Just like wine grapes, coffee beans can come from a big range of regions that have the right climate. Where they’re grown affects flavor, caffeine levels, and mouthfeel, so not all beans are created equal.
There’s an entire world of coffee bean geekery out there, with different regions creating slightly different flavor profiles that can be broken down into body, acidity, and flavor. Unless you’re an obsessive connoisseur, though, all you really need to know is the difference between two overarching bean varieties: Arabica and Robusta.
They’re tougher to grow since the plants are susceptible to pests, need careful attention while growing, and require an altitude of 600m or higher. Still, they make up 70% of the world production and at least partially make up most coffee blends that you’ll find at any store or café.
Arabica beans come in a wide range of flavors, but generally, they’ve got a soft, sugary, fruit-y sweetness and high acidity. And while those flavors are tasty and make for a great cup of coffee, not all Arabica beans are high quality.
Most are, and the best coffees around are made from Arabica beans, but it’s not always a guaranteed indicator of quality.
Since they don’t need a high altitude to grow, these are produced across a bigger swath of the globe. They’re also more resistant to pests and weather, pack much more caffeine, require less maintenance, and grow more quickly with more beans per tree.
Even despite all of that, Robusta beans are a minority of the global coffee output. That's because they’ve got a harsher flavor that doesn’t yield nearly as good a cup of coffee as Arabica beans, and they’re usually used as a cheap filler to part-Arabica blends in instant or pre-ground coffee.
They’re not all terrible, just like all Arabica isn’t great, but in general you should avoid the stuff whenever possible.