What Is Coffee? The Story of the Rubiaceae Shrub

If you’ve ever wondered what kind of plant gives us our daily coffee, you’re not alone. Most people can name a coffee drink or roast, but few know the actual species of plant behind their cup—or how a shrub from East Africa became the second-most traded commodity in the world. The story starts not with a roaster, but with a wild-growing plant in the highlands of Ethiopia.

Coffee (Coffea arabica) is a small evergreen shrub from the Rubiaceae family. It’s the source of the beans we roast and brew. Arabica makes up over 60% of global production and grows best at higher altitudes. There are other species too, like Robusta and Liberica—but arabica is the one most coffee lovers seek out for its balanced, nuanced flavours.

The Origins and Botany of Coffee

Coffee’s scientific name is Coffea arabica, but it didn’t start there. Originally from the Kaffa region of Ethiopia, the plant was first cultivated in Yemen by the 6th century. The word ‘coffee’ derives from the Arabic ‘Qahwah’, meaning a plant-based drink. It later took the name ‘Kaffa’ from its origin region before becoming ‘coffee’ in English by the 18th century.

In botanical terms, coffee is a small evergreen shrub or small tree belonging to the Rubiaceae (or madder) family. It has horizontal, opposite-growing side branches—sometimes in whorls of three. Its leaves grow in pairs, and flowers appear in clusters of 2–10 in leaf axils. The fruit is a drupe, oval-shaped, starting dark green and ripening to yellowish-red or purplish-red. Each fruit contains an outer skin, pulp, parchment layer (called the endocarp), silver skin, and finally, at the centre, the seed: the coffee bean.

How Coffee Spread Across the World

The first wild coffee plants were found in the Horn of Africa. By the 15th century, cultivation had begun, and for centuries, Yemen was the only source of coffee in the world. So valuable was the crop that armed guards protected shipments leaving the port of Mocha. Yemen even restricted the export of live coffee plants. Yet, Muslim pilgrims smuggled seeds out, and coffee soon reached India. European merchants trading in Venice brought coffee westward, and by the streets of Paris and Vienna, it quickly gained popularity. Dutch traders introduced it to Indonesia in the 17th century, while the French started planting it in Africa.

Today, coffee is the second-most traded commodity globally, after oil. Among the many legends surrounding its discovery, two stand out: the ‘story of the shepherd’ and the ‘tale of the Arabian monks’. Both involve the energising effects of the red coffee cherry and its transformation into a brewed drink.

Major Coffee-Growing Regions and Varieties

The primary coffee-growing regions are Africa, Indonesia, and Central and South America. Yemen was the first country to cultivate coffee commercially, and to this day, some Yemeni farmers resist modern chemical inputs, growing coffee under shaded trees planted along steep terraced hillsides to conserve water and maximise yield. Coffee in Yemen is still transported in traditional straw sacks, not synthetic bags.

Globally, coffee is cultivated in 76 countries. The main cultivated species are:

• Arabica (Coffea arabica) – Also called ‘small bean’ or ‘Yemen coffee’, makes up most specialty coffee.
• Robusta (Coffea canephora) – Known as ‘medium bean’, higher in caffeine, more bitter, often used in espresso blends.
• Liberica (Coffea liberica) – Called ‘large bean’, rare and with a unique, woody flavour.

Arabica itself includes many cultivated varieties like Typica, Bourbon, Geisha, and others—all with distinct flavour profiles based on terroir.

The History and Global Journey of Coffee

The word ‘coffee’ may come from Kaffa, Ethiopia, and the Greek ‘Kaweh’ meaning ‘strength and vigour’. Legends say a goatherd noticed his flock became energetic after eating red berries. Monks then used the berries to stay awake during prayers. Arabs initially used coffee as a medicinal drink before it became a social staple.

As the Ottoman Empire expanded, coffee travelled into Europe via Vienna and Paris. Colonists later spread it worldwide—Dutch to Indonesia, French to the Americas, and eventually to Brazil, which became the world’s largest producer by the 19th century. Brazil’s coffee boom began around 1727 and shifted from Rio to São Paulo by 1800, where ideal conditions helped coffee become central to the economy.

By the mid-1800s, coffee planting had spread widely across Central and South America, cementing the region’s role in global supply.

Coffee Species and What’s Inside the Bean

The coffee plant is part of the Rubiaceae family and typically grows as a small tree or large shrub, reaching 5–8 metres. Leaves are glossy, oval, and arranged oppositely. Small white flowers give way to red berries, each holding two seeds—the coffee beans.

Coffee chemistry is complex. Beans contain caffeine (a stimulant), tannins, fats, proteins, sugars, acids, and minerals. These elements influence flavour, aroma, body, and mouthfeel. For example:

• Caffeine: Provides stimulation and has a bitter taste.
• Tannins: Can cause bitterness if over-extracted.
• Sugars: Caramelize during roasting, contributing to sweetness and colour.
• Fats: Contribute to crema and mouthfeel.
• Acids: Give brightness and complexity.

Each 100g of green coffee beans contains approximately: 2.2g water, 12.6g protein, 16g fat, 46.7g carbohydrates, 9g fibre, 4.2g ash, and a range of vitamins and minerals including calcium, iron, phosphorus, and sodium. Roasted coffee has less moisture and altered nutrient profiles.

Main Coffee Varieties You Should Know

Beyond species, coffee comes in varieties with distinct characteristics:

• Typica: The original arabica variety, balanced and clean.
• Bourbon: Sweet and complex, common in Latin America.
• Geisha: Floral, tea-like, and highly prized.
• Mandheling: Full-bodied and earthy, from Indonesia.
• Blue Mountain: Mild, balanced, grown in Jamaica’s highlands.
• Yellow Bourbon: Sweeter and fruitier due to orange-coloured fruit.

These varieties adapt differently across regions, producing the diverse flavour profiles coffee lovers cherish.

Frequently Asked Questions

What family does the coffee plant belong to?

The coffee plant belongs to the Rubiaceae family, also known as the madder or bedstraw family. This family includes many flowering plants, and coffee (Coffea arabica) is one of its most economically important members.

Where did coffee originally come from?

Coffee originated in the Kaffa region of Ethiopia. The earliest wild coffee plants were found there, and cultivation later spread to Yemen by the 6th century, where it was first commercialised.

What are the main species of coffee?

The three main coffee species are Arabica (Coffea arabica), Robusta (Coffea canephora), and Liberica (Coffea liberica). Arabica is the most widely grown and prized for its quality, while Robusta is more bitter and higher in caffeine.

What does a coffee fruit contain?

A coffee fruit (cherry) contains an outer skin, pulp, a parchment layer, a thin silvery skin, and two seeds (coffee beans) at the centre. The beans are the only part used for brewing coffee.

Why is Arabica coffee so popular?

Arabica coffee is popular because it offers a more complex, nuanced flavour profile compared to Robusta. It grows at higher altitudes, has less caffeine, and is less bitter, making it the preferred choice for specialty coffee.

How did coffee spread around the world?

Coffee spread through trade and cultural exchange. It moved from Ethiopia to Yemen, then to the Middle East. Pilgrims and traders carried it to India, Europe, and eventually to Dutch colonies in Asia and French colonies in Africa. Brazil later became the dominant producer.

Recommended FrontStreet Beans for Exploring Arabica

Start your journey into arabica coffee with FrontStreet’s Ethiopia Yirgacheffe Gedeb Cooperative (washed), offering bright citrus and floral tones; Jamaica Blue Mountain No.1 (Typica), a balanced classic with chocolate and nuts; and Strawberry Candy Geisha, a vibrant, fruity, and floral profile. These beans showcase the diversity and quality of the arabica species. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.