compared with 6.7 million metric tons (111 million bags) in 1998–2000"
- Scofield, Alex. "Vietnam: Silent Global Coffee Power". INeedCoffee. Retrieved January 13, 2010.
- Allison, Melissa (2013-04-12). "Starbucks lowers prices on bagged coffee at grocers | Business & Technology". The Seattle Times. Retrieved 2013-05-03.
- Topper, R (15 October 2012). "Elephant Dung Coffee: World's Most Expensive Brew Is Made With Pooped-Out Beans". The Huffington Post. Retrieved 10 December 2012.
- NYMEX Coffee Futures Contract Overview via Wikinvest
- Ellis, Blake (September 10, 2010). "Coffee prices on the rise". CNN Money. Retrieved April 3, 2012.
- Galatola, Thomas (February 14, 2012). "Coffee Futures Fall to Lowest in 14 Months: Commodities at Close". Bloomberg News. Retrieved April 3, 2012.
- Pendergrast, Mark (1999). Uncommon Grounds: The History of Coffee and How It Transformed Our World. New York: Basic Books. ISBN 978-0-465-03631-8.
- Pendergrast, Mark (April 2009). "Coffee: Second to Oil?". Tea & Coffee Trade Journal: 38–41. Archived from the original on
|archivedate=(help). Retrieved January 13, 2010.
- Herraiz, Tomas; Chaparro, Carolina (2006). "Human monoamine oxidase enzyme inhibition by coffee and β-carbolines norharman and harman isolated from coffee". Life Sciences 78 (8): 795–802. doi:10.1016/j.lfs.2005.05.074. PMID 16139309.
- Zivković, R (2000). "Coffee and health in the elderly". Acta Medica Croatica 54 (1): 33–6. PMID 10914439.
- Freedman, N. D.; Park, Y.; Abnet, C. C.; Hollenbeck, A. R.; Sinha, R. (2012). "Association of Coffee Drinking with Total and Cause-Specific Mortality". New England Journal of Medicine 366 (20): 1891–1904. doi:10.1056/NEJMoa1112010. PMC 3439152. PMID 22591295.
- Boyles, Salynn (October 13, 2008). "Caffeine, Breast Cancer Link Minimal". WebMD. Retrieved January 26, 2010.
- "Coffee and cancer – a clearer picture". Cancer Research UK. 21 May 2012. Retrieved August 2013.
- Eskelinen, M.; Ngandu, T.; Tuomilehto, J.; Soininen, H.; Kivipelto, M. (2009). "Midlife coffee and tea drinking and the risk of late-life dementia: a population-based CAIDE study". Journal of Alzheimer's disease : JAD 16 (1): 85–91. doi:10.3233/JAD-2009-0920. PMID 19158424. Related article in ScienceDaily: 
- Catalano D, Martines GF, Tonzuso A, Pirri C, Trovato FM, Trovato GM. (2010). "Protective role of coffee in non-alcoholic fatty liver disease (NAFLD)". Dig Dis Sci 55 (11): 3200–3206. doi:10.1007/s10620-010-1143-3. PMID 20165979.
- Klatsky, Arthur L; Morton, Cynthia; Udaltsova, Natalia; Friedman, Gary D (2006). "Coffee, cirrhosis, and transaminase enzymes". Archives of Internal Medicine 166 (11): 1190–5. doi:10.1001/archinte.166.11.1190. PMID 16772246.
- Pereira, Mark A; Parker, Emily D; Folsom, Aaron R (2006). "Coffee consumption and risk of type 2 diabetes mellitus: an 11-year prospective study of 28 812 postmenopausal women". Archives of Internal Medicine 166 (12): 1311–6. doi:10.1001/archinte.166.12.1311. PMID 16801515.
- Cheng, Biao; Xinran Liu, Hao Gong, Lianqi Huang, Hong Chen, Xin Zhang, Chuanzhou Li, Muyang Yang, Bingjun Ma, Lihua Jiao, Ling Zheng, Kun Huang (2011). "Coffee Components Inhibit Amyloid Formation of Human Islet Amyloid Polypeptide in Vitro: Possible Link between Coffee Consumption and Diabetes Mellitus". Journal of Agricultural and Food Chemistry 59 (24): 13147–13155. doi:10.1021/jf201702h. PMID 22059381.
- Bakalar, Nicholas (August 15, 2006). "Coffee as a Health Drink? Studies Find Some Benefits". The New York Times. Retrieved January 26, 2010.
- Chu, Y. F.; Brown, P. H.; Lyle, B. J.; Chen, Y.; Black, R. M.; Williams, C. E.; Lin, Y. C.; Hsu, C. W.; Cheng, I. H. (2009). "Roasted Coffees High in Lipophilic Antioxidants and Chlorogenic Acid Lactones Are More Neuroprotective than Green Coffees". Journal of Agricultural and Food Chemistry 57 (20): 9801–9808. doi:10.1021/jf902095z. PMID 19772322.
- Wu, Jiang-nan; Ho, Suzanne C; Zhou, Chun; Ling, Wen-hua; Chen, Wei-qing; Wang, Cui-ling; Chen, Yu-ming (2009). "Coffee consumption and risk of coronary heart diseases: A meta-analysis of 21 prospective cohort studies". International Journal of Cardiology 137 (3): 216–25. doi:10.1016/j.ijcard.2008.06.051. PMID 18707777.
- Mostofsky, E.; Rice, M. S.; Levitan, E. B.; Mittleman, M. A. (2012). "Habitual Coffee Consumption and Risk of Heart Failure: A Dose-Response Meta-Analysis". Circulation: Heart Failure 5 (4): 401. doi:10.1161/CIRCHEARTFAILURE.112.967299.
- Siasos, Gerasimos; Tousoulis, Dimitris; Stefanadis, Christodoulos (2013). "Effects of Habitual Coffee Consumption on Vascular Function". Journal of the American College of Cardiology. doi:10.1016/j.jacc.2013.08.1642.
- Siasos, G.; Oikonomou, E.; Chrysohoou, C.; Tousoulis, D.; Panagiotakos, D.; Zaromitidou, M.; Zisimos, K.; Kokkou, E.; Marinos, G.; Papavassiliou, A. G.; Pitsavos, C.; Stefanadis, C. (2013). "Consumption of a boiled Greek type of coffee is associated with improved endothelial function: The Ikaria Study". Vascular Medicine 18 (2): 55–62. doi:10.1177/1358863X13480258. PMID 23509088.
- Lucas M et al. (September 2011). "Coffee, caffeine, and risk of depression among women". Archives of internal medicine 171 (17): 1571–1578. doi:10.1001/archinternmed.2011.393. PMID 21949167.
- de Paulis, Tomas; Martin, Peter R (April 27, 2004). "Cerebral effects of noncaffeine constituents in roasted coffee". In Nehlig, Astrid. Coffee, Tea, Chocolate, and the Brain. London: Taylor & Francis. pp. 187–196. ISBN 0-415-30691-4.
- Siasos, G.; Oikonomou, E.; Chrysohoou, C.; Tousoulis, D.; Panagiotakos, D.; Zaromitidou, M.; Zisimos, K.; Kokkou, E.; Marinos, G.; Papavassiliou, A. G.; Pitsavos, C.; Stefanadis, C. (2013). "Consumption of a boiled Greek type of coffee is associated with improved endothelial function: The Ikaria Study". Vascular Medicine 18 (2): 55–62. doi:10.1177/1358863X13480258. PMID 23509088.
- Atanasov, AG; Dzyakanchuk, AA; Schweizer, RA; Nashev, LG; Maurer, EM; Odermatt, A (2006). "Coffee inhibits the reactivation of glucocorticoids by 11beta-hydroxysteroid dehydrogenase type 1: A glucocorticoid connection in the anti-diabetic action of coffee?". FEBS Letters 580 (17): 4081–5. doi:10.1016/j.febslet.2006.06.046. PMID 16814782.
- Cornelis, MC; El-Sohemy, A (2007). "Coffee, caffeine, and coronary heart disease". Current Opinion in Clinical Nutrition and Metabolic Care 10 (6): 745–51. doi:10.1097/MCO.0b013e3282f05d81. PMID 18089957.
- Baukje de Roos, B; Sawyer, JK; Katan, MB; Rudel, LL (August 1999). "Symposium on 'functionality of nutrient and food safety': validity of animal models for cholesterol-raising effects of coffee diterpenes in human subjects". Proceedings of the Nutrition Society 58 (3): 551–7. doi:10.1017/S0029665199000725. PMID 10604186.
- Dewey, Kathryn G; Romero-Abal, Maria Eugenia; Quan De Serrano, Julieta; Bulux, Jesus; Peerson, Janet M; Eagle, Patrice; Solomons, Noel W (1997). "Effects of discontinuing coffee intake on iron status of iron-deficient Guatemalan toddlers: a randomized intervention study". American Journal of Clinical Nutrition 66 (1): 168–76. PMID 9209186.
- Muñoz, Leda M; Lönnerdal, Bo; Keen, Carl L; Dewey, Kathryn G (1988). "Coffee consumption as a factor in iron deficiency anemia among pregnant women and their infants in Costa Rica". American Journal of Clinical Nutrition 48 (3): 645–51. PMID 3414579.
- Nkondjock, André (May 18, 2009). "Coffee consumption and the risk of cancer: An overview". Cancer Letters 277 (2): 121–5. doi:10.1016/j.canlet.2008.08.022. PMID 18834663.
- Ames, Bruce N; Gold, Lois Swirsky (1998). "The causes and prevention of cancer: the role of environment". Biotherapy 11 (2–3): 205–20. doi:10.1023/A:1007971204469. PMID 9677052.
- "Survey Data on Acrylamide in Food: Individual Food Products". Food and Drug Administration. December 2002. Updated March 2003, March 2004, June 2005 and July 2006. Retrieved 15 August 2013.
- Mahmud, Azra; Feely, John (2001). "Acute effect of caffeine on arterial stiffness and aortic pressure waveform". Hypertension (American Heart Association) 38 (2): 227–31. doi:10.1161/01.HYP.38.2.227. PMID 11509481.
- Palmer, Sharon (May 2009). "Coffee Buzz – Trends and Possible Perks of America's Beloved Beverage". Today's Dietitian 11 (5): 26. Retrieved February 2, 2010.
- Kim, J.; Oh, S.-W.; Myung, S.-K.; Kwon, H.; Lee, C.; Yun, J. M.; Lee, H. K. (2013). "Association between coffee intake and gastroesophageal reflux disease: A meta-analysis". Diseases of the Esophagus. doi:10.1111/dote.12099. PMID 23795898.
- Smith, A (2002). "Effects of caffeine on human behavior". Food and Chemical Toxicology 40 (9): 1243–55 (1245, 1249). doi:10.1016/S0278-6915(02)00096-0. PMID 12204388. Retrieved February 12, 2010.
- Broderick, P; Benjamin, AB (2004). "Caffeine and psychiatric symptoms: A review". The Journal of the Oklahoma State Medical Association 97 (12): 538–42. PMID 15732884.
- Silverman, K; Evans, SM; Strain, EC; Griffiths, RR (October 15, 1992). "Withdrawal syndrome after the double-blind cessation of caffeine consumption". New England Journal of Medicine (Massachusetts Medical Society) 327 (16): 1109–1114. doi:10.1056/NEJM199210153271601. PMID 1528206. Retrieved February 12, 2010.
- Butt, M.S.; Sultan, M.T. (2011). "Coffee and its consumption: benefits and risks". Critical Reviews in Food Science and Nutrition 51 (4): 363–73. doi:10.1080/10408390903586412. PMID 21432699.
- "Use and Common Sources of Caffeine". Information about Caffeine Dependence. Johns Hopkins University School of Medicine. 2003. Retrieved February 12, 2010.
- Liu, Junxiu; Sui, Xuemei (15 August 2013). "Association of Coffee Consumption With All-Cause and Cardiovascular Disease Mortality". Mayo Clinic Proceedings. Mayo Clinic Proceedings. doi:10.1016/j.mayocp.2013.06.020. Retrieved 16 August 2013.
- Miller, Tracy (15 August 2013). "More than 4 cups of coffee a day linked to higher mortality rate, particularly in under-55s: study". NY Daily News. Retrieved 16 August 2013.
- "Caffeine Withdrawal". Information about Caffeine Dependence. Johns Hopkins University School of Medicine. 2003. Retrieved February 12, 2010.
- "Bad News For Coffee Drinkers Who Get Headaches". August 14, 2009. Retrieved 10-07-2010. Rosenthal, Elisabeth (October 15, 1992). "Headache? You Skipped Your Coffee". The New York Times. Retrieved 10-07-2010. "How A Cup Of Coffee Could Ease Your Headache". October 14, 2000. Retrieved 10-07-2010.
- See for example the following websites: "Coffee and Caffeine's Frequently Asked Questions". faqs.org. Retrieved 8 December 2010., "How Much Caffeine In A Cup Of Coffee, Tea, Cola or Chocolate Bar?". talkaboutcoffee.com. Retrieved 8 December 2010., "How much caffeine is there in (drink/food/pill?)". 2006-01-15.
- Bunker, ML; McWilliams, M (1979). "Caffeine content of common beverages". Journal of the American Dietetic Association 74 (1): 28–32. PMID 762339.
- Verlengia F, Rigitano A, Nery JP, Tosello A. Variations of the caffeine content in coffee beverages. ASIC, 2nd Int Sci Colloq Green and Roasted Coffee Chem. 1965, 106–114.
- Huneidi, Sahar (May 9, 2004). "Your Fortune In A Cup:". PS-Magazine.com. Retrieved February 13, 2010.
- Standage, Tom (June 14, 2007). A History of the World in Six Glasses. Atlantic Books. ISBN 978-1-84354-595-8. Retrieved February 13, 2010.
- La Dolce Vita. 1999. Coffee. London, UK: New Holland Books
- Cowan, Brian (October 2006). "Rosee, Pasqua (fl. 1651–1656)". Oxford Dictionary of National Biography. doi:10.1093/ref:odnb/92862. Subscription required.
- "History of Coffee". Nestlé Professional. Nestlé. 2010. Retrieved February 13, 2010.
- Millar, Simon. Vienna 1683, p. 93. Osprey Publishing, 2008. ISBN 1-84603-231-8.
- Weinberg & Bealer 2001, pp. 71–72
- Danko, C (2009). "America's First Coffeehouse". Massachusetts Travel Journal. Masstraveljournal.com. Retrieved February 13, 2010.
- Pendergrast 2001, p. 218
- Pendergrast 2001, p. 219
- Marshall, Carolyn (September 3, 2007). "Alfred H. Peet, 87, Dies; Leader of a Coffee Revolution". New York Times.
- Pendergrast 2001, pp. 252–53
- Pendergrast 2001, p. 301
- Pendergrast 2001, p. 302
- "Starbucks Corporation". Company profile from Hoover's. Hoover's. 2010. Retrieved February 13, 2010.
- "Coffee Expo Seoul 2013 to Provide Hub for Korea's Booming Coffee Market". Asia Today. 5 February 2013. Retrieved 24 June 2013.
- Pendergrast 2001, p. 5
- Brown, Daniel W (2004). A new introduction to Islam. Chichester, West Sussex: Wiley-Blackwell. pp. 149–51. ISBN 1-4051-5807-7.
- Pendergrast 2001, p. 11
- Bersten 1999, p. 53
- "Coffee facts, coffee trivia & coffee information!". Coffee Facts. Retrieved February 13, 2010.
- "Who Are the Mormons?". Beliefnet. Retrieved February 13, 2010.
- "Coffee consumption and mortality in Seventh-Day Adventists". Nutrition Research Newsletter (Frost & Sullivan). September 1992. Retrieved February 13, 2010.
- "A few new Passover haggadahs, and a facelift for an old favorite". JTA.
- "Total Production of Exporting Countries, 2003 to 2008". International Coffee Organization. Retrieved January 13, 2010.
- "Coffee". Fairtrade Labelling Organizations International. Retrieved January 13, 2010.
- Rice, Robert A (March 2001). "Noble Goals and Challenging Terrain: Organic and Fair Trade Coffee Movements" (PDF). Journal of Agricultural and Environmental Ethics (Springer Netherlands) 14 (1): 39–66. doi:10.1023/A:1011367008474. Retrieved January 13, 2010.
- "European Fair Trade Association". EFTA. 2009. Retrieved January 18, 2010.
- Balch-Gonzalez, Margaret (2003). "Good Coffee, Better World, The Ethics and Economics of Fair Trade Coffee". Retrieved January 13, 2010.
- De Pelsmacker, Patrick; Driesen, Liesbeth; Rayp, Glenn (2005). "Do Consumers Care about Ethics? Willingness to Pay for Fair-Trade Coffee". Journal of Consumer Affairs 39 (2): 363–385. doi:10.1111/j.1745-6606.2005.00019.x.
- "Starbucks Serves up its First Fairtrade Lattes and Cappuccinos Across the UK and Ireland". London: Fairtrade Foundation. September 2, 2009. Retrieved January 22, 2010.
- Allen 1999, p. 27
- Pendergrast 2001, p. 10
- "Breakfast buffet: National coffee day – Eatocracy – CNN.com Blogs". Eatocracy.cnn.com. September 29, 2011. Retrieved 2011-10-26.
- "Ten things you didn’t know about coffee". Global Saskatoon. September 29, 2011. Retrieved 4 November 2013.
- Mattoon, Jr., Robert H. (2 May 1977). Railroads, Coffee, and the Growth of Big Business in São Paulo, Brazil 57 (2). pp. 273–295. JSTOR 2513775.
- "Economía del café en Brasil de 1840 a 1930" (in inglés).
- Smith, Teresa (2013-04-22). "Canadian coffee king crowned in Ottawa". Ottawacitizen.com. Retrieved 2013-05-03.
- "World Brewers Cup". World Brewers Cup. Retrieved 2013-05-03.
- "World Coffee Events". Retrieved 26 April 2013.
- Allen, Stewart Lee (1999). The Devil's Cup: Coffee, the Driving Force in History. Soho: Random House. ISBN 1-56947-174-6.
- Bersten, Ian (1999). Coffee, Sex & Health: A History of Anti-coffee Crusaders and Sexual Hysteria. Sydney: Helian Books. ISBN 0-9577581-0-3.
- Clarke, Ronald James; Macrae, R, eds. (1987). Coffee. 2: Technology. Barking, Essex: Elsevier Applied Science. ISBN 1-85166-034-8.
- various (1985). "Botanical Classification of Coffee". In Clifford MH, Wilson KC (eds.). Coffee: Botany, Biochemistry and Production of Beans and Beverage. Westport, Connecticut: AVI Publishing. ISBN 0-7099-0787-7.
- Ganchy, Sally (2009). Islam and Science, Medicine, and Technology. The Rosen Publishing Group. ISBN 1-4358-5066-1.
- Hünersdorff, Richard von & Hasenkamp, Holger G. (2002) Coffee: a bibliography : a guide to the literature on coffee London: Hünersdorff
- Jacob, Heinrich Eduard (1998). Coffee: The Epic of a Commodity. Short Hills, N.J.: Burford Books. ISBN 978-1-58080-070-9.
- Kummer, Corby (August 19, 2003). The Joy of Coffee: The Essential guide to Buying, Brewing, and Enjoying. Boston: Houghton Mifflin. ISBN 0-618-30240-9.
- Luttinger, Nina and Dicum, Gregory. The Coffee Book: Anatomy of an Industry from Crop to the Last Drop(Bazaar Book, 2006)
- Metcalf, Allan A (1999). The World in So Many Words: A Country-by-country Tour of Words that have Shaped our Language. Houghton Mifflin. ISBN 0-395-95920-9.
- Pendergrast, Mark (2001) . Uncommon Grounds: The History of Coffee and How It Transformed Our World. London: Texere. ISBN 1-58799-088-1.
- Rao, Scott. The Professional Barista's Handbook.
- Siasos G, Oikonomou E, Chrysohoou C, Tousoulis D, Panagiotakos D, Zaromitidou M, Zisimos K, Kokkou E, Marinos G, Papavassiliou AG, Pitsavos C, Stefanadis C. Consumption of a boiled Greek type of coffee is associated with improved endothelial function: the Ikaria study. Vasc Med. 2013 Apr;18(2):55-62. doi: 10.1177/1358863X13480258. Epub 2013 Mar 18. PubMed PMID 23509088.
- Siasos G, Tousoulis D, Stefanadis C. Effects of Habitual Coffee Consumption on Vascular Function. J Am Coll Cardiol. 2013 Oct 17. doi:pii: S0735-1097(13)05682-9. 10.1016/j.jacc.2013.08.1642. [Epub ahead of print] PubMed PMID 24184234.
- Souza, Ricardo M (2008). Plant-Parasitic Nematodes of Coffee. シュプリンガー・ジャパン株式会社. ISBN 978-1-4020-8719-6.
- Weinberg, Bennett Alan; Bealer, Bonnie K (2001). The World of Caffeine: The Science and Culture of the World's Most Popular Drug. New York: Routledge. ISBN 0-415-92722-6.
- Weissman, Michaele. God in a Cup: The Obsessive Quest for the Perfect Coffee
|Wikimedia Commons has media related to Coffee.|
|Look up coffee in Wiktionary, the free dictionary.|
- Bhanoo, Sindya N. (2013-03-25). "The Secret May Be in the Coffee". New York Times. Retrieved 2013-12-04.
- Osterweil, Neil. "Coffee and Your Health". WebMD. Retrieved 24 November 2010.
- Coffee and caffeine health information— A collection of peer-reviewed and journal-published studies on coffee health benefits is evaluated, cited, and summarized. (Note, while the COSIC itself receives funding from some coffee makers as some have pointed out, the studies it examines are themselves from and done by independent scientists and scientific groups. It itself does not participate in or fund the studies.)
- Benjamin Joffe-Walt and Oliver Burkeman, The Guardian, September 16, 2005, "Coffee trail"—from the Ethiopian village of Choche to a London coffee shop.
- 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 dos and don'ts of making "the perfect cup of coffee" and an overview of different ways to enjoy coffee throughout the world.
- An Illustrated Coffee Guide—Side-by-side diagrams of a few common espresso drinks.
- F. Engelmann, M.E. Dulloo, C. Astorga, S. Dussert and F. Anthony (2007). Complementary strategies for ex situ conservation of coffee (Coffea arabica L.) genetic resources. A case study in CATIE, Costa Rica. Topical reviews in Agricultural Biodiversity. Bioversity International, Rome, Italy.
- Coffee Taster, the free newsletter of the International Institute of Coffee Tasters, featuring articles on the quality of espresso, chemical and sensory analysis, market trends.
- Morris, Jonathan (2007). "The Cappuccino Conquests. The Transnational History of Italian Coffee". summary.
- Booknotes interview with Mark Pendergrast on Uncommon Grounds: The History of Coffee and How It Transformed Our World, August 29, 1999.
- Articles on world coffee trade at the Agritrade web site.