There are basically two types of coffee beans that are commonly used: Arabica and Robusta. There are numerous varieties of plants that are coffee species, but these two are the most important from a commercial point of view. A third species can be good as well, which is Liberica (from Liberia), but on the global market, it is less important.
Coffee beans are the seeds of a cherry-like fruit. The seeds are covered by different layers of skin, which all have their specific roles. Before the roasting process, all these skins have to be eliminated. Sometimes, there are skins that remain.
There are many countries of origin for the seeds and numerous types of flavors can be applied to the seeds, through roasting. The pulp can be taken out from the bean in two ways: wet processing and dry processing.
Arabica Coffee Beans
Arabica is a special variety, because it has four chromosome sets, while Robusta and Liberica have two. More than sixty five percent of world coffee cultures are of Arabica, but many of them are not top quality. The taste of Arabica can be different, according to the location in which is grown. Examples of tastes can be the ones that are similar to berries (Ethiopian coffee), earthy (Indonesia and India), chocolate, or citrus (Central America). The best conditions to grow Arabica are at low altitudes, such as one thousand feet in Hawaii, four thousand feet in Mexico and between three thousand five hundred and nine thousand five hundred at the Equator.
Robusta Coffee Beans
This variety was called canephora in the past and its tastes are not as good as the ones of Arabica. Premium quality products from this variety are used more for espresso blends. Robusta has more fruit, a lower cost, grows well at lower altitudes and is more resistant to diseases. When taste is involved, this is a subjective factor, because some people may find a coffee variety tasteful, while others may not.
Robusta can be sometimes comparable to Arabica, but quality beans of this type can be hard to find. It is rarely sold alone, as in many cases it is used as an ingredient for enhancing another product. The caffeine content is much higher than the one found in Arabica.
The Roasting Process
Before the roasting process, coffee beans are green, but they become brown after. Through roasting, green seeds can expand and change their taste, aspect, smell and taste. The main purpose of roasting is providing a longer shelf life for the benefit of the distributor and the consumer. Some people prefer to make their own roasting at home, but most world coffee is roasted in large scales. There are various levels of roasting, from light to dark. The lighter ones are more acidic and sharper.
Common roasting levels are: American Light, New England, Cinnamon, Full City, City Medium, Italian Dark French, Spanish and French Espresso. Cinnamon is light brown and has the flavor of baked bread. American light is medium brown. New England is darker than Cinnamon. Full City is medium dark brown. The rest are dark, but the darkest one of all is the Spanish roast, because its color is almost black.
Decaffeinated versions are made by eliminating caffeine from regular coffee. One of the disadvantages of the versions is that they lose much of the flavor, which is given by caffeine itself. One of the main processes of obtaining coffee that is free of caffeine is soaking the beans, while they are green, into hot water. A solvent is used for decomposing the caffeine and extracting it out. Usually, ethyl acetate or methylene chloride, are the ingredients. There are other methods but this is the most common. It is known that there is no decaffeinated coffee that is totally free of caffeine.
General Growing Conditions
No matter what types of coffee beans are produced, the soil has to be well-drained, but moist. The best environment is one that is well lit and in which there are forest shadows around as well. There are hybrids nowadays that perform very well in full sunlight. However, these ones have other disadvantages. Fungus and insects can be enemies of Arabica and there are also concerns regarding leaf rust and various pesticides. A coffee tree reaches full maturity in four years.