The word "coffee" entered the English language in 1582 via the Dutch koffie, borrowed from the Ottoman Turkish kahve, in turn, borrowed from the Arabic qahwah (قهوة). The Arabic word qahwah was traditionally held to refer to a type of wine whose etymology is given by Arab lexicographers as deriving from the verb qahiya (قَهِيَ), "to lack hunger", in reference to the drink's reputation as an appetite suppressant. It has also been proposed that the source may be the Proto-Central Semitic root q-h-h meaning "dark".
Alternatively, the word Khat, a plant widely used as a stimulant in Yemen and Ethiopia before being supplanted by coffee has been suggested as a possible origin, or the Arabic word quwwah' (meaning "strength"). It may also come from the Kingdom of Kaffa in southeast Ethiopia where Coffea arabica grows wild, but this is considered less likely; in the local Kaffa language, the coffee plant is instead called "bunno".
Coffee traces its origin to a genus of plants known as Coffea. Within the genus there are over 500 genera and 6,000 species of tropical trees and shrubs. Experts estimate that there are anywhere from 25 to 100 species of coffee plants. The genus was first described in the 18th century by the Swedish botanist, Carolus Linnaeus, who also described Coffea Arabica in his Species Plantarum in 1753. Botanists have disagreed ever since on the exact classification, since coffee plants can range widely. They can be small shrubs to tall trees, with leaves from one to 16 inches in size, and in colors from purple or yellow to the predominant dark green. In the commercial coffee industry, there are two important coffee species – Arabica and Robusta.
Coffea Arabica is descended from the original coffee trees discovered in Ethiopia. These trees produce a fine, mild, aromatic coffee and represent approximately 70% of the world's coffee production. The beans are flatter and more elongated than Robusta and lower in caffeine. On the world market, Arabica coffees bring the highest prices. The better Arabicas are high grown coffees – generally grown between 2,000 to 6,000 feet (610 to 1830 meters) above sea level –though optimal altitude varies with proximity to the equator. The most important factor is that temperatures must remain mild, ideally between 59–75 degrees Fahrenheit, with about 60 inches of rainfall a year. The trees are hearty, but a heavy frost will kill them. Arabica trees are costly to cultivate because the ideal terrain tends to be steep and access is difficult. Also, because the trees are more disease-prone than Robusta, they require additional care and attention.
Most of the world's Robusta is grown in Central and Western Africa, parts of Southeast Asia, including Indonesia and Vietnam, and in Brazil. Production of Robusta is increasing, though it accounts for only about 30% of the world market. Robusta is primarily used in blends and for instant coffees. The Robusta bean itself tends to be slightly rounder and smaller than an Arabica bean. The Robusta tree is heartier and more resistant to disease and parasites, which makes it easier and cheaper to cultivate. It also has the advantage of being able to withstand warmer climates, preferring constant temperatures between 75 and 85 degrees Fahrenheit, which enables it to grow at far lower altitudes than Arabica. It requires about 60 inches of rainfall a year, and cannot withstand frost. Compared with Arabica, Robusta beans produce a coffee which has a distinctive taste and about 50-60% more caffeine. In 5-10% of the coffee crop, the coffee cherry will contain only one seed, or bean. These single beans are round (like a pea) instead of flattened on one side the way normal twin-seeded are. Peaberries used to be discarded as defects, but then people realized that they have a particular intensity of flavor that comes from being a single bean. Peaberries have extra edge and a bit more caffeine. In Vietnam, the peaberry is highly prized, and their Robusta has been selectively bred to produce a higher percentage of peaberries.
Excelsa was recently re-classified as a variety of Liberica. However, even though the plants may be taxonomically similar, the actual coffee is so dramatically different that we still think of them as entirely separate species. It accounts for about 7% of world coffee production. It grows on large, vigorous trees at medium altitudes. Many beans have a distinctive "teardrop" shape, which gives it a family resemblance to Liberica, but their average size is much smaller.
A unique and irreplaceable part of our worldwide coffee heritage, Liberica is an entirely separate species of coffee, with a very distinctive taste profile. It grows on vigorous 20-30-foot trees in jungle environments – which is fortunate, because if it weren’t strong enough to grow wild, it would have gone extinct. The type of men who worked in the nearby sugar cane fields drank a lot of coffee to keep up their energy during their hard work.