Coffee beans guide: Which type of coffee bean is best?
Whether you’re a seasoned coffee lover or just dipping your toes into the world of java, you might find yourself wondering: what are the best coffee beans?
The coffee industry is huge — and the many variations in origin, bean type, roast profile and more can make it difficult to navigate. So, we’ve written this one-stop coffee beans guide to help you understand what makes each type of bean unique.
How many coffee varieties are there?
To the uninitiated, it might seem like there are millions of unique types of coffee — but that’s because there are so many different labels that are used to categorise your average bean. These include:
- Country of origin
- Roast type
- Flavour profile
- Caffeine content
In actual fact, there are only four main varieties of bean. These are Arabica, Robusta, Liberica and Excelsa.
Arabica is the most popular type of coffee on the planet — estimates put global production at around 60% of total coffee output.
Arabica beans are large and oval-shaped. They’re mainly grown across Latin America, especially in Brazil, thriving in high altitudes 500-2,500 above sea level.
While the tropical climes of Brazil provide ideal growing conditions, Arabica is particularly sensitive to environmental influences like disease and unsteady rainfall. This makes it a little more expensive to produce than other beans, and generally a little pricier to buy.
However, this hasn’t slowed the large global demand for Arabica. Its mild, delicate flavour profile is enjoyed by the masses, with complex floral notes and the occasional hint of chocolate. It tends to be sweeter and less acidic than other coffees and offers a lower caffeine content.
The second most popular coffee bean is Robusta, accounting for 30-40% of commercial production. Robusta also thrives in hot climates, but is a little tougher than its fair-weather sibling.
It can grow at altitudes under 1,000m even without regular rainfall, and is most commonly planted across Vietnam, Indonesia, and Africa.
The hardy Robusta bean is cheaper to produce than Arabica, and much less sweet. It’s sometimes criticised for its more bitter notes of burnt rubber and wood, and disregarded as a lower-quality crop. However, this isn’t always the case — high-quality Robusta is sought-after for its richer flavour and higher caffeine content, offering notes of rum and chocolate.
These bold beans are typically circular in shape and pale, with a less pronounced crease than Arabica.
One of the rarest varieties of coffee is Liberica. This coveted bean grows between 700 and 1,000m above sea level in Africa and Southeast Asia, especially across the Philippines and Malaysia. Its trees can reach up to 18m high and require special machinery to harvest from.
Liberica was a popular bean in the 19th century when leaf rust decimated Arabica production. Nowadays, there’s little global demand for Liberica — making it a scarce variety that accounts for just ~1% of global coffee. However, this does mean that the beans fetch a pretty penny when hard-to-come-by premium batches are sold.
Liberica beans are sought out by some aficionados for their unique flavours. The beans are said to have a woody or even metallic taste, with the occasional floral note. They’re lower in caffeine than both Arabica and Robusta, but much larger in size, with a distinctive asymmetrical shape where one side is longer than the other.
Last on our list is the Excelsa bean — but if we’re being technical, it’s actually a member of the Liberica family. Excelsa also grows predominantly in Southeast Asia, and at similar altitudes — but still maintains a unique character that coffee drinkers consider distinctive enough to be labelled differently.
Excelsa beans have a fruity body and a tart flavour that separates them from the more bitter-tasting notes of Liberica. As a result, Excelsa is often integrated into blends to provide a full body and complex flavour profile. It has lower caffeine content than both Arabica and Robusta.
This particular bean makes up around 7% of the coffee in circulation — and thanks to its scarcity, can sometimes be sold for high prices. It grows as a small, round bean that can be easily distinguished from the larger, almond-like shape of Liberica.
Where do decaf coffee beans come from?
It’s become something of an urban myth that coffee farmers can grow decaffeinated beans — in reality, all coffee beans naturally contain some caffeine content, even if the amount does vary.
To produce decaf coffee, unroasted green beans have their caffeine extracted. While decaffeination won’t remove every bit of caffeine from the bean, it does reduce it enough that you won’t be kept up by your evening brew. Nowadays, ‘half caff’ coffee is growing in popularity, made of a 50/50 blend of caffeinated and decaffeinated beans.
But how exactly are beans decaffeinated? These are the most common methods:
The Swiss Water method
Many of our decaf coffees are processed using the Swiss Water method. Here, a preliminary batch of beans is soaked to dissolve their caffeine and flavours into the water. The beans are then discarded and the water is passed through an active charcoal filter to pull out its caffeine molecules.
The next batch of beans can then be soaked in the decaffeinated solution to extract their caffeine without removing any flavour — because the water is already saturated with the flavour components from the previous batch. This way, coffee beans can be effectively decaffeinated without removing their all-important oils, leaving behind a flavoursome decaf bean.
The Carbon Dioxide method
The ‘CO2’ method is a new technique that forces liquid carbon dioxide into water-soaked green coffee beans at high pressure. This acts as a solvent which dissolves and draws the caffeine out from the beans without removing the larger flavour component molecules.
The caffeinated CO2 is then transferred to another container where it is de-pressurised and the caffeine is released — so the caffeine-free carbon dioxide can be reused for the next batch of beans.
The Indirect Solvent method
This process is common in Europe for commercial decaffeination. Here, coffee beans are soaked in hot water to extract caffeine and other flavour components, then the water is separated and transferred to another tank. A solvent such as methylene chloride or ethyl acetate is then added to the caffeinated water and selectively bonds with the caffeine molecules. The water can then be heated to remove the solvent and caffeine by evaporation.
Following this process, the beans can then be reintroduced to the water to reabsorb their flavour components.
The Direct Solvent method
Lastly, we have the Direct Solvent-based process. During this method, beans are steamed and rinsed with a solvent (usually ethyl acetate) to remove their caffeine. The high-caffeine solvent is then drained off of the beans, which are steamed once more to remove any residual solvent.
When a decaf coffee doesn’t say how it was decaffeinated, it’s usually one of these latter two solvent-based methods.
What are the best coffee beans?
Ultimately, what you consider to be the best kind of coffee will come down to personal preference — but Arabica coffee is generally considered to be superior. This mild, well-balanced bean tends to satisfy the tastes of the coffee drinker, so if you like your coffee black, Arabica could be the choice for you.
In fact, you’ll notice that Arabica coffee is typically graded for its quality, whereas Robusta is not. Grading systems around the world rate Arabica beans according to characteristics such as defects, processing type, roast appearance and cup quality. Robusta, on the other hand, has historically not been graded due to its unfavourable cupping quality. However, this perception of Robusta is changing as more drinkers come round to its merits in flavour and caffeine content.
If you drink coffee for a wake-up burst of energy, then you may prefer a high-caffeine Robusta. Many choose to balance its strong taste with milk or sugar to sweeten the deal.
Arabica and Robusta are the two main types of coffee bean, collectively accounting for over 90% of global production. As for Liberica and Excelsa, these varieties are harder to find — but their bold, berry-like flavours are growing popular with specialty coffee drinkers.
If you want to discover which type of coffee is best for you, why not give our coffee quiz a go? Tell us how you like your brew and we’ll match you to the perfect beans to be delivered straight to your door.