THE TWO MOST COMMON COFFEES
“Raw coffee beans are the seeds of plants belonging to the Rubiaceae family, which comprises at least 66 species of the genus Coffea,” says the journal Scientific American. “The two species that are commercially exploited are Coffea arabica, which accounts for two thirds of world production, and C[offea] canephora, often called robusta coffee, with one third of global output.”
Robusta coffee has a strong, earthy aroma and usually ends up in soluble form in instant coffees. The tree is high yielding and disease resistant. It grows to about 40 feet [12 m], double the height of the unpruned, more delicate, and lower-yielding arabica tree. By weight, the robusta bean has up to 2.8 percent caffeine, whereas arabica never exceeds 1.5 percent. Even though arabica has 44 chromosomes and robusta and all wild coffees have 22, some have been crossed to produce hybrids.