Before discussing specific types of coffee beans. Lets first talk about the Coffee Plant. Coffee trees are not really trees at all as Botanically they are “shrubs” The coffee plant is part of theRubianceae family native to the mountains of Yemen in Arabia.
While there are over seventy-three classified species of the Coffee Plant, only three are used in significant quantities for commercial coffee production. Those three varieties in which virtually all coffee sold is derived from area arabica, robusta, and liberica.
Arabica is the original coffee plant discovered and cultivated for coffee. It gets its name from the plants origin region, the Yemen Mountains in Arabia. Of the three main coffee varieties, Arabica is considered to have the best flavor, yet least amount of caffeine. Virtually all arabica coffee is hand-picked. This is mainly due to the height of the plant. Arabica plants can grow up to 20 feet and human pickers can choose the ripest beans at the top. There are two varieties of arabica where all other cultivars are derived from. These varieties are known as Bourbon and Typica.
Robusta (Coffea canephora) is typically found in espresso blends. That latte or mocha you buy at Starbucks is made mostly of robusta type coffee beans due to its high concentration of caffeine and body. For a long time coffee growers through out the world tried to replace arabica touting robusta as the better coffee bean. Of course, this was due to profit considerations more than the quality or flavor profile. Because the Robusta plant needed lest space between them than arabica plants, coffee growers had higher yields per acre resulting in more crop. In addition, the robusta plant was far more disease resistant resulting in lower crop loss. When you also add in the fact that the robusta plant was shorter, making coffee picking easier and less costly, you can see why for years the coffee growers marketed robusta so heavily.
Robusta was an ideal coffee plant for mass if you discounted consideration for flavor. As a comparison, the highest grade robusta would be on par with only a low grade arabica. Robusta is great cash crop but it does not afford the nuanced flavor profile found in arabica coffee. If you want the best coffee in the world, you must search for arabica beans.
Liberica (Coffea Liberica) is grown predominantly in South East Asia. You will be hard pressed to find it in the United States or Europe. Liberica became popular in the late 19th century due to its resistance to a coffee killing disease called leaf rust that was destroying fields of arabica coffee plants. Eventually hardier, more-disease resistant arabica varieties were bread and discovered resulting in the decrease of Liberica plantings. Liberia was never a serious competitor to arabica or robusta plants. Liberica’s flavor profile is significantly inferior to arabica and the Liberia plant produces much less coffee than robusta, the primary commodity coffee.