Liberica & Excelsa | The Future of Coffee?

(Fruit-bearing Liberica trees // Hana Choi, 96B cafe & roastery)

Over 100 species of coffee grow in the wild today, but only two dominate the market. Arabica (probably what you’re drinking now) takes about 60% of the market, and Robusta takes the other 40%. As climate change troubles both of these crops, especially Arabica, two other alternatives have been discussed by academics and producers: Liberica and Excelsa. In fact, this is not the first time these species have saved coffee from ecological disaster. 

This year, we’re partnering with 96B cafe & roastery in Vietnam to bring a blend of these unique coffees to our shelves. They’ve worked hard for almost a decade to produce high quality, specialty Liberica and Excelsa coffees, and they’ve found great success.

Research on these coffees is still actively ongoing. Until 2024, these two crops were actually seen as sub-varieties of the same species. However, new research has come to light indicating that these truly are two different branches on the tree of life. Research like this is vital to determine the crop’s effectiveness as a commercial solution, as is the work that 96B is doing to bring Liberica and Excelsa to focus on quality.

Liberica coffee (C. liberica var. liberica) as introduced to Sri Lanka in the early 1870s. (Source: Dr. Aaron Davis)

History

Liberica’s initial commercialization dates back to the early 1800s, but it rose to prominence during the 1870s when an epidemic of leaf rust tore through Southeast Asia. Leaf rust is a fungal parasite which targets the Coffea genus, spreading its spores across the leaves and limiting the plants ability to photosynthesize. 

Arabica was particularly susceptible to leaf rust, causing farmers to seek out alternatives. Liberica immediately displayed a stronger resistance to the fungus, and by the end of the century, it actually rivaled Arabica’s position as the top coffee species in the global market.

In 1899, the first Excelsa crop was identified, and was understood as a sub-variety of the Liberica species. This variety was seen as superior to Liberica. It had higher yields, easy to pick clusters of cherries, and a soft pulp, which made it easy to extract the seed.

This dominance turned out to be pretty short lived. Liberica production fell dramatically after 1900, probably due to low quality and a strange flavor profile. Today, some people report that Liberica makes up 1% of the market, but it is probably much less than that. Some estimates say that only 1000 metric tons of Liberica are produced annually. This production is based in Africa, Malaysia, the Philippines and parts of Indonesia.

Lately, there has more effort to ramp up production of Liberica and Excelsa. Both of these crops can grow in lower elevation (0m - 1000m), as well as hotter and more humid climates. Arabica, and even Robusta, have struggled in the face of droughts and changing climates. Liberica and Excelsa may prove to be better alternatives in the long run.

(Coffee leaf comparison: Liberica leaves are noticeably larger than other species’, dark green, 20-30cm long, and have a leathery texture // CATIE Collection)

Characteristics

But is Liberica a worse coffee? Given how dramatically its influence dropped, you might think so, but the real story is more complicated than that. It all comes down to post-harvest production. After coffee cherries are picked, they must undergo a particular process to effectively remove the seeds and preserve flavor, and this process has a significant impact on the flavor and quality of the cup. 

It turns out that processing is especially difficult with Liberica cherries. They stick to the tree once they ripen, which makes harvesting easy, but also opens up greater risk for overripe cherries. The pulp—the fruity bit of the cherry—is also a lot tougher than Arabica and Robusta, which makes depulping more labor intensive. It seems likely that quality concerns in the 1800s were due to post-harvest processing rather than issues with the plant itself.

The flavor of Liberica is undeniably unique, compared to its counterparts. Arabica is well known for sweet, caramel notes and a generally citrus-like acidity, while Robusta tends to have harsher, more bitter flavor notes, and a higher caffeine content. In contrast, Liberica has a very floral profile, often described as a tea-like taste. Because the beans are much bigger, there is more surface area of the bean to absorb sweetness from the cherry. At the same time, it can have a woody, even vegetal taste that may be unpleasant if roasted too dark.

Liberica trees are huge, with big, wide leaves. In fact, 96B’s first supplier was from a farm that only used them as a shade trees, providing cover for their Robusta crop. As mentioned above, the cherries are also quite large, with a tough pulp that makes them difficult to process. The beans themselves are also pretty big compared to Arabica, and they have an unusually oblong shape. This shape can actually provide a challenge for roasters trying to achieve a uniform roast level.

Liberica vs. Excelsa

So far, I’ve referred to these two coffees as a whole, because that is how they’ve been studied for over a century. However, research indicates they are actually two separate branches of the Coffea genus. A new study led by Dr. Aaron Davis, an expert on coffee and crop development, pointed out that there are too many differences between the two crops for them to fall under one umbrella. 

The primary difference between the two lay in the actual physical characteristics. Excelsa tend to have smaller cherries, and a softer pulp (which makes processing much easier!) While they both have large leaves, the Excelsa leaves have a much wider span.

In addition, each plant naturally grows in slightly different climates. Excelsa likes to grow in places with low, but consistent overall rainfall. Liberica can grow in regions with much higher rainfall on average, even with months-long stretches of drought in between. To make the point even clearer, the two “varieties” are rarely ever grown together.

His research concludes that the two are totally different species, rather than varietals, and he says that this understanding is crucial for crop development, as both species are under threat of extinction. 

96B Cafe & Roastery

96B is a coffee roaster and retailer based in Vietnam, and I recently had the pleasure of speaking with its cofounder, Thai Dang, about their Liberica project. They first identified some cultivated Liberica trees in 2016, and they have spent the last decade perfecting their processing methods.

In this project, 96B takes the role of the producer as well. They purchase whole cherries from the farms, and they have developed their own strategy for sorting and processing the seeds inside. For many years, they only featured Liberica and Excelsa in blends with more established Robusta crops. It is only in recent years that they have sold offerings of Liberica and Excelsa on their own.

The coffee we’ve purchased from 96B is a blend of the two species. The ripe cherries were dry fermented for 120 hours after picking, then slow-dried for 30 days. The result is a unique cup with notes of peach tea, stevia leaf, and papaya.

Conclusion

Climate change has been a big contributor to rising coffee costs in recent years. Vietnam and Brazil have both experienced major droughts, and deforestation continues to encroach on coffee’s natural habitats all over the world. Research into new species like Liberica and Excelsa isn’t just a novelty, it may be crucial for coffee’s survival in the future. Especially, since they’ve shown to be resilient during a crisis in the past.

The recent discoveries made by Dr. Davis only make the point clearer. There is so much we still don’t know about both of these crops. Given that their piece of the market is so small, we will have to do more research to see if these plants really are as resistant to drought and disease as we hope.

The work 96B is doing is of equal importance. Low quality is the reason Liberica didn’t catch on a century ago. For either of these coffees to have market success, it is crucial that techniques are developed to reliably produce high quality coffee from these cherries. We think 96B has made something truly special in their decade of work.

At Solid State, we love to feature unique coffees and explore all the coffee world has to offer. I first read about Liberica a few years ago, and I’ve been eager to feature one on our shelves ever since. Because of that, I am so excited about the beginning of this partnership with 96B. Personally, I think it’s a really special coffee to offer to our customers, and something you can’t find anywhere else in the city.