There are four main coffee types including Arabica, Robusta, Excelsa and Liberica. We all have heard about Arabica and Robusta and perhaps Liberica, but how much do you know about Excelsa coffee?
What is excelsa coffee?
Excelsa coffee is a unique, resilient, and productive species discovered in Africa in the early 20th century. Due to its minimal presence in the global coffee market, there is not much information available about how much of it is traded, roasted, or brewed.
Nobody knows about the exact origin of excelsa; all we know is it has been widely cultivated and consumed for many years in Asia and Africa.
This coffee was regarded as being low in cup quality with no distinctive flavor characteristics before, but when the ways of farming and processing it changed, excelsa beans turned into beans with positive, desirable, and unique flavors.
The origins of excelsa coffee
Nowadays, excelsa is cultivated in southeast Asia and India. But it was first discovered in 1903 in Central Africa where they call it dewevreié.
In 2006, it was realized that excelsa is not a species of the Coffea genus in its own right, so, it was reclassified as the dewevrei variety of the liberica species.
There are no official statistics on the production or trade of excelsa coffee because the International Coffee Organization (ICO) believes the demand for liberica coffee is not commercially significant.
Excelsa plant profile
Despite the excelsa’s reclassification in 2006, researchers are still debating whether or not it should be recognized as a species in its own right.
The best altitudes for growing excelsa trees are between 1,000 and 1,300 m.a.s.l. Excelsa is a tree-like plant (unlike arabica and robusta which are shrubs.) It means excelsa plant needs vertical space to grow. Excelsa plant is productive and resilient, but at the same time difficult to manage and needs extensive care.
Excelsa plant’s leaves are large and leathery and the flowers (bigger than those on arabica and canephora plants) bloom multiple times throughout the harvest season. The fruit maturation in excelsa tree takes almost a full year.
Excelsa beans shape and caffeine level
Excelsa beans are asymmetrical and have a length of 9mm and a width of 6mm on average. The beans contain less caffeine than canephora and arabica. The caffeine levels in 100 grams of excelsa beans range from 0.86 to 1.13 grams which are considered low compared to arabica and canephora.
Excelsa trees are resistant to many of the common pests and diseases and susceptible to trichomycosis, a fungal disease.
Is excelsa a variety or a species?
A fifth-generation coffee farmer says there are key differences in even the shape of the beans between excelsa and liberica. She believes the differences between excelsa and liberica beans are typically overlooked, and Indians group them together by calling both trees by the same name. she says the species vs. variety debate has not been ended after the reclassification in 2006.
According to the coffee farmer, studies and researches have shown high levels of genetic differentiation between excelsa dewevrei and other cross-pollinating liberica varieties, so, they should be considered separate species.
The challenges of growing excelsa
Excelsa trees need to frequent pruning due to their high productivity levels. But since they can get over 15 meters tall, pruning them can be difficult. More labor required for pruning increases the cost of production. Such difficulties are the reasons that excelsa hasn’t spread further afield among coffee producers.
One other issue is the species’ prolonged ripening period. The biggest problem is the lack of awareness: unlike what happens to the other marketed species, there are no improved cultivars or technological packages based on good research for the cultivation of excelsa and liberica coffee varieties.
The last problem is that even if there was interest in producing excelsa at a larger scale, regular trading at major volumes is impossible due to the lack of any established commodity market or standardized price.
Roasting and cupping excelsa coffee
Excelsa coffee farmed and processed with care can yield a complex and interesting cup profile.
Excelsa bean has a denser mucilage than arabica, and has far fewer soluble solids. It means that roast profiles for excelsa shouldn’t be derived from any other bean.
The lower solubility of excelsa means that to reach optimum flavor profiles, it may need to be roasted at higher temperatures or for longer periods.
Roasters say medium-light roasts produce berry-like and fruity notes, and woody and popcorn-like flavors. But a darker roasted bean yields a fuller body with notes of chocolate and cream.