Not all coffee trees are the same, and the entire industry might depend on their differences.
In our last summer school session we talked about processing. Today, I’d like to continue the journey towards understanding why different coffees taste different from each other by going back a few steps. Let’s delve into a concept that is perhaps easier to understand, yet harder to really hone in on its impact: variety.
Variety is easy to understand, because we’re already familiar with it as a general concept. Take apples or wine grapes as an example, if you’ve been to a supermarket, you’ve seen different kinds of apples (macintosh, fuji, honey crisp if we’re being fancy) and if you’ve been to a liquor store, you’ve seen different kinds of wines (chardonnay, chenin blanc, pinot noir). And even if you’re not an expert on exactly how those differences affect flavor, you probably at least believe that those varieties all taste different.
In addition to taste, variety plays a role in the physical appearance of plants (like leaf shape, cherry color, and height), their adaptability to various kinds of soil and growing conditions, and their resistance to diseases. So, for example, one variety might taste better than another, but if it’s more likely to be wiped out by a disease like coffee rust, it might not really be worth it for a farmer to take that risk.
All wine grape varieties come from the same species (Vitis vinifera) and all apple varieties come from the same species (Malus domestica). Coffee is slightly more complicated; though there are over 100 species in the genus Coffea, we get pretty much all of our drinkable coffee from two main ones: coffea arabica and coffea canephora (which often gets called “robusta”). Most of the coffee you buy from Trade or any other specialty shop will be made from varieties of Arabica — which are slightly less caffeinated, but way more delicious.
If you’ve been keeping up with our country-specific posts, you know that coffee was first discovered in Ethiopia, and the travel out from Ethiopia begins to explain how we get all these different varieties throughout the world. Though there are thousands of varieties in Ethiopia, not all of them (in fact very few of them) are responsible for the coffee spread through the rest of the world. One of the coffees exported from Ethiopia out to Yemen and then the Indonesian island of Java gets taken by the Dutch back to the Netherlands and then out to South America and, through the French, Central America. That variety is what we call Typica. The French also took a tree from Yemen to the island of Bourbon off the coast of Africa, from which it spread to the parts of East Africa that aren’t Ethiopia, and back over to Brazil (and then Central America). That variety is what we call Bourbon. So just two different trees are responsible for populating most of the world with coffee beans.
From there, mutation, selection, and hybridization have created many new varieties and cultivars (a term we use for varieties that have had some human influence in their creation) in the new world. For example, Caturra, one of the most grown varieties in the Americas, was a mutation of Bourbon discovered in Brazil in the early 1900s. SL-28 and SL-34 are two famous varieties that were “created” at Kenya’s Scott Labs, also in the first half of the 20th century. “Created” here, it’s important to note, means not some nefarious genetic modification process, but rather taking a bunch of coffee trees, figuring out which ones have qualities you desire, and breeding it until it becomes a stable variety ready for distribution.
The most popular and easy-to-understand method of creating new varieties is hybridization, where two different varieties are crossed, and the resulting trees that get the best of both worlds are selected. The reason I wrote earlier that “most” of the specialty coffee you get is from the species Arabica is the existence of the Timor Hybrid, which was found on the island of Timor and is a naturally occurring hybrid of Arabica and Robusta. It’s important as a variety grown in Southeast Asia, but arguably even more important in its use for creating other hybrids. If you can get Timor and Caturra, for example, to combine in a way that selects for the tastiness of Caturra and the disease-resistance of Timor, you get varieties (called, in this case, Catimors) that are very useful to farmers.
The organization World Coffee Research has created an unbelievable variety catalog for farmers to learn about what varieties might work well for their specific needs. In theory, this should allow for farmers to plant new varieties and improve their quality and yields. In practice, this is still a huge financial risk. Even if the new variety grows on the farm without a hitch — which is far from a sure thing — you won’t see the very literal fruits of your labor for several years. To mitigate at least that first risk, WCR has also launched their International Multilocational Variety Trial. They’ve taken 30 varieties and planted them in over 40 locations worldwide, to measure how they’ll perform in diverse coffee growing environments. It’s by far the most ambitious project of its kind, not just because it will lead to interesting new combinations of variety and place, but because it should hopefully help farmers plant trees that will be more likely to survive upcoming changes in climate.
So, we have lots of varieties and some idea of where they came from, but which should you be looking for? The Gesha variety is arguably most famous in specialty coffee. It’s also arguably the only variety that the industry has successfully marketed as tasting a specific way (for more about marketing Gesha and its name, I highly recommend Jenn Chenn’s excellent Sprudge article). Geshas often taste like super-sweet fruit and flowers, which is why they tend to command high prices. Because of that potential value, most Gesha is planted in places, processed in methods, and roasted in ways that really get those flavors across. So if you see Gesha on a bag, odds are there’s a candy-like coffee in there.
The Pacamara is another intriguing and distinctive variety. This hybrid of the Pacas and Maragogype was developed in El Salvador and stands out before you even taste it with its gigantic coffee beans. Pacamaras have potential for outstanding fruity notes and clean acidity, but they also occasionally have a very slight savory note that with certain coffees goes into green onion territory. Wild!
There are other varieties, like SL-28 and SL-34, that can give you a pretty good idea of what a coffee’s going to taste like (high possibilities of citrus, blackcurrant, savory notes), but because those varieties are so highly linked to Kenya (and rarely grown outside of it), you’ll probably get that same information just from seeing Kenya on the bag.
For other, more widely planted varieties, like Caturra and Bourbon, it’s harder to use the variety to garner a ton of information about what the coffee tastes like. That’s not to say it’s not important: to farmers, the choice of what variety to plant is always crucial, and if you’re based in a specific coffee growing region and constantly tasting different varieties grown in that one region, you’ll tell the difference. But with those varieties being planted at so many different elevations in so many different countries, and being processed and roasted in so many different ways, it’s hard for a coffee drinker tasting from all around the world to zero in on what those particular varieties bring to the flavor table.
More often than not, variety isn’t the data you see on a bag of coffee that should decide whether or not that coffee is for you. But is it an absolutely fascinating facet of coffee production, and one of, if not the, most important fields of coffee research happening today. In these increasingly uncertain times, new varieties and old varieties planted in new places could hold the key to making sure we have delicious coffee for years to come.