Coffee is a lot like wine. Similarities include the importance of place of origin/terroir and the idea that the berries grown in the least nutrient-rich soil produce the most distinguished flavors. Another similarity between coffee and wine is general confusion regarding the meaning of many of the words used to label coffee on packaging and menus.
I drink coffee every day and am typically drawn to blends that are smooth and flavorful enough that I can enjoy a cup black. Despite my willing patronage and appreciation of a product that somehow tastes better, I realize that I lack any understanding as to what makes these high-end cups of coffee superior to something from the gas station convenience store. When ordering a pour-over at my neighborhood centers of coffee snobbery (I alternate between Thinking Cup and Barrington), I make a show of pretending to mentally debate between bean options whose labels make no sense to me. This exercise is total farce, as I have no idea what I'm doing when it comes to choosing a cup of coffee or a bag of beans that best fits my taste preferences and budget. When I turn to the packaging for guidance and help, potentially meaningless buzzwords abound, and I lack clarity on whether these labels are regulated and therefore factual (vs just marketing), and how they will affect flavor and price point. One of the most common words on labels is "Arabica", which I've dissected here. This is one of many terms commonly slapped onto coffee packaging that requires decoding to understand, so stay tuned for additional posts regarding coffee labels.
"100% Arabica" or "Arabica"
This label is ubiquitous in the world of coffee, perhaps because of how exotic it sounds. In reality, the meaning is fairly basic, indicating simply that the beans that the coffee is made of are from a certain species within the Coffea plant genus called Arabica. It also turns out that this label is largely unregulated.
To use another wine analogy, Arabica is to coffee as Vitis Vinifera is to grapes. There are varietals such as bourbon and typica within the Arabica species just like the Vitis Vinifera species has chardonnay and pinot noir. Like Vitis Vinifera vs other grape species, Arabica is widely associated with high quality vs product made with other coffee bean species. However, just like anyone who has every sampled a Charles Shaw White Zinfandel knows, a wine made with Vitis Vinifera grapes is not guaranteed high quality, just as a coffee made of 100% Arabica beans is not necessarily a quality product. However, the fact that the blend is made of 100% Arabica means that the potential for quality is high.
Arabica is the dominant species of Coffee, making up around 70% of production. Robusta, a less expensive, heartier species, makes up the remainder. As mentioned above, (almost*) all high quality coffee is Arabica, but not all Arabica coffee is high quality, so relying on the Arabica label alone will not do for the most discerning seekers of premium taste. In general, you will need to exercise caution to avoid buying a blend of both species if it is not your intention: if the label indicates Arabica but does not say "100% Arabica", the coffee likely contains some Robusta, which may contribute its characteristic flavors of burnt rubber and plastic (yuck!). Furthermore, I could not find any evidence that having "Arabica" on a label requires that the blend contain a minimum percentage of Arabica in it, so any blend labeled as such has the potential to be primarily Robusta. Look for the "100%" qualifier, but understand that even this label is also unregulated. Given coffee's status as a food that is exempt from food labeling and the fact that Arabica and Robusta are both still "coffee" at the end of the day, the labeling of coffee as "100% Arabica" or "Arabica" is up to the discretion of the producer. From what I can tell, the main incentive to be honest in this claim is a brand's desire to maintain ethical and consumer-friendly business practices and avoid any any bad publicity that would accompany a discovery by the public that the claim was false.
Confusingly, the top echelon of high-quality coffee roasters often don't bother to put the label "Arabica" on their packaging at all, as they figure that their coffee snob customers already know that a producer selling artisanal coffee would never consider using anything other than the good stuff. Another tip worth noting is that coffees that are made of 100% Arabica beans typically list "100% Arabica coffee" in their list of ingredients; whereas coffees that are 100% Robusta or a blend of both say something less specific such as "100% pure coffee" or "ground coffee" on the list of ingredients. As mentioned above, neither a list of ingredients nor any level specificity regarding species of coffee bean is not required on coffee labels by any regulatory body.
Should I Buy Coffee Labeled as "Arabica" or "100% Arabica"?
If price and caffeine are your primary concerns and you don't mind drinking something less tasty, go for Robusta, which is both far cheaper ($.93 per lb on the global commodities market vs $1.53 for Arabica) and contains almost twice as much caffeine per bean. As mentioned, the most premium of producers will typically not include the species of bean anywhere on their labels, as these coffee roasters feel that their consumers assume that the beans are Arabica due to the high quality of the product. My theory on the origin of this practice is the recent tendency of mid-tier coffee roasters (Starbucks, Dunkin') to plaster packaging with the Arabica label has resulted in the label being associated with mass market quality beans. Based on this tradition, realize that a package with the label "Arabica" may actually indicate a slightly lower quality blend. Overall, I'd go with Arabica if you care about taste, so stick with super premium producers or go with mass market blends that use the words "100% Arabica" on the label.
*The exception here is that some connoisseurs of traditional Italian-style espresso blends prefer the combination of Arabica and Robusta to achieve a mouth-coating, foamy effect in a shot of espresso known as crema. There is much debate about this blending process and whether this use of lowly Robusta is justified by flavor or just another effort to cut costs.