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.