What Are the Varieties and Derivatives of Coffee Beans? What Are the Main Components and Their Functions?

Coffee Bean Varieties and Derivatives: Main Components and Their Functions

The Three Original Species of Coffee

Arabica

The Arabica variety originates from the Ethiopian highlands, where it was initially used as medicine. Roasting as a practice developed in the 13th century, and by the 16th century the beans had been carried to Europe through Arab traders, becoming a popular beverage across the continent. Following the footsteps of European colonists, it eventually became one of the most popular beverages worldwide.

Robusta

Robusta was discovered in the Congo region of Africa. It resists leaf rust disease far better than Arabica, but its flavor is so overpowering that few people drink it straight. Typically, when just 3-4% of Robusta beans are blended into a cup of coffee, the entire cup tastes like Robusta.

Liberica

Liberica is mainly produced in West Africa. It adapts extraordinarily well to its environment but cannot withstand leaf rust, and its flavor falls short of Arabica's. As a result it circulates almost entirely within West African countries such as Liberia and Ivory Coast, and it is difficult to find on the international market. Its beans have a distinctive spoon-like shape.

Coffee Bean Components

Water, protein, fat, carbohydrates (sucrose), chlorogenic acid, caffeine, and amino acids are the main factors affecting the color, aroma, and flavor of coffee beans.

Knowledge Extension: Caffeine accounts for 0.9%-1.4% in Arabica varieties, while Canephora (Robusta) typically runs about 2%, sometimes exceeding 3%.

FrontStreet Coffee Recommendation

Ethiopia, the birthplace of Arabica, is a treasure trove of native varieties—with countless uncatalogued coffee trees still growing wild. FrontStreet Coffee's washed Yirgacheffe is the ideal introduction: the town sits in the south of the country, cool, misty, and spring-like year-round, where thousands of coffee trees thrive and produce that signature interweaving of florals and fruit acidity. The cup is light and elegant with a tea-like quality, like a refreshing, clean lemon tea.

Most Ethiopian coffee follows a "garden cultivation" model: each smallholder delivers freshly harvested cherries to a village-level processing station, and the coffee is sold under the team's name—which is why cooperative lots abound. The Guadingding (Idido) cooperative in the Worka area, independent since 2012 with roughly 300 member farmers, skins the cherries before drying so the beans' own character comes through crystal clear: citrus and lemon tones with elegant white florals. The natural-process Red Cherry Yirgacheffe goes the opposite route, sun-drying whole cherries for two weeks until moisture drops to 12%, then milling and triple-sorting the beans—yielding pristine lots with peach, cocoa, honey, and lemon. From Sidamo's Guji zone, the natural Hibiscus (Huakui) comes from a 200-hectare farm in Hambella, where cherries dry on raised beds for 21 days with regular turning and manual defect removal every three to five days; a medium-light roast reveals faint fermented wine notes, florals, citrus, and mango, with honeyed sweetness, cocoa, spice, and a thick, lasting finish.

For something off the beaten path, the Hamasho washing station's 74158 lot—bred by the Jimma Agricultural Research Center (JARC)—is small-beaned but intensely aromatic: perfume lemon, strawberry, star fruit, and green grape sweetness followed by delicate florals. And the Kaffa Forest coffee, grown wild at 1,400-2,100 meters under shade, offers white florals, bright lemon acidity, sweet orange and bergamot, and a green-tea-like finish.