In the West, most people think of the smooth, sweet, complex flavors of arabica beans when they think of coffee. However, there’s another species of coffee that deserves more respect — robusta (Coffea robusta).

Often considered inferior to its close relative arabica, robusta coffee is more or less ignored in the West — but why? 

Coffea robusta is extremely popular in Asian countries — it has earthy, nutty, and chocolatey tones and a pronounced yet pleasant bitter edge. Robusta beans brew a remarkable cup of coffee, and the robusta plant itself holds the promise of a sustainable future for coffee production. 

In this article, we delve into the world of Coffea robusta, exploring its characteristics, history, cultivation, and why you might be helping the environment by switching up your morning brew.

What is Coffea robusta?

Coffea robusta is a flowering shrub in the “coffee” family. This “species” is technically a variant of Coffea canephora, but it’s (unofficially) recognized as its own species because it’s the most commonly cultivated variety. It coined the name “robusta” due to its “robust” nature and ability to fight off disease and pests.

Coffea robusta grows one of the most popular coffee beans in the world. It’s one of the two main species of coffee commercially cultivated for consumption, the other being Coffea arabica (arabica coffee).

Robusta coffee makes up around 40% of global coffee production — Coffea arabica is the dominant cultivar, representing around 60% of the world’s coffee production. Coffea robusta originates from Central and Western Africa but is cultivated commercially in Asia, South and Central America, and parts of its homeland Africa. 

Compared to arabica, robusta is a fairly young coffee. Although the Coffea canephora species has existed for millions of years, it was first discovered and used to make coffee in the late 19th century. In the wild, Coffea robusta plants can grow to heights of 10 meters (32 feet). However, they’re pruned to a more manageable height in cultivation. 

Robusta coffee is known for its strong, bold flavor with earthy, woody, and often bitter notes. The beans contain around twice as much caffeine as arabica — producing 68.6 to 81.6 grams of caffeine per kilogram. 

Taxonomy & Anatomy

Coffea robusta (C. canephora) is a flowering shrub native to Central and Western Africa. It belongs to the family Rubiaceae and is the second most dominant cultivar in coffee production. 

The discovery and formal classification of Coffea canephora is often attributed to the Belgian botanist Émile Laurent and his colleagues. Laurent identified and documented the species during the late 19th century during one of his expeditions to Central Africa. He published a formal botanical description of C. canephora in 1895. 

With that said, it’s unknown who first “discovered” the species and began commercially cultivating it as a crop. 

Taxonomy

• Kingdom: Plantae
• Division: Magnoliophyta
• Class: Magnoliopsida
• Order: Rubiales
• Family: Rubiaceae
• Genus: Coffea
• Species: Canephora
• Variant: Coffea canephora var. Robusta

Anatomy

In the wild, Coffea robusta plants grow to 25 to 32 feet (8 to 10 meters). They have woody stems and open branches with dark green, waxy leaves that grow in pairs on either side of the branch. The leaves are generally much larger and broader than those of Coffea arabica. They’re elliptical to oblong in shape and grow to around 16 inches (40 centimeters) in length. 

Coffea robusta plants are pruned to manageable heights of 6 to 13 feet (1.8 to 4 meters) in cultivation. This improves production and makes harvesting the seed-bearing fruits easier.

Coffea robusta flowers are white and fragrant, similar to those of Coffea arabica. They grow in clusters at the nodes of each branch. 

The flowers are hermaphroditic, meaning they harbor both male and female reproductive organs (stamen and pistil). Although they can technically self-pollinate, the presence of pollinators such as bees vastly improves the quality and the size of the beans produced.

The fruits of Coffea robusta (often known as coffee cherries) are drupes — fleshy fruits with a stony "pit" in the center that encases one or two seeds. Unripe fruits start green and gradually turn purple-red when ripe. Each robusta fruit contains two coffee seeds, which we know as "coffee beans."

The seeds (coffee beans) of Coffea robusta are typically smaller, rounder, and have a more irregular shape compared to arabica beans. Each bean has a straight crease line down the center. Fresh seeds are green to pale yellow or cream. They adopt the dark brown shades associated with coffee when they’re roasted. 

The Taste of Robusta Coffee

Robusta gets a bad rap in the coffee scene. It's often shunned as arabica's inferior sibling because of its bitterness and less complex flavor profile. However, it doesn't deserve this reputation. When prepared correctly, Coffea robusta beans make a fantastic cup of coffee, offering a unique and bold taste experience that can be appreciated in its own right.

The quality of the robusta beans, how it has been roasted, and how you brew it all affect the taste experience of the resulting cup of coffee. 

Not everyone will enjoy robusta, even if the quality and brewing method is pristine. Some people simply don't like the lack of sweetness and the woody, bitter profile of robusta, but this can be minimized by adding sugar and/or cream.

Related: What Does Vietnamese Coffee Taste Like?

Flavor Notes

• Earthy: Strong earthy flavors reminiscent of wood, soil, and bark.
• Nutty: Bold nutty flavors such as walnut, pecan, and hazelnut.
• Woody: Aromas of pine and cedar and robust woody notes.
• Bitter: Pronounced bitterness and lack of sweetness.
• Chocolate/Cocoa: Deep, rich undertones of cocoa beans or dark chocolate.
• Spices: Subtle spicy notes similar to pepper, cloves, and anise. 
• Herbs: Notes of woody herbs such as thyme, rosemary, and sage. 

Caffeine Content

The caffeine content in Coffea robusta is much higher than beans from other species. Robusta coffee contains around twice the amount of caffeine as arabica coffee. 

Coffea robusta contains 68.6 to 81.6 grams of caffeine per kilogram of unroasted, dried ground beans [1]. Compared to Coffea arabica which produces 34.1 to 38.5 grams of caffeine per kilogram, that’s pretty strong. It’s this high caffeine content that’s partly responsible for the bitter notes associated with this coffee bean. 

Sugar Content

The sucrose content in different species of coffee plays a huge role in taste. Arabica coffee has a relatively high sucrose content (6.25% to 8.45%), which is what gives the coffee its sweet, syrupy flavor. 

Coffea robusta produces low sucrose levels of 0.9% to 4.85% [2]. This affects the taste quite substantially, contributing to bitterness and a more straightforward, earthy, woody flavor. 

The History of Coffea robusta

Coffea robusta (C. canephora) is native to the humid forests in Central and Western Africa. It’s naturally distributed throughout the Democratic Republic of the Congo, Uganda, Angola, Gabon, Cameroon, Guinea, Liberia, Sierra Leone, South Sudan, and the Ivory Coast (Côte d'Ivoire). 

The seeds of the Coffea robusta plant have likely been consumed for millennia by the native people of Central and West Africa, although they likely chewed the seeds rather than turning them into a beverage. It’s unknown who exactly discovered the plant and when the first cup of coffee was made from its seeds. 

The Rapid Rise of Robusta Coffee Production

Unlike Coffea arabica, which has a well-documented history dating back centuries, Coffea robusta was identified relatively recently. 

It was supposedly “discovered” at some point during the 19th century and scientifically described by the Belgian botanist Émile Laurent in 1895. Laurent recognized its unique characteristics and potential for cultivation. However, conflicting sources make it difficult to determine who exactly introduced robusta to the Western world. 

It’s believed that the cultivation of the species began in 1870 in Congo — now recognized as the Democratic Republic of the Congo (DRC). The first seeds to make it back to the West were likely collected from one of these early plantations. 

The Belgian Congo (a Belgian colony that ruled the Congo from 1908 until 1960) became the principal breeding center for this species in the early 20th century. Robusta seeds were sent from here to Brussels and then introduced to several tropical countries across the globe.

The adoption of robusta came during a time when a major outbreak of coffee leaf rust (Hemileia vastatrix) was devastating Coffea arabica plantations in Southeast Asia. To combat the devastation caused by the disease, European colonists and agricultural experts introduced Coffea robusta to Southeast Asia. Robusta's natural resistance to leaf rust made it an ideal candidate to replace the decimated arabica crops.

Throughout the 20th century, robusta spread across the globe. Plantations appeared across Asia and South America, and cultivation expanded in Central and West Africa. 

Vietnam's Emergence as a Coffee Powerhouse

After the Vietnam War, the Vietnamese government sought to rebuild its economy and identified coffee as a key avenue for economic growth. During the late 1970s and early 1980s, Vietnam initiated a major coffee production program, focusing on Coffea robusta due to its resistance and high yield potential.

The “Doi Moi” economic reforms in the mid-80s further accelerated the Vietnamese coffee industry. These reforms opened up international trade and encouraged local producers to grow coffee for export. During this time, international organizations and foreign governments provided funding and expertise to help develop Vietnam's coffee sector.

The combination of government support, international investment, and a favorable environment for robusta coffee production led to a rapid expansion of Coffea robusta cultivation in Vietnam. By the 1990s, Vietnam had become one of the world's largest producers of robusta coffee.

Fast forward to today, Vietnam is a superpower in the coffee industry alongside countries like Brazil and Colombia. Vietnam is now the biggest exporter of robusta coffee in the world. The country continues to develop its coffee farming practices and processing techniques to improve the quality of its beans, address environmental concerns, and ensure the long-term viability of its booming coffee industry. 

Related: Types of Vietnamese Coffee

Cultivation & Distribution

Coffea robusta isn’t fussy in terms of growing conditions. This plant grows at lower altitudes, doesn’t need consistent rainfall, can cope with temperature fluctuations, and is much more resistant to disease and pests. This makes it more sustainable than Coffea arabica.

Cultivation Requirements of Coffea robusta

Coffea robusta tolerates warmer climates and can grow at temperatures between 15°C and 30°C (59°F to 86°F). Although larger yields and higher-quality beans are produced in more stable climates, robusta can handle significant temperature fluctuations.

Unlike arabica coffee, Coffea robusta grows at lower altitudes, typically from sea level up to around 2600 feet (800 meters). These plants do not require consistent rainfall, and while they still require some water for growth and fruit development, robusta plants are more resilient to drought conditions than arabica plants.

This species prefers loamy (fertile with a mixture of sand and clay), well-drained soil with a slight acidity. The optimal pH range for robusta coffee cultivation is typically between 5.5 and 6.5. 

Coffea robusta plants are impressively resilient to disease and pests. This is likely due to the high caffeine levels in the leaves and fruits of the shrub. Controlling pests and invasive fungi may be required but the resilience of Coffea robusta reduces the need for chemical interventions. 

This species flowers irregularly. After pollination, the berries take 10 to 11 months to fully ripen, meaning harvesting occurs almost year-round. 

Distribution of Coffea robusta

Coffea robusta is grown in Asia, Africa, and South America. Robusta coffee accounts for around 40% of the world’s coffee production and is the second most dominant cultivar after Coffea arabica. Vietnam is the leading producer of robusta coffee, which makes up 90% of the coffee grown there.

Vietnamese robusta coffee is known for its strong, earthy flavor with notes of oak wood, nuts, and caramel. It’s more bitter than arabica coffee due to the high caffeine content and has a more pungent aroma — often described as burned rubber. 

Coffea robusta is also grown in Thailand, Indonesia, India, and the Philippines. Asian varieties tend to have a more pronounced bitterness and a medium to full body with woody and nutty notes. 

Robusta coffee is also produced in Africa, with Uganda and Côte d'Ivoire as the largest producers. African robusta often exhibits bold and earthy flavors with nutty notes and a full body with a rich mouthfeel. 

Coffea robusta is also produced in South America, although cultivation of arabica coffee is much more common. Robusta coffee from South American regions such as Brazil and Colombia often produces chocolatey and nutty flavors with subtle fruity undertones. This is likely due to cultivation at higher altitudes. 

Why Robusta Coffee is a More Sustainable Choice

Robusta coffee is considered more sustainable than Arabica coffee for several reasons. Coffea robusta is much less environmentally demanding compared to Coffea arabica. The plants require less water, less specific growing conditions, can cope with external stress factors, and produce more coffee beans per acre of land. 

Here’s why robusta may be the future of sustainable coffee production:

1. Environmental Adaptability

Coffea robusta is much more adaptable to a range of environmental conditions. With a changing climate, this provides security for a future with coffee in it. 

Coffea arabica is notoriously “picky” about its growing conditions. It must be grown at the correct altitude in a stable climate with adequate rainfall. Robusta plants aren’t as fussy in terms of environmental conditions and can grow at much lower altitudes. This means plantations can be established in a wider area across the globe, reducing transport costs and environmental impact. 

The adaptable nature of Coffea robusta makes it much less resource-intensive compared to C. arabica. Not only is this better for the environment, but it reduces production costs significantly. 

2. Lower Water Requirements

Coffea robusta plants require significantly less water compared to Coffea arabica plants. This reduced water demand makes robusta cultivation more sustainable, especially in regions prone to water scarcity and drought.

With global water scarcity becoming an increasingly pressing issue, the lower water requirements of Coffea robusta make it a more sustainable option for coffee cultivation in the future. 

3. Resilience to Pests and Diseases

Coffea robusta plants have natural defenses against pests and diseases. They’ve adapted to grow in richly biodiverse environments, meaning they’ve evolved to naturally repel insects and fight disease. The higher caffeine content in the leaves and fruits of robusta acts as a built-in insecticide and fungicide [3].

This natural resilience reduces the need for chemical pesticides and fungicides and promotes healthier ecosystems in coffee-growing regions. It also makes for a healthier result for us consumers — a cleaner cup of coffee with fewer chemicals. 

4. Higher Yield Per Acre

Coffea robusta generally produces more beans per acre compared to Coffea arabica plants. This higher yield potential means less land is needed to produce the same amount of coffee, reducing the deforestation, habitat loss, and soil degradation associated with the ever-growing coffee industry. 

Benefits of Consuming Robusta Coffee

Robusta coffee hosts a range of benefits. Consuming it in moderation may improve cognitive function and metabolic health, and it may even help the environment. 

Here are some of the potential benefits of robusta coffee:

1. Improves Cognitive Function

The caffeine in robusta coffee may enhance cognitive function. Drinking coffee in moderation could help improve focus, increase energy levels, and even reduce the rate of cognitive decline, as some studies suggest [4]. 

Additionally, robusta coffee contains chlorogenic acids, antioxidants that have been linked to improved cognitive function and brain health [5]. These compounds may help protect the brain against age-related cognitive decline and neurodegenerative diseases such as Alzheimer's disease. 

2. Supports Metabolic Health

Studies suggest that caffeine in coffee can improve metabolic health by speeding up metabolism and promoting lipid oxidation. This could improve personal health dramatically by decreasing liver damage, reducing inflammation in the body, and aiding in weight loss and management [6]. 

The high caffeine levels in robusta coffee make it a promising candidate for supporting metabolic health, even more so than other types of coffee. 

3. Eliminates Free Radicals in the Body

Coffee made from Coffea robusta beans is rich in antioxidants, including chlorogenic acids and polyphenols. These compounds help eliminate free radicals in the human body.

Free radicals are unstable molecules that cause oxidative damage to cells, leading to inflammation, the “aging effect,” and various chronic diseases. By neutralizing free radicals, the antioxidants in robusta coffee help protect cells from oxidative stress and reduce the risk of oxidative damage [7]. 

4. Less Impactful on the Environment

Although not a direct benefit to personal health and wellness, robusta coffee production is much less straining on the environment compared to arabica coffee production. 

It's in everyone's interest to preserve the world for the future, and switching from an arabica to a robusta blend could help slow down deforestation and soil degradation, reduce water usage, and eliminate chemical runoff and eutrophication.

The Best Ways to Consume Coffea robusta 

Coffea robusta beans can be prepared and consumed in several different ways. To get the best experience from robusta, it's important to learn how to brew it, more so than arabica. In our opinion, the best way to enjoy robusta is to use a Vietnamese bean and brewing technique.

Let’s take a look at four different ways to prepare robusta coffee for the best experience:

1. Vietnamese Coffee (Using a Phin Drip Filter)

Vietnamese coffee is prepared using a traditional brewing device known as a phin drip filter. Robusta coffee beans are finely ground to the consistency of sand. The ground coffee is placed in the phin filter’s chamber, which sits on top of a heat-resistant glass cup. A gravity press is then used to distribute the grounds evenly. 

A small amount of hot water is added to the coffee to make it bloom. After 45 seconds, the chamber is filled just below the brim with more hot water. The lid is then placed on top. It takes around 2 minutes for the first drips to appear, and then five minutes after this for the brewing process to complete.

After a total of 7 minutes, the filter is removed and sweetened condensed milk is added. Although it's traditional to add condensed milk, this brew can be consumed black or with milk, cream, and/or sugar. 

2. Vietnamese Iced Coffee (Cà Phê Sữa Đá)

Cà phê sữa đá, or Vietnamese iced coffee, is a refreshing and indulgent beverage made by combining strong brewed coffee with sweetened condensed milk and ice.

The basic process is the same as making Vietnamese coffee with a phin filter. However, once brewed, the coffee is combined with ice and condensed milk.

3. Cold Brewed Robusta Coffee

Cold-brewed robusta coffee is made by steeping coarsely ground coffee beans in cold water for an extended period, typically 12-24 hours. This slow brewing process results in a smooth and mellow coffee with lower acidity and bitterness compared to hot brewing methods.

The process is simple but takes a while to brew. The basic process involves grinding whole-bean coffee using the coarse setting, steeping the coffee in cool water, and refrigerating overnight. It’s then strained the following day. Condensed milk, cream, or coconut milk can be added to make the beverage sweeter and creamier.

Learn how to make cold brewed robusta coffee: How To Make Vietnamese Cold Brew Coffee (Plus 5 Delicious Recipes)

4. Robusta-Infused Edibles

Coffea robusta beans aren’t limited to drinks. 

The deep, earthy, nutty flavors of robusta coffee combine well with a range of edible treats. This bean works particularly well in chocolatey desserts such as brownies, mousses, and ice creams. 

Robusta chocolate bars and gummies are also growing in popularity. Gummies, in particular, provide an exciting and convenient new way to experience the flavors and effects of this underrated coffee bean. 

FAQs: Coffea robusta & Other Coffee Species

Want to learn more about Coffea robusta and other coffee-producing species?

Have a read through the answers to some of the questions we’ve received below. If you don’t find what you’re looking for, feel free to check out the Cafely blog or contact us. 

1. What's the Difference Between Robusta & Arabica Coffee?

Robusta coffee and arabica coffee come from two different coffee-producing plant species — Coffea canephora (commonly known as Coffea robusta) and Coffea arabica. 

Despite belonging to the same genus (Coffea), robusta and arabica coffee have distinct differences in flavor, aroma, and caffeine content. They also have different cultivation requirements and originate from different regions.

Robusta Coffee 

Robusta is characterized by its strong, bitter flavor with earthy, woody, and nutty notes. It has a more pungent yet less complex aroma compared to arabica coffee and the beans have a lower acidity, resulting in a less tangy, fruity flavor profile. Robusta coffee is popular in eastern countries, especially countries such as Vietnam and Thailand.

Coffea robusta coffee beans are much smaller, rounder, and less uniform in shape compared to Coffea arabica beans. They have a straighter central crease line and contain significantly more caffeine — double that of arabica beans.

The Coffea robusta shrub is much more adaptable to environmental changes. They grow at lower altitudes (up to 2600 feet) and are more resilient to temperature change, irregular rainfall, pests, and adverse weather conditions. This makes them easier and less resource-demanding to cultivate. 

Arabica coffee 

Arabica coffee is characterized by its smooth, mild flavor with a wide range of subtle notes, including fruity, floral, and nutty. It has a complex, delicate, and aromatic fragrance, often described as sweet and chocolatey. The beans have a higher acidity compared to robusta, giving the coffee a bright, vibrant, floral flavor profile. Arabica is the favorite bean among Western coffee drinkers. 

The arabica beans are larger, more uniform, and more elongated than robusta beans. They contain less caffeine — around half of what's found in robusta beans. 

Coffea arabica plants thrive at higher altitudes, typically between 2000 and 6500 feet above sea level. They require consistent temperatures and regular rainfall and are much more prone to disease and pests, making cultivation a demanding process. 

2. What Type of Bean is Used in Instant Coffee?

Arabica, robusta, or a blend of both coffee beans can be used to make instant coffee. However, robusta beans are more commonly used in instant coffee due to their stronger flavor, and higher caffeine content.

Robusta beans are much cheaper than arabica beans. Most arabica gets turned into "premium" whole bean or ground coffee. It's more cost-effective to use robusta beans in large-scale instant coffee production, and as you can probably imagine, the best robusta beans aren't turned into instant coffee. 

The process of making instant coffee involves brewing large quantities of coffee, which is then strained and dehydrated to create soluble granules or powder. This process masks some of the flavors of high-quality beans, which can be considered a waste. Most manufacturers of instant coffee will use the cheapest, lowest-grade robusta beans possible.

After all, instant coffee is marketed as a convenient and economical option for a quick brew rather than a premium product. However, Cafely takes all coffee seriously, even instant. Check out our selection of premium instant coffee and be prepared to be amazed.

3. Is Coffee a Drug?

Yes, coffee can be considered a drug due to its caffeine content.

Caffeine is a central nervous system stimulant that temporarily reduces drowsiness and increases energy. This technically makes it a psychoactive substance — the most widely consumed psychoactive substance in the world.

The caffeine in coffee can increase heart rate, increase blood pressure, and stimulate the release of certain neurotransmitters such as dopamine and norepinephrine. Regular consumption of caffeine can lead to addiction and physical dependence. Over time, people can develop a tolerance to coffee, meaning they may need to consume more to achieve the same effects.

Coffee is a drug and should be treated with respect like any psychoactive substance. Moderate coffee consumption can improve mental alertness, concentration, and physical performance but excessive. However, long-term caffeine use can lead to some negative effects, such as insomnia, anxiety, digestive issues, and increased heart rate. 

Learn more: What is Caffeine Withdrawal?

References

1. Jeszka-Skowron, M., Sentkowska, A., Pyrzyńska, K., & De Peña, M. P. (2016). Chlorogenic acids, caffeine content and antioxidant properties of green coffee extracts: influence of green coffee bean preparation. European Food Research and Technology, 242, 1403-1409.
2. Caporaso, N., Whitworth, M. B., Grebby, S., & Fisk, I. D. (2018). Non-destructive analysis of sucrose, caffeine, and trigonelline on single green coffee beans by hyperspectral imaging. Food Research International, 106, 193-203.
3. AlEraky, D. M., Abuohashish, H. M., Gad, M. M., Alshuyukh, M. H., Bugshan, A. S., Almulhim, K. S., & Mahmoud, M. M. (2022). The antifungal and antibiofilm activities of caffeine against Candida albicans on polymethyl methacrylate denture base material. Biomedicines, 10(9), 2078.
4. Kim, H., Kang, S. H., Kim, S. H., Kim, S. H., Hwang, J., Kim, J. G., ... & Kim, J. B. (2021). Drinking coffee enhances neurocognitive function by reorganizing brain functional connectivity. Scientific reports, 11(1), 14381.
5. Ochiai, R., Saitou, K., Suzukamo, C., Osaki, N., & Asada, T. (2019). Effect of chlorogenic acids on cognitive function in mild cognitive impairment: A randomized controlled crossover trial. Journal of Alzheimer's Disease, 72(4), 1209-1216.
6. Corbi-Cobo-Losey, M. J., Martinez-Gonzalez, M. Á., Gribble, A. K., Fernandez-Montero, A., Navarro, A. M., Domínguez, L. J., ... & Toledo, E. (2023). Coffee Consumption and the Risk of Metabolic Syndrome in the ‘Seguimiento Universidad de Navarra’Project. Antioxidants, 12(3), 686.
7. Lobo, V., Patil, A., Phatak, A., & Chandra, N. (2010). Free radicals, antioxidants, and functional foods: Impact on human health. Pharmacognosy reviews, 4(8), 118.