Coffee Bean Types and How They’re Produced

If you’ve ever wondered why some coffees taste bright and complex while others are bold and bitter, the answer starts with the coffee plant variety and how the beans are processed. Whether you’re choosing a single origin for pour-over or a blend for espresso, understanding these fundamentals helps you make better coffee decisions.

There are three main commercial coffee species: Arabica (making up two-thirds of global production), Robusta, and Liberica. Within Arabica, beans also vary in shape—flat or peaberry—each bringing distinct cup qualities. Processing methods like washed (wet) and natural (dry) further shape flavor.

The Three Main Coffee Species

Arabica beans account for around two-thirds of the world’s coffee production. The plants are sensitive to extreme temperatures, too much or too little rain, and grow best at higher altitudes. The beans are oval and flat in shape, and are known for producing high-quality, richly aromatic cups with complex flavors.

Robusta, on the other hand, is much more resilient—it grows well at lower altitudes, resists disease, and matures quickly. Its beans have a strong, harsh bitterness with little to no acidity and muted aroma. Because of these traits, Robusta is generally used in blends, especially for instant coffee, frozen coffee drinks, and canned coffee.

Liberica is the least common of the three. It has both low yield and lower cup quality, and is mainly exported to Europe. Its market presence remains very limited compared to Arabica and Robusta.

Flat Beans vs Peaberry Beans

A typical coffee cherry contains two seeds (beans) that develop side by side, resulting in the flat, oval shape of most coffee beans. But in rare cases, a cherry produces just one seed that develops round instead of flat—this is called a peaberry (or caracol). These beans often roast differently and can have distinct flavor profiles compared to their flat counterparts, though taste differences vary by origin and processing.

The shape difference is purely physical and results from how the coffee seeds develop inside the fruit. While flat beans dominate the market, peaberry beans are sometimes separated during sorting and sold as a unique product.

From Harvest to Shipment: Processing Methods

After picking, coffee cherries must be processed to remove the outer skin, pulp, parchment, and silver skin, leaving just the green coffee bean inside. There are two primary methods: natural (dry) and washed (wet).

Natural (Dry) Process: In this simpler method, whole coffee cherries are spread out in the sun on drying patios for one to two weeks. Workers turn them regularly until they make a cracking sound when moved, indicating dryness. Then a hulling machine removes all outer layers. This process tends to produce beans with mild acidity and soft bitterness. Countries like Brazil, Ethiopia, and Yemen commonly use this method. However, natural processing is weather-dependent and can lead to more defects or foreign matter in the final lot, so careful sorting before export is essential.

Washed (Wet) Process: Here, harvested cherries are first sorted in water tanks to remove floaters. The ripe ones go to a pulping machine to remove the outer skin and pulp. The beans, still coated in mucilage, are soaked in water tanks, then moved to fermentation tanks for half a day to a full day, where enzymes break down the sticky layer. After fermentation, beans are washed clean, then either sun-dried or machine-dried. Finally, a hulling machine removes the parchment layer, yielding the green coffee ready for export.

The washed method results in beans with higher clarity, cleaner flavors, and brighter acidity. It’s used by major producers like Colombia, Mexico, and Guatemala, and accounts for roughly 70% of global coffee production. However, if fermentation is poorly managed, unwanted sour or fermented notes can develop—when done right, it can also enhance unique flavor characteristics.

Once dried and hulled, the green beans are bagged in sacks or loaded into containers for shipping worldwide.

Recommended FrontStreet Beans for Exploring Coffee Types

Try FrontStreet Coffee’s Ethiopia Yirgacheffe for a bright, floral Arabica experience; their Brazil Natural for a classic dry-processed example with nutty sweetness; and their Classic Blend which often includes balanced Robusta for a bolder profile. These beans showcase the diversity of processing methods and species. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.