What You Need to Know About Coffee Trees and Arabica Varieties

Ever wondered where your morning coffee actually comes from? Not the bag on the shelf, but the actual plant? The journey of every coffee bean starts on a living, growing coffee tree—often in high-altitude, tropical regions with very specific environmental needs. Understanding how these trees grow, what they need, and how different varieties behave is key to appreciating the complexity behind every cup.

Coffee trees—scientifically known as Coffea arabica and Coffea canephora (Robusta)—are woody, evergreen perennials that produce the seeds we roast as coffee beans. Arabica trees, the premium choice, thrive at higher altitudes between 1,000–2,000 metres and demand cooler temperatures, while Robusta grows at lower elevations and is more disease-resistant but less flavourful.

What Is a Coffee Tree?

The coffee tree (Coffea arabica) is a tropical evergreen shrub or small tree belonging to the Rubiaceae (madder) family. It is cultivated as a perennial cash crop prized for fast growth, high yields, and economic value. In the wild, coffee trees can reach 5–10 metres in height, but cultivated trees are pruned to under 2 metres to boost yields and ease harvesting.

The tree features oval, smooth leaves that grow opposite each other, with long terminal branches and sparse branching. Small white flowers bloom at the base where leaves meet stems. The fruit—commonly called a coffee cherry—resembles a bright red cherry when ripe. Inside each cherry are usually two seeds, which we call coffee beans.

Arabica vs. Robusta: The Two Main Coffee Species

Coffee is broadly divided into two main commercially grown species: Arabica (Coffea arabica) and Robusta (Coffea canephora). There are also minor species like Liberica (Coffea liberica) and Arabusta (a hybrid), but these are rarely seen in the market.

Robusta beans are rounder, have a straighter, more pronounced furrow, and a flatter profile reminiscent of soybeans. In contrast, Arabica beans are more oval, with a curved groove resembling half a peanut. Robusta is generally considered to have a simpler, harsher flavour, but it contains 2–3 times more caffeine. It’s commonly used in instant coffee and commercial blends due to its low cost and high yield. Arabica, on the other hand, offers more complex flavours and aromatic qualities, making it the preferred choice for specialty coffee.

Most of the coffee sold worldwide is a blend of Arabica and Robusta—often around 70% Robusta (for caffeine) and 30% Arabica (for flavour). However, quality-focused roasters lean heavily on Arabica varieties.

Growing Conditions for High-Quality Coffee

Coffee trees require very specific conditions to produce high-quality beans. Ideal growing temperatures range from 15–25°C, and annual rainfall should be between 1,500–2,000 mm, ideally timed to coincide with the tree’s flowering cycle. Well-drained, fertile soils—especially those rich in volcanic ash—are essential. While coffee plants need sunlight, too much direct sun can hinder growth, so shade trees are often planted alongside coffee.

The optimal altitude for Arabica is between 500–2,000 metres, where cooler temperatures slow maturation, allowing beans to develop more complex flavours. Robusta, however, thrives at lower altitudes and in hotter, more humid conditions.

Not all regions within the “coffee belt” (between the tropics of Cancer and Capricorn, roughly 25°N to 25°S) can grow great coffee. Microclimates, elevation, soil quality, and farming practices all play crucial roles in determining bean quality.

From Flower to Coffee Cherry

A coffee tree typically begins flowering when it’s around three years old. The flowers are small, white, and shaped like five-petaled tubes, giving off a light jasmine-like fragrance. They bloom in dense clusters and usually fall off after two or three days, making way for fruit development a few months later.

The coffee fruit, known as a coffee cherry, is a drupe about 1.5 cm in diameter. It starts off green, then turns yellow, and finally ripens to a bright red—similar to a cherry—which is why it’s often called a “coffee cherry.” Each cherry normally holds two seeds (the coffee beans) that sit facing each other, flat sides touching. The beans are encased in a thin, papery layer called the silverskin, surrounded by a yellowish parchment layer (endocarp), all embedded in sweet, sticky mucilage and encased in an outer skin.

The Origins of Coffee

Coffee originated in the Kafa Forest region of southwestern Ethiopia. The word “coffee” itself is derived from “Kaffa,” the name of the province where wild coffee still grows in dense forests. Though coffee is now cultivated in 76 countries, with Brazil being the largest producer, Ethiopia remains the birthplace of the plant.

Legends abound about how coffee was first discovered. One tale from the 13th century tells of an Ethiopian prince who noticed his goats became unusually energetic after eating red berries from a certain bush. After trying them himself, he experienced a similar boost. Another story describes a 9th-century Ethiopian shepherd whose flock became hyperactive after eating red fruits from a small tree. Intrigued, he tried the fruits himself and felt unusually alert.

Historical records show that Arabs began cultivating coffee as early as 525 CE, chewing roasted beans for stimulation. By 890 CE, coffee reached Yemen, where it was first brewed into a drink. From there, it spread to Europe, Asia, and the Americas. By the 18th century, coffee had become a global commodity and one of the world’s three most consumed beverages—outranking tea and cocoa in sales.

China’s coffee cultivation began much later, in the late 19th century, with Taiwan planting the first coffee trees in 1884. Hainan followed in the early 20th century, and by the mid-1900s, southern provinces started growing coffee. Despite its shorter history, regions like Yunnan are now recognised for producing high-quality Arabica beans, particularly noted for their vibrant acidity, rich body, and fruity notes. These beans are often exported after processing and command premium prices on the international market.

Coffee Bean Basics

What we call a “coffee bean” is actually the seed of the coffee fruit. Shaped somewhat like a bean, it’s found inside the coffee cherry. The bean has several layers: the outer skin, the sweet pulp, a layer of mucilage, the parchment (endocarp), the silverskin (thin membrane), and finally, the green coffee bean inside.

The silverskin is a thin, shiny layer that clings tightly to the bean. The parchment is a yellowish, protective husk, and the pulp is soft and sugary when the cherry is ripe. All these layers must be removed during processing to reveal the green coffee bean used for roasting.

Recommended FrontStreet Beans for Exploring Arabica Diversity

Start exploring the world of Arabica with FrontStreet Coffee’s standout single origins. The Ethiopia Gedeb Yirgacheffe (Gedeb) showcases bright citrus and floral notes with a juicy profile, thanks to its Typica-influenced genetics and high-altitude growing conditions. For a classic balanced cup, try Jamaica Blue Mountain No.1 (Typica)—renowned for its smooth chocolate, almond, and creamy body. If you’re after exotic florals and stone fruit, the Strawberry Candy Espresso (Geisha) delivers intense rose, grape, and apricot tones with a silky mouthfeel. All are expertly roasted to highlight their natural qualities. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.