There are hundreds of different species of coffee plant but only two which humans cultivate for the purpose of roasting, brewing and drinking: arabica and robusta.
And while both species can get along famously when they’re mingled in a coffee blend, there’s actually a whole host of differences between them. Everything from strength, flavour, quality and price to where and how they grow.
Here’s a quick guide to what sets them apart.
Pop a few arabica coffee beans on the scales and divide their weight by 70. That’s how much caffeine they contain – it’s around 1.5% of their weight (though that can vary quite a bit). Robusta coffee beans are little firecrackers by comparisons, containing almost twice as much caffeine.
This is the big one. Broadly speaking, arabica has a flavour which is softer, sweeter, more acidic and much more nuanced, while robusta is harsher and rougher. That’s not to say that robusta can’t be fantastic, though – seek out the good stuff and you can find a deep, smoky, powerful flavour profile that lots of people absolutely love.
Robusta might not always have as much going for it in terms of flavour, but there’s one thing it does deliver in spades – and that’s crop resilience. Robusta trees are less choosy and more hardy than arabica. They can grow at lower altitudes, they handle pests better and they’re more resistant to changes in the weather. They also need less time after planting to produce their first harvest, and they grow more beans too. In short, they’re a farmer’s dream.
The two factors above combine to create a gulf in price – generally speaking – between arabica and robusta. The sought-after flavour profiles and trickier growing conditions of arabica means it typically commands a higher price on the international market. It’s why you’ll often find robusta in cheaper coffees and instant coffees – though again, it bears repeating that robusta coffee isn’t necessarily bad, and arabica coffee isn’t automatically good.
Where it’s grown
About 40% of the world’s coffee is robusta and most is grown in Vietnam and Indonesia, where it’s the primary kind of coffee produced. India produces both robusta and arabica, as do lots of African countries and Brazil. Elsewhere in Central and South America, arabica is way more dominant, and Colombia doesn’t grow robusta at all.