Alongside water and tea, coffee is one of the most consumed drinks in the world. It’s estimated that 2.25 billion cups of the stuff is enjoyed each day across the world, helping people to stay alert and maximize their potential.
We’re sure you’ve heard about arabica and robusta beans when on the hunt for your morning brew, but did you know they make up just two of the world’s four coffee plant varieties?
The other lesser-known coffee plants which fall under the Coffea genus of flowering plants in the Rubiaceae family are excelsa and liberica.
These rarer species can if cultivated and roasted correctly, produce just as good of a cuppa – so why are they always outshone by their more popular counterparts? In this article, we are going to delve deeper into the four coffee plant varieties and see what makes their beans so positively caffeinated and delicious.
What Is A Coffee Bean?
Before we dive into the coffee plant varietals and seeing as you’ll notice it popping up a lot in the article – we thought it would be helpful to ask the question; what exactly is a coffee bean? Against the namesake and popular opinion, coffee beans aren’t actually beans at all.
They are in fact the seeds that are located inside the fruit of the coffee plant.
This fruit has been termed the cherry (also not actually cherries) and because it is not commonly eaten, it is, therefore, a byproduct of coffee cultivation.
The fruit’s seed is taken out and roasted which is what brings on the flavors of the coffee and helps give it a bean-like appearance.
Arabica is the most widely grown, produced, and consumed coffee variety in the world. It’s estimated, of all the coffee that’s consumed in the world each day, 60% of it is Arabica.
The Coffea arabica plant is preferred for its high acidity which creates a complex and sweet flavor profile that is used in great effect to make all types of delicious coffee.
Arabica beans also have a noticeable lack of bitterness that makes for an irresistibly smooth cup of coffee too.
Originating in the Ethiopian highlands Arabica beans are quite possibly the first to have ever been consumed. Legend has it that around the year 850AD a goatherd by the name of Kaldi noticed his goats being unusually animated after munching on the ripe berries of a particular bush.
Inquisitive Kaldi then tried the berries for himself and felt just as energized. Some local monks caught wind of Kaldi’s discovery and it wasn’t long until news of this stimulating plant spread far and wide.
It wasn’t until the 12th century that Arabia (modern-day Yemen) started to cultivate the magical plant and, sure enough, it quickly popularised across much of the Middle East and soon after Europe.
Just as not all good things come easy, not all good coffee is grown easily too. Arabica is the hardest variety of coffee to grow, which, unsurprisingly, makes it the most expensive coffee to buy.
Just like the other coffee plant varieties, all of the world’s arabica is cultivated between the tropics of Capricorn and Cancer. However, arabica beans require additional shade, water, and a higher altitude of at least 2,000 ft to be grown successfully.
]Arabic plants are also more prone to disease. Another reason they are priced high is that Arabica doesn’t grow as big as the other varieties, meaning more plants need to be grown to produce the same amount of beans.
Robusta is the second most-consumed coffee variety, making up almost 40% of the world’s coffee.
Robusta is considered to have a higher caffeine level than arabica which also gives it a more potent, full-bodied taste. Robusta is also known for having a very strong scent and a slight burntness to its taste.
This bitterness is why Robusta is less preferred by specialty coffee roasters trying to achieve subtle tasting notes, and not just high caffeine levels.
Robusta is often blended with Arabica to give a good balance between cost, taste, and caffeine.
Although scientifically termed Coffea canephora, the world knows this hardy plant as Coffea robusta (hardy = robust). Robusta originated in the central and western sub-Saharan parts of Africa and was first discovered in the 1800s.
It is now widely grown in Southeast Asia, Brazil, Central America, and its homeland of Central and Western Africa.
Robusta is also widely consumed in these countries plus many other developing nations that enjoy their coffee strong and can’t afford the more specialist and expensive Arabica beans.
Because it is a hardy plant, Robusta can flourish in most parts of the Bean Belt (tropic of Cancer to Capricorn). It can grow to a staggering height of 20 ft, which gives it a much greater crop yield when compared to Arabica.
It’s also less susceptible to disease, which means it requires fewer herbicides and pesticides to prosper.
These reasons combined with the fact that it has just shy of double the caffeine of Arabica are why Robusta is produced and therefore sold for considerably less than Arabica.
Coffea liberica has a very small stake in the global consumption of coffee. At less than 2%, it is a very rare variety that is primarily grown in just a handful of Southeast Asian countries.
Rarely do people sit on the fence when it comes to the taste of liberica. Coffee lovers will either enjoy it for its peculiar flavor that features earthy and woody tones and a powerful finish.
Or, they will take one sip, compare it to dirty dishwater and never drink a cup of Liberica again. Liberica can also be wildly inconsistent in its taste, which doesn’t bode well with specialty coffee roasters who require dependable coffee for their customers.
Much like Robusta, Coffea liberica was first discovered in West Africa in the 1800s. It is native to Liberia, Uganda, and Angola but has since been naturalized in countries such as the Philippines, Indonesia, and Malaysia.
Liberica was first cultivated commercially in the Phillippines, where it is estimated that 70% of the world’s Liberica is produced (mostly for local consumption).
In the coffee rust pandemic of the 19th-century, liberica faired better than both arabica and robusta. However, even the large liberica coffee trees eventually lost out to the disease.
Which, subsequently, ravaged entire coffee plantations of the Philippines and left their industry reeling in the aftermath.
Unlike robusta and arabica which are considered to be bush or shrub, the size of Coffea liberica categorizes it as a tree. Often reaching 20 meters in height, liberica is the largest coffea plant variety by quite a substantial amount.
Their overall size also means that liberica beans are the biggest of the bunch too. Today liberica plants are considered endangered because of their low rates of cultivation on the world stage.
Liberica is rather scarce in most coffee markets of today and is often linked to a higher price point as a result.
If exported out of the Philippines and Malaysia and Indonesia where it is primarily grown, good quality liberica beans can fetch up to five times the price of robusta and arabica types.
In a slightly controversial decision, excelsa went from being its own classified coffee variety to a genus within the Liberica family.
However, many producers, roasters, and consumers within the coffee community still regard excelsa as its own species.
Due to very low production rates, excelsa is considered a mysterious bean that’s largely misunderstood.
This means it is mostly grown and roasted incorrectly and subsequently many people have a lower opinion of its quality than they should.
Good quality excelsa beans can offer a dark and fruity flavor that some coffee specialists seek out for its uniqueness.
Excelsa was discovered at the start of the 20th century in, you guessed it, Central Africa. Since its discovery, Excelsa has been widely cultivated in both Africa and Asia to great success.
However, in recent years it is primarily grown in the Southeast Asian countries of Vietnam and the Philippines. It was in 2006 that excelsa was re-classified as a subspecies of liberica.
This re-classification was mainly put down to the two plants having a very similar growing profile to one another.
Excelsa trees can grow up to 30ft and just like liberica, can be grown extremely well at medium altitudes of between 1000 and 1300 meters above sea level.
While the excelsa plant flowers multiple times in a single season, its fruit still requires a full year to mature (just like liberica).
]The leaves of an excelsa tree, grow, on average, 26 by 13 cm, which is a serious amount of foliage for its fruit to remain hidden in.
Although excelsa trees are productive and resilient, they still require a lot of attentive care and management when compared to the hardier, low-set shrubs of arabica and robusta.
This is partly the reason why excelsa is grown in such a low quantity and fetches a high price as a result.
As you can see, there is a lot to unpack when looking into the four (technically three) coffee plant varieties of the world.
This article aimed to put forward some of the more important points surrounding coffee plants to ensure that you know what you’re dealing with when sipping your next brew.
Hopefully inspiring some of the dedicated coffee crew to seek out the rarer beans of liberica and excelsa too.