Out of the four major types of coffee beans on the market, robusta beans are affordable, have more caffeine than some other breeds, and are widely grown around the world. You might expect a coffee chain like Starbucks to use the cheap and easy-to-find robusta as its default coffee option, but they actually use a different type.

Starbucks uses high-quality arabica beans in all their coffee drinks, since they believe arabica coffee has a more dynamic flavor. Engagement manager Aaron Robinson says that "It can be elegant. It can be complex. It can have body and acidity that is interesting and can be used and played with and blended into new, interesting tastes."

The high elevations at which arabica trees grow allows the coffee fruits mature at a slower rate and their develop flavor, resulting in this complexity. This also makes them fruitier compared to the more bitter robusta beans, and the versatility of arabica is important, considering the many wildly different coffee drinks that Starbucks offers.