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 bean both physically and chemically. The bean decreases in weight as moisture is lost and increases in volume, causing it to become less dense.
The density of the bean also influences the strength of the coffee and requirements for packaging.
The actual roasting begins when the temperature inside the bean reaches approximately 200 °C (392 °F), though different varieties of beans differ in moisture and density and therefore roast at different rates. During roasting, caramelization occurs as intense heat breaks down starches in the bean, changing them to simple sugars that begin to brown, changing the color of the bean.
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 is caffeol, created at about 200 °C (392 °F), which is largely responsible for coffee's aroma and flavor.
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 the flesh of the berry is removed, usually by machine, and the seeds—usually called beans—are fermented to remove the slimy layer of mucilage still present on the bean. When the fermentation is finished, the beans 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 beans 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 beans, 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 beans 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 beans with much less bitterness, widely noted as the most expensive coffee in the world with prices reaching $160 per pound.
Coffee is a brewed beverages with a dark, acidic flavor prepared from the roasted seeds of the coffee plant, colloquially called coffee beans. The beans are found in coffee cherries, which grow on trees cultivated in over 70 countries
Coffee cherries are commonly found in Latin America, Southeast Asia, South Asia and Africa. Green (unroasted) coffee is one of the most traded agricultural commodities in the world. Coffee can have a stimulating effect on humans due to its caffeine content. It is one of the most-consumed beverages in the world
Coffee has played a crucial role in many societies. The energizing effect of the coffee bean plant is thought to have been discovered in the northeast region of Ethiopia, and the cultivation of coffee first expanded in the Arab world.
The earliest credible evidence of coffee drinking appears in the middle of the 15th century, in the Sufi shrines of Yemen in southern Arabia. From the Muslim world, coffee spread to India, Italy, then to the rest of Europe, to Indonesia, and to the Americas. In East Africa and Yemen, it was used in religious ceremonies. As a result, the Ethiopian Church banned its secular consumption, a ban in effect until the reign of Emperor Menelik II of Ethiopia. It was banned in Ottoman Turkey during the 17th century for political reasons, and was associated with rebellious political activities in Europe.
Coffee berries, which contain the coffee seeds or "beans", are produced by several species of small evergreen bush of the genus Coffea. The two most commonly grown are the highly regarded Coffea arabica, and the "robusta" form of the hardier Coffea canephora. The latter is resistant to the devastating coffee leaf rust (Hemileia vastatrix). Once ripe, coffee berries are picked, processed, and dried. The seeds are then roasted to varying degrees, depending on the desired flavor. They are then ground and brewed to create coffee. Coffee can be prepared and presented in a variety of ways.
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. Some controversy is associated with coffee cultivation and its impact on the environment. Many studies have examined the relationship between coffee consumption and certain health conditions; whether the overall effects of coffee are ultimately positive or negative has been widely disputed. The method of brewing coffee has been found to be important to its health effects.
