A wild arabica with an extraordinary story
Of all the rare varietals in the speciality coffee world, few carry a history as remarkable as Sudan Rume. This is not a recent discovery, nor is it the product of a modern breeding programme. Sudan Rume is a genuinely wild arabica — one of the purest representations of Coffea arabica ever documented — and its influence on the coffee we drink today runs far deeper than most people realise.
Sudan Rume (also written as Rume Sudan) was first documented in 1941 by the economic botanist A. S. Thomas, who identified wild arabica trees growing on the slopes of the Boma Plateau in what is now South Sudan, close to the border with Ethiopia. The variety takes its name from the region and the locality of Rume, where the original selections were made. Unlike the cultivated arabica that spread from Ethiopia to Yemen and onwards across the tropics, these trees had grown in isolation in one of the very few remaining wild arabica populations outside Ethiopia itself.
Samples were sent to research stations in Tanzania, Kenya, and eventually the CATIE genetic collection in Costa Rica, where they were preserved for future study. For decades, Sudan Rume remained obscure — known to plant breeders but almost unheard of in commercial production.
Recent genetic studies have confirmed something extraordinary: the wild arabica populations on the Boma Plateau are genetically distinct from Ethiopian landraces, making South Sudan a legitimate second centre of origin for arabica coffee. The Boma Plateau is not simply a place where coffee happens to grow wild — it is part of the true ancestral home of the species, and Sudan Rume carries that unbroken genetic heritage directly in its DNA.
The hidden genetic legacy of Sudan Rume
Although Sudan Rume is rarely grown as a single origin coffee, its genetic fingerprint is everywhere in the modern speciality world. Coffee breeders quickly recognised that its wild genetics offered two invaluable traits: exceptional cup quality and strong resistance to Coffee Berry Disease. Crossed with higher-yielding varieties, Sudan Rume became one of the foundational building blocks of several of the most celebrated coffees in existence.
- SL-28, Kenya’s most famous varietal, is widely understood to carry Sudan Rume ancestry. If you’ve ever enjoyed the blackcurrant intensity of a top Kenyan coffee, you’ve had a distant encounter with Sudan Rume.
- Ruiru 11 and Batian, Kenya’s modern disease-resistant varieties, also draw on Sudan Rume genetics.
- Centroamericano H1, an F1 hybrid developed by CIRAD and CATIE for Central American farmers, is a direct cross between Sudan Rume and the rust-resistant Sarchimor line T5296. We frequently feature H1 varietal coffees from San Juanillo in Costa Rica.
- Milenion H10, another hybrid originating from a cross between rust-resistant T5296 and Ethiopian landrace Rume Sudan. We are in the process of planting H10 to replace old Geisha trees on our farm in Tarrazu, Costa Rica.
- Castillo and Colombia varieties, both staples of Colombian production, carry Sudan Rume somewhere in their lineage.
In a very real sense, much of the modern speciality coffee we drink today carries a whisper of the Boma Plateau. To taste Sudan Rume as a single origin, then, is to taste the wild ancestor itself — unmixed, undiluted, and unmistakably itself.
SL28 trees in a nursery in Kenya:
A cup profile like nothing else
What makes Sudan Rume truly remarkable is, of course, what ends up in the cup. It is rarely described in the same terms as other varietals, because it simply doesn’t behave like them. Sudan Rume offers something elusive — an elegant, layered, almost tea-like profile with a hint of herbal, savoury quality that sets it apart.
Typical tasting notes from a well-grown, well-processed Sudan Rume include:
- Delicate Florals: jasmine, honeysuckle, lavender
- Fruit: stone fruits such as apricot and peach, white grape, tropical notes like papaya and melon
- Citrus: lemon peel, bergamot, lemongrass
- Herbal and spiced: eucalyptus, cardamom, mint, cedar
- Body: silky, tea-like, with lingering natural sweetness
Unlike many varietals that lean hard in one flavour direction, Sudan Rume tends to unfold in layers as the cup cools. A single brew can move from bright citrus and florals in its early sips through to stone fruit and honeyed sweetness, finishing with a gentle, spiced herbal lift. It’s a varietal that rewards patience and attention — a slow, contemplative coffee rather than an immediately dramatic one.
Sudan Rume gained broader recognition in the speciality world when Sasa Sestic used it to win the 2015 World Barista Championship, bringing sudden international attention to a variety that had been quietly treasured by a small group of producers for years.
The challenges of growing Sudan Rume
Cultivating Sudan Rume is not for the faint of heart. The same genetic purity that gives it such a distinctive cup also makes it a genuinely demanding plant to farm commercially.
Very low yields. Sudan Rume produces significantly fewer cherries per tree than commercial varieties like Caturra or Castillo. This is the single biggest reason it is so rare — in pure economic terms, most farmers simply cannot afford to plant it at scale due to the low yield.
Uneven ripening. Cherries ripen unevenly across the plant, requiring multiple selective passes by pickers over the harvest period. Only fully ripe cherries are suitable for a microlot, which makes the labour cost per kilogram substantially higher than for conventional varieties.
Disease susceptibility. While Sudan Rume has stronger natural resistance to Coffee Berry Disease than many arabicas, it remains susceptible to coffee leaf rust. Producers must therefore pay close attention to farm management, shade, and plant health to protect their investment.
Specialised care. The plant itself has a tendency to grow tall and gangly, with fruit spread widely across long branches — similar in habit to Gesha. Regular pruning is essential, and the plant has specific nutrient requirements, particularly for phosphorous.
Precise post-harvest handling. Sudan Rume’s subtle, layered cup can easily be overwhelmed by aggressive fermentation or poor drying. The best lots come from producers who understand how to showcase the varietal’s delicacy without pushing it too hard.
Each of these challenges is a reason Sudan Rume remains genuinely rare on the speciality market — and also why every bag we can offer feels like a small privilege.
Try our Sudan Rume coffee from Arturo Arango
At Horsham Coffee Roaster, we’re thrilled to have secured a limited microlot of Sudan Rume from Arturo Arango, a young Colombian producer whose farm, El Paraiso, sits at 1,300 metres above sea level in Barcelona, Quindío. Arturo has been producing speciality coffee since 2015. After studying business administration in Colombia and completing a master’s in agroindustries in Argentina — where he first fell in love with speciality coffee — he returned home to produce some of the most thoughtful and precise microlots coming out of Quindío today.
Arturo Arango Sudan Rume — Washed
Tasting notes: Apricot | White Grape | Papaya
Process: 30-hour wet fermentation washed
Varietal: Sudan Rume
Origin: El Paraiso, Barcelona, Quindío, Colombia
Cup score: 87 points
Importer: Cofinet
Process: 30-hour wet fermentation washed
Varietal: Sudan Rume
Origin: El Paraiso, Barcelona, Quindío, Colombia
Cup score: 87 points
Importer: Cofinet
This stunning microlot has been processed using a carefully controlled 30-hour wet fermentation before being pulped, washed, and dried on raised beds. The controlled fermentation allows sugars, organic acids, and aromatic compounds within the cherry to develop gradually — a slow, deliberate approach that lets the delicate character of the Sudan Rume varietal come through with clarity.
Arturo’s attention to detail doesn’t stop at fermentation. Cherries are floated on arrival to remove lightweight or defective beans, and the water from floating is reused across batches before being filtered through specialised tanks and irrigated onto vetiver grass beds — a natural filtration system that purifies the water and returns oxygen to the soil. Every cherry is hand-sorted to remove anything under-ripe, over-ripe, or defective before fermentation begins.
The result is a cup that showcases Sudan Rume at its most refined: juicy apricot and white grape up front, papaya through the middle, and a silky, tea-like finish that lingers beautifully.
How we roast Sudan Rume coffee
Sudan Rume’s delicacy demands a light, attentive roast profile. Dudley, our head roaster, started profiling this coffee with multiple roasts on our Ikawa sample roaster to understand how it would behave. He found that typical roast profiles could easily result in an over roasted coffee. This meant approaching the coffee with great care on the Loring and roasting with short development and a relatively low end temperature. The Loring profile created sits at 9:20 with an end temperature of 207 degrees celcius and a development of just 10%. This approach protects the florals, bright acidity, and layered complexity that make the varietal so special.
For filter coffee brewing, start at 15g of coffee to 250g of water and adjust from there. We find that a filter is the best way to brew this subtle, delicate coffee, and you can find full brewing suggestions in our brewing guides.
Why Sudan Rume matters
Sudan Rume is a coffee that rewards the curious. It is rare, it is difficult to grow, it is low-yielding, and it doesn’t announce itself with the same immediate fireworks as some of its more famous descendants. But to drink a cup of it is to drink something very close to the wild origins of arabica coffee itself — a living link back to the Boma Plateau and the ancient forests.
At Horsham Coffee Roaster, we believe that every exceptional cup is an opportunity to understand coffee a little more deeply, its history, and the people who grow it. Sudan Rume, with its quiet rarity and its astonishing genetic story, is exactly the kind of coffee that reminds us why this pursuit matters so much.
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