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Coffee Guide
Coffee trees are indigenous to Africa, and can still be found growing wild in the hills of Ethiopia. Today coffee is cultivated in some eighty countries in South and Central America, the Caribbean, Africa and Asia, generally in areas lying between the Tropics of Cancer and Capricorn. The two biggest producers by far are Brazil and Colombia, followed by Indonesia, Vietnam and Mexico.
The coffee tree is a tropical evergreen shrub (genus Coffea), and two beans are generally contained in each fruit, which when ripe resembles a red cherry. The two most commercially important species grown are varieties of Coffea canephora (robustas) and Coffea arabica (arabicas). The latter grows at higher altitudes, requires less rain, and its beans have a lower caffeine content than that of robustas.
The trees do not start fruiting until they are between three and five years old, when each tree will yield between two and four kg of fruit. Most coffee is still harvested by hand, although some larger farms now employ mechanical harvesters.
After harvesting the next stage is to remove the outer layers of the bean and create a stable, dry, green coffee bean. Two methods may be used, 'dry' or 'wet', to get the beans to the 'parchment' stage: within their hulls with most of their moisture removed. They can be stored in this state prior to processing to remove the hull, after which they are sorted and graded and ready for export around the world.
Two important developments in coffee production have arisen in this century: instant coffee and the decaffeination process.
lnstant coffee is made by spray or freeze drying a coffee brew to remove the water, resulting in powder or granules which are reconstituted simply by adding hot water.
Commercial coffee decaffeination processes were initiated in Germany during the early part of the 20th century. Today there are a variety of different methods employed to remove the caffeine from coffee beans, with all processes safely and selectively removing about 97-98% of the caffeine. The process of decaffeination is carried out while the beans are still 'green', before they are roasted and the aroma develops.
The three main methods are: water decaffeination; carbon dioxide decaffeination and solvent decaffeination. The first two methods are now used by major manufacturers. While solvents are still occasionally used, they are governed by both national and European legislation. Solvents include methylene chloride (dichloromethane) and ethyl acetate (which occurs naturally in fruits and other foods). Under European law, methylene chloride residue levels must be under 2 parts per million.
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