Arabica
Rume Sudan
Also known as: Rume Sudan (RS)
Rume Sudan is an Ethiopian landrace variety that was collected from Sudan (now South Sudan ) in the 1940s. It is valued for its unique, complex cup profile and its genetic diversity, which makes it important for coffee breeding programs. Rume Sudan is increasingly planted as a single- variety specialty coffee.
Key Takeaways
- Rume Sudan was collected from the Boma Plateau region of Sudan (now South Sudan) in the 1940s.
- Rume Sudan is an Ethiopian landrace, genetically distinct from Typica and Bourbon lineages.
- Rume Sudan is valued for its genetic diversity and is used in breeding programs to introduce new genetics.
- The Boma Plateau in South Sudan is one of the few places where wild Arabica coffee grows naturally.
Rume Sudan is an Ethiopian landrace variety that was collected from Sudan (now South Sudan ) in the 1940s. It is valued for its unique, complex cup profile and its genetic diversity, which makes it important for coffee breeding programs. Rume Sudan is increasingly planted as a single- variety specialty coffee.
Rume Sudan is an Ethiopian landrace variety that was collected from Sudan (now South Sudan) in the 1940s. It is valued for its unique, complex cup profile and its genetic diversity, which makes it important for coffee breeding programs. Rume Sudan is increasingly planted as a single-variety specialty coffee.
Origin
Collected from the Boma Plateau region of Sudan (now South Sudan) in the 1940s.
History
Rume Sudan was collected from the Boma Plateau region of Sudan (now South Sudan) in the 1940s by British botanical explorers. The variety was brought to Kenya for research and has been maintained at various coffee research stations. Rume Sudan is an Ethiopian landrace, meaning it is a locally adapted variety from the region where Arabica originated. In recent years, Rume Sudan has gained attention in the specialty coffee industry for its unique cup profile and genetic diversity.
Discovery
Collected from the Boma Plateau region of Sudan (now South Sudan) in the 1940s by British botanical explorers.
Genetics and Lineage
Rume Sudan is an Ethiopian landrace, meaning it is a locally adapted variety from the region where Arabica originated. It is genetically distinct from the Typica and Bourbon lineages that form the basis of most cultivated Arabica. This genetic distinctiveness makes it valuable for breeding programs.
Parent Varieties
Hybrid Status: Not a hybrid. Rume Sudan is a landrace variety collected from wild populations. It has been used in breeding programs to introduce genetic diversity.
Growth Characteristics
Rume Sudan is a tall, vigorous tree with bronze-tipped young leaves. It has a conical growth habit typical of Ethiopian landraces.
Tree Size: Tall (3 to 4 meters at maturity)
Yield: Low. Rume Sudan yields less than modern varieties, which limits its commercial adoption.
Disease Resistance: Moderate. Rume Sudan has some natural resistance to pests and diseases due to its wild origin, but it is susceptible to coffee leaf rust.
Climate and Growing Conditions
Rume Sudan thrives in East African highland conditions at elevations of 1,400 to 2,000 meters. It requires well-distributed rainfall and fertile, well-drained volcanic soils.
Climate Preferences: Tropical highland climate. Optimal temperatures 15 to 24 degrees Celsius.
Rainfall: 1,200 to 1,800mm annually, well-distributed.
Elevation Range: 1,400-2,000 meters
Processing Compatibility
Rume Sudan is excellent with all processing methods. Washed processing highlights its clean, complex acidity; natural processing enhances its fruit sweetness and body.
Roasting Behavior
Rume Sudan beans are dense and take heat well. Light to medium roasts best preserve its complex acidity and fruit notes.
Cup Profile
Rume Sudan has a complex, unique cup with bright acidity, a juicy body, and distinctive notes of stone fruit, berries, citrus, and sometimes floral or herbal notes. The cup is complex, elegant, and unlike Typica or Bourbon varieties.
Acidity
Bright and complex.
Sweetness
High, with stone fruit and berry sweetness.
Body
Medium, juicy.
Professional Cupping Notes
Rume Sudan lots can score 87 to 91+ points in SCA cupping. It is valued for its unique, complex character and genetic diversity.
Common Defects
- •Susceptible to coffee leaf rust
- •Low yield limits commercial adoption
- •Prone to potato defect in some regions
Brewing Recommendations
Rume Sudan excels as pour over to highlight its complex acidity and fruit notes. Recommended brewing temperature: 90 to 95 degrees Celsius.
Countries Where Grown
Notable Farms
Interesting Facts
- •Rume Sudan was collected from the Boma Plateau region of Sudan (now South Sudan) in the 1940s.
- •Rume Sudan is an Ethiopian landrace, genetically distinct from Typica and Bourbon lineages.
- •Rume Sudan is valued for its genetic diversity and is used in breeding programs to introduce new genetics.
- •The Boma Plateau in South Sudan is one of the few places where wild Arabica coffee grows naturally.
Frequently Asked Questions
Sources
- •World Coffee Research
- •Specialty Coffee Association
- •Royal Botanic Gardens, Kew
Related Varieties
Arabica Coffee Varieties: Origin, Flavor & Genetics
Arabica is known for its complex, aromatic, and nuanced flavor. It generally has higher acidity, lighter body, and more aromatic complexity than Robusta. Notes range from floral and citrus (highland African) to chocolate and caramel (Central and South American). Sweetness is generally high, with clean, balanced cups being the hallmark of quality Arabica.
ArabicaBatian
Batian was developed to combine disease resistance with the cup quality of SL28. Well-grown Batian produces a bright, juicy cup with notes of blackcurrant,...
ArabicaEthiopian Landrace
Ethiopian landraces produce some of the world's most distinctive and complex coffees. Flavor profiles vary by region: Yirgacheffe is known for floral, citrus, and tea-like notes; Sidamo for fruit and berry; Harrar for blueberry and wine; Guji for stone fruit and floral. The cups are generally bright, complex, and elegant.
ArabicaSL28
SL28 is renowned for its intensely fruity, juicy, and complex cup profile. It has bright, wine-like acidity, a juicy body, and distinctive notes of blackcurrant, blackberry, tomato, and sometimes citrus. The cup is bold, complex, and unmistakably Kenyan.
ArabicaSL34
SL34 has a rich, complex cup with a heavier body and darker fruit notes than SL28. It has bright acidity, a full, syrupy body, and notes of blackcurrant, plum, dark cherry, and chocolate. The cup is complex, rich, and less overtly fruity than SL28.
Related Encyclopedia Entries
Acidity
In coffee tasting, acidity refers to the bright, vibrant, and often fruity quality that gives coffee its liveliness and structure. Unlike the negative connotation of acidity in everyday language, coffee acidity is a desirable characteristic when balanced. It is perceived as a pleasant tartness or brightness on the palate, similar to the acidity in wine or fruit.
Origins & GeographyCoffea Arabica: The Specialty Coffee Species Explained
Arabica coffee (Coffea arabica) is a species of coffee plant native to the highland forests of Ethiopia and South Sudan. It is the most widely cultivated coffee species worldwide, accounting for approximately 60 to 70 percent of global coffee production. Arabica is prized for its complex flavor, refined acidity, and aromatic diversity, producing notes ranging from floral and citrus to chocolate and caramel depending on origin, variety, and processing.
Coffee ScienceCoffee Leaf Rust
Hemileia vastatrix belongs to the order Pucciniales and is an obligate biotrophic fungus, meaning it requires living host tissue to survive. The infection cycle begins when urediniospores are deposited on the abaxial (underside) surface of the coffee leaf, typically via wind or rain splash. Germination occurs only in the presence of free water—such as dew or rainfall—within a temperature range of 15°C to 28°C. Upon germination, the fungus enters the leaf through the stomata and establishes a mycelium that colonizes the internal tissue. The visual manifestation of the disease begins as small, chlorotic spots that expand into characteristic orange, powdery pustules. These pustules contain thousands of spores capable of further infection. The physiological impact includes a rapid reduction in photosynthetic capacity and the eventual abscission of the leaf. Severe cases lead to 'dieback,' where the plant's branches wither due to carbohydrate depletion, often resulting in the death of the tree or a total loss of the following year's crop.
Origins & GeographyEthiopian Coffee: The Birthplace of Arabica Coffee
Ethiopia is widely considered the birthplace of coffee, where the Coffea arabica plant originated in the highland forests of the southwest. Ethiopia remains one of the world's top coffee producers, known for extraordinary genetic diversity, distinctive regional cup profiles, and processing traditions that date back centuries. Regions like Yirgacheffe, Sidamo, Guji, and Harrar produce some of the most sought-after specialty coffees in the world, prized for their floral, citrus, and tea-like characteristics.
Coffee ScienceExtraction
Extraction is the process of dissolving soluble compounds from ground coffee into water, producing the beverage we know as coffee. During extraction, water pulls acids, sugars, lipids, carbohydrates, and melanoidins from the coffee grounds in a sequence that shapes flavor, body, and aroma.
Varietals & CultivarsRume Sudan Cultivar
Rume Sudan is an indigenous wild Coffea arabica variety from South Sudan crucial to global coffee genetics for its natural CBD resistance.
Coffee CultureSpecialty Coffee
The classification process necessitates precise environment control. During the grading phase, the coffee is roasted within 24 hours of cupping and allowed to rest for at least eight hours. The roast level must fall within the light to medium range, specifically between 55 and 65 on the Agtron scale. Cupping involves a standard ratio of 8.25 grams of coffee per 150 milliliters of water, with water temperatures maintained between 92.2°C and 94.4°C (198°F to 202°F). This protocol ensures that the inherent characteristics of the bean—such as the phosphoric acidity typical of Kenyan origins or the stone fruit notes of Colombian Caturra—are evaluated without the interference of roast-induced flavors.
Related Book Chapters
- •Chapter 4: Varietals & Cultivars
- •Chapter 2: Coffee Origins
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Keith E. Lyons
Author, Researcher & Coffee Educator
Keith E. Lyons is the author of The Complete World of Coffee and the publisher behind Lyons Den Publishing. A licensed trauma therapist turned specialty coffee writer, Keith blends scientific rigor with genuine passion for the craft of coffee.
Last Reviewed
August 5, 2026
Sources & References
(3)Claims are cited to verifiable sources. Peer-reviewed research is marked.
- 1World Coffee Research
- 2Specialty Coffee Association
- 3Royal Botanic Gardens, Kew
Authoritative References
Editorial Standards
- • Fact-checked against peer-reviewed coffee science research and industry standards.
- • Reviewed by the author with documented sources for every factual claim.
- • Updated regularly; the "Last Reviewed" date reflects the most recent verification.
- • Corrections are made promptly when new research or evidence emerges.
Our editorial process prioritizes accuracy, scientific rigor, and practical relevance for coffee enthusiasts and professionals alike.
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