Coffee isn't taken from a single species of coffee plant. Hundreds of varieties of coffee species are planted around the world. The two main core species which mark the distinction between speciality and commodity coffee are as follows. Variations of arabica are planted for speciality coffee, and Robusta are planted for commodity. For coffee enthusiasts oriented on quality, we are primarily concerned with the world of C. Arabica or simply 'Arabica'.
Source: Counter Culture Coffee - https://counterculturecoffee.com/blog/coffee-basics-coffee-varieties-what-kinds-of-coffee-varieties-are-there
Varieties of Arabica occur from natural cross genetic mutations in the wild, or are genetically engineered from human intervention. The original variety which kickstarted the global coffee revolution was Typica. In the early 18th century the Dutch spread Typica, a variety from Ethiopia, around the world. Typica contains the vibrant red colour most people associate with coffee cherries, and is still grown to this day given its capability of excellent cup quality.
A hallmark of transparency, and coffee quality is including the coffee variety on the bag of coffee. This demonstrates the care and attention to detail the farmers and roasters notice with different varieties, and provides an extra layer of education about what the coffee farmer prioritises.
Factors such as cost, yield, resistance to disease, sought after characteristics all play a role in a coffee farmers decision of which variety to plant. Sometimes the best coffee varieties for flavour are too risky for a farmer who's top priority is making ends meet from a secure and reliable crop which yields well.
Below are some examples of popular coffee varieties which have desirable growing and flavour characteristics :
Bourbon - From the island of Reunion, the yield is higher than Typica, and contains a particular sweetness which many in the coffee industry find desirable. This variety even comes in the colours yellow and orange.
Mundo Novo - This variety is usually grown for its high yield, strength and resistance to disease.
SL-28 - A prized man-made genetically modified coffee variation. SL-28 was created by Scott laboratories, Kenya, in 1928. This variety is desirable given its capacity for producing a cup with a blackcurrent fruit flavour.
Geisha - This highly sought after variety gained prominence in 2004, after the Panamanian farm, Hacienda La Esmeralda put forth Geisha into a competition, and won over the crowd, resulting in a remarkably high bid of $21/lb at auction. Geisha contains such complex layers of fruity tasting notes, and truly a delight to taste.
It's also worth noting that coffee varieties tend to adopt characterstics of the terroir in which they are grown, ultimately affecting flavour, so a Geisha grown in two different parts of the world may have different flavour profiles. This just scratches the surface into the complex world of coffee varieties, so we hope this introduction clears any misconceptions, and sheds light on the importance of identifying and appreciating this crucial aspect to coffee quality.