What Are Coffee Beans? The Plant, Process & Global Trade

If you’ve ever wondered where your morning coffee actually comes from, the answer begins with a small evergreen shrub native to the tropics of Africa. More than just a beverage ingredient, coffee beans have shaped global trade, medicine, and daily life for over two millennia. But how did a plant from Ethiopia become the world’s most traded tropical commodity?

Coffee beans come from the Coffea plant, a perennial evergreen shrub or small tree in the Rubiaceae family. Cultivated for over 2,000 years, it originated in Africa’s tropical highlands and remains the source of the world’s most widely consumed beverages. Today, coffee is the leading global beverage crop by production, trade value, and consumption.

What Is the Coffee Plant?

The coffee plant belongs to the genus Coffea, specifically the Rubiaceae (or madder) family. It grows as a perennial evergreen shrub or small tree and thrives in tropical and subtropical climates. Native to the highland regions of Africa, it has been cultivated for more than 2,000 years. Historical records show Arabs began planting coffee as early as 525 BCE, initially roasting and eating the beans. Large-scale cultivation started in the 15th century, and by the 18th century, coffee had spread across Europe, Asia, Africa, and Latin America’s tropical and subtropical zones.

How Coffee Beans Are Used

Coffee beans are primarily used to make brewed coffee, one of the most popular drinks worldwide. Beyond drinking, coffee beans are also a source of pharmaceutical compounds. They can be processed to extract caffeine, which functions as a stimulant, diuretic, anesthetic, and cardiac agent. This dual role—as both a beverage ingredient and medicinal compound—adds to the plant’s global significance.

From Fruit to Bean: How Coffee Is Processed

Coffee beans are the seeds inside the fruit of the Coffea plant, commonly referred to as coffee cherries. There are two main methods to turn these cherries into the green beans used for roasting: dry processing and wet processing.

Dry Processing (Natural Method)

This simpler method involves drying the entire coffee cherry in the sun or using electric drying equipment. Once dried, the outer fruit layers—including the pulp and parchment—are removed through threshing and screening, leaving behind the green coffee bean ready for export or roasting.

Wet Processing (Washed Method)

Used in most producing regions, this method yields higher-quality beans. The steps include:

• Rinsing fresh coffee cherries in water
• Removing the skin with a pulping machine
• Fermenting the beans to break down the mucilage (1–1.5 days for Arabica, 1.5–2 days for Robusta, depending on climate)
• Washing off residual mucilage
• Drying the beans (either in the sun or using mechanical dryers)
• Removing the parchment layer
• Sorting and grading the final green coffee beans

Fermentation time is critical: too long results in sour flavors, while too short leaves sticky mucilage that causes uneven drying and poor bean quality.

Global Coffee Production & Trade

Coffee ranks as the world’s number one beverage crop by production volume, trade value, and consumption. Major production regions include South and Central America, Africa, Asia, and Oceania, with most exports originating from Central and South America. The United States is the largest coffee importer, followed by Japan, Italy, Canada, Sweden, Austria, Switzerland, Singapore, Finland, and Norway.

The global coffee trade mainly deals in four products: green (raw) coffee beans, roasted beans, ground coffee, and instant coffee—with green beans making up the bulk of the trade.

In China, coffee cultivation began in Taiwan in 1884 and later expanded to Hainan, Guangdong, Fujian, Guangxi, and Yunnan. Annual production is around 2,600 metric tons, but domestic demand relies heavily on imports—approximately 12,000 metric tons of green beans and 700–800 metric tons of coffee products yearly. Major import sources include Brazil, Colombia, Kenya, and Ethiopia. China also exports a small amount, about 2,000 metric tons annually.

Coffee Species & Varieties

There are four main cultivated coffee species, each with distinct characteristics:

1. Arabica (Coffea arabica, “” or Small Bean Variety)

Originating in Ethiopia, Arabica is a small evergreen shrub known for its sweet fruit, mild flavor, and lower caffeine content. It makes up over 80% of global production and is cultivated mainly in Brazil and Colombia. Its beans are typically smaller with thicker skins.

2. Robusta (Coffea canephora, “” or Medium Bean Variety)

Native to the Congo rainforest, Robusta is a small tree producing oval or elliptical fruits that mature purple. Its beans have thin, tightly adhering parchment, a stronger, more bitter taste, and higher caffeine content. It’s mainly grown in Southeast Asia, India, and Africa.

3. Liberica (Coffea liberica, “” or Large Bean Variety)

This tall tree species from Liberia produces large, elongated fruits that ripen to a reddish-orange color. Its flavor is intense but considered inferior in cup quality, and it’s rarely cultivated outside Liberia, Malaysia, and Indonesia.

4. Excelsa / Ethereal (Coffea liberica var. dewevrei / Coffea stenophylla, “”)

Originating near the Chari River in Africa, this variety produces small fruits with a strong, slightly bitter flavor. It’s rarely cultivated.

Globally, Arabica and Robusta dominate the market, with Arabica being the clear leader.

Coffee Bean Structure & Morphology

A coffee cherry is a drupe (stone fruit) that typically contains two seeds (beans). Each cherry measures about 9–14 mm in length and turns red or purple when ripe. The bean is surrounded by several layers:

• Outer skin (exocarp)
• Pulp (mesocarp)
• Parchment (endocarp or “”)
• Silver skin (seed coat)
• Bean (endosperm or “”)

The silver skin-covered bean is what we call the “green coffee bean” once processed. The color and thickness of the parchment layer help distinguish coffee varieties.

Coffee Bean Quality Standards

Imported green coffee beans are graded by specific quality criteria. A simplified version of the contract standards includes:

Chemical Composition of Coffee Beans

Coffee beans are made up of various chemical components, including:

• Proteins
• Fats (lipids)
• Carbohydrates (starch, glucose, sucrose)
• Fibers
• Minerals (ash)
• Caffeine

For Arabica green beans, typical values include: 15.94% protein, 18.24% fat, 7.83% sucrose, 5.80% starch, 1.27% caffeine, 13.77% crude fiber, 3.62% ash, and 2.55% total nitrogen. Roasted beans show slight reductions in some components like caffeine (1.31%) and increases in others like fat (11.97%).

Inspection & Standards

Imported coffee beans are inspected according to contract specifications or, where absent, industry standards. In the absence of local standards, ISO norms are referenced, including:

• ISO 1446: Moisture content (reference method)
• ISO 1447: Moisture content (routine method)
• ISO 4072: Sampling of bagged green beans
• ISO 4149: Sensory and visual defect inspection
• ISO 4150: Sieve analysis by hand

Additional national food safety standards may apply for contaminants such as copper, lead, aflatoxins, and pesticide residues.

Storage & Packaging

Green coffee beans are typically packed in jute or burlap sacks that must be clean, intact, and free of odor, pests, or rodent damage. Storage and transport conditions should ensure cleanliness and protection from foreign odors or contaminants.

Recommended FrontStreet Coffee Beans for Exploring Origins

Explore the origins of coffee with FrontStreet Coffee’s single-origin offerings. The Ethiopia Yirgacheffe showcases floral and citrus notes with bright acidity, perfect for experiencing the classic Arabica profile. For something more robust, try the Colombia Huila, which balances caramel and nuttiness with medium acidity. Finally, the Sumatra Mandheling offers earthy and spicy complexity, highlighting the qualities of processed Robusta-influenced beans. All are excellent for learning how processing and origin shape flavor. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.