One of the things we all love about coffee is how complex it is: A seemingly endless number of flavors, aromas, textures, and even physical characteristics that coffee can have. At the same time, it’s fascinating to think of how similar most of the world’s coffee beans are, at least genetically speaking.
In this post, we’re going to take a closer look at what it means for a coffee plant to be classified as part of the species known as Coffea arabica.
What Is “Arabica” Coffee?
When we think of “specialty coffee,” Arabica coffee is what we imagine: From farm to cup, the Arabica bean comes from the most delicate, diverse, and dynamic coffee plant grown worldwide. Successful coffee production requires specific climate conditions, more labor, and consistent care to grow; it’s given way to hundreds of distinct varieties and cultivars; and it’s capable of expressing an enormous range of flavors, from chocolate and nuts to fruit, florals, herbs, spices, and more.
As of this writing, there are more than 120 recognized species within the genus Coffea recognized around the world, according to research headed by Dr. Aaron Davis at the Royal Botanic Gardens, Kew.1 Of those species, however, only two are considered commercially viable: Coffea canephora or Coffea robusta, which you may have heard be referred to as Robusta coffee, and Coffea arabica, or Arabica coffee. Around 70 percent of the world’s coffee production is Arabica species. It grows best at higher elevations (900-ish meters above sea level and higher) and tends to be somewhat picky about soil nutrition, climate patterns, pruning, and more.
It remains unclear where the Arabica coffee plant originated. However, Dr. Davis’s research has led to the plausible assumption that Coffea arabica is the result of “the hybrid union of two African coffee species: robusta coffee (Coffea canephora) and Nandi coffee (C. eugenoides), or perhaps from two other very closely related species (extant or extinct).”2 Coffee geneticists speculate this likely happened in the area now identified as Ethiopia, or the area surrounding the contemporary border between Ethiopia and South Sudan: They’ve deduced this from the amount of distinct genetic diversity that exists among Arabica coffee found in these origins, which is unique to anywhere else on the planet. It was then transplanted to Yemen, where it was first commercialized: The reason it’s called Coffea arabica rather than Coffea ethiopia is related to the transformation it underwent thanks to Yemeni agriculture (and is still a very contested point about the taxonomy of the species.)
While other species within the Coffea genus contain 22 chromosomes, Arabica coffee has 44. It also has a much lower caffeine content than the Robusta bean, which is only one of few differentiators between Arabica vs. Robusta.
One study shows that green Coffea arabica has a caffeine content of roughly 0.8–1.9 percent (of dry weight), while Canephora may comprise between 1.2–2.4 percent caffeine (dry weight).3-4 (The roasting process appears to reduce coffee’s caffeine content by as much as 30 percent across species, though your mileage may vary based on roasting style and method, age of the coffee beans, and other factors.)
Varieties of Arabica
To understand the varieties of Arabica coffee, it’s helpful to think about another common plant with a wide variety of distinct flavors, textures, and physical characteristics, just like coffee: apples. Granny Smith, Red Delicious, Gala, Braeburn, MacIntosh—they all belong to the same species but are genetically different enough to express a wide range of tasty personalities.
There are countless varieties and cultivars within the Arabica plant species, though they all share the same Arabica roots. Genetics are one of the many variables that impact coffee taste and quality. While they can be predictive, they’re not a perfect indicator of a cup or score. In addition to the pedigree of the coffee itself, external factors such as terroir, ripeness of the pick, post-harvest processing, drying, storage, and naturally roasting and brewing will have considerable influence over a coffee’s flavor profile.
“Variety” is the term used to describe a strain of plant family that is naturally occurring, created by natural cross-breeding or mutation rather than human interference; compare that with “cultivars,” which are either selected or intentionally cross-bred to capitalize on beneficial characteristics, like productivity, drought resistance, or dwarf stature.
Within Ethiopia, there are many distinct “landrace,” or wild varieties of Arabica beans, which grow in forest conditions. There are also called “heirloom varieties,” a somewhat misleading term generally used to describe an extensive catalog of coffees native to Ethiopia and haven’t been planted in other coffee-growing countries. (It’s tricky because it’s often applied to Ethiopian coffees at will, though many of the coffee types grown in Ethiopia today are cultivars, selections, and more modern hybrids.)
Generally speaking, however, Ethiopian Arabica coffee is distinct from that in other growing countries: When processed as a Washed coffee, many Arabica varieties have delicate floral, tea-like, lemongrass, honey, stone fruit, or citrus notes.
Two of the other most prominent varieties of Arabica coffee are Bourbon and Typica. Typica is the genetic result of a coffee tree being stolen from Ethiopia and planted in Yemen, mutating to adapt to its climate, and then having its clippings stolen and planted on the Indonesian island of Java, where it is mutated again to survive. Clippings from a Javanese Typica plant were eventually presented as a gift to the king of France. The plant he kept in his greenhouse is considered the source of most of the coffee planted throughout the Americas in the 18th century. (That gifted plant is known as the Noble Tree.) Genetically pure Typica is somewhat challenging to find, though it is grown in Ecuador, Perú, and Mexico, among other places in Latin America. It’s long been thought to have a chocolate-forward profile with some deep red fruit notes, like ripe cherry, and an almond-like nuttiness.
Bourbon variety started the same way as Typica: being selected from a farm in Yemen. However, rather than being planted on Java, it was taken to Île Bourbon (now called Reúnion) in the 18th century and mutated to adapt to its new surroundings. The Bourbon variety is still commonly grown, especially prominent in El Salvador, Rwanda, and Burundi. Bourbon is known for its sweet and balanced profile, with butterscotch, caramel, almond, cashew, and chocolate being commonly found notes.
How to Get the Best Out of Your Arabica Coffee
Since you’re buying coffee from Trade, it’s fair to say that you’re drinking Arabica coffee: It’s long been considered the better-tasting, more delicate, and nuanced type of coffee grown around the world, and is prized by roasters and coffee lovers alike for that reason.
Due to its dynamic profile, Arabica coffee is best prepared fresh. Buying Arabica beans “in-season” is like buying strawberries in-season: They simply taste better. (Note that the growing and harvesting season of coffee is not necessarily the time it’s best to drink them: Due to the necessary processing, drying, storing, and shipping, green coffee might not be available to a roaster for three to six months after being picked.)
As you learn how to make coffee using Arabica beans, it’s important to keep in mind that grinding fresh is also a great way to boost your Arabica’s flavor quickly. You want to capture all the goodness in your cup, rather than let it dissipate into the air, and grinding right before brewing — rather than pre-grinding and storing in a bag — will help you maximize those results.
Store your Arabica coffee beans more like fresh bread than dried beans — which is to say that while they look like non-perishable items, their flavor will drop off more noticeably over time. They like to be kept in a cool, dry place (not the refrigerator) and will perform better if you use them while they’re fresh.