What is SL-09 ？ The Complete Dossier — Peru’s Inkawasi “Inca Geisha”
- Vela Ethan
- 44 minutes ago
- 12 min read
SL-09 (right — small and round) vs. Geisha (left — large and elongated) coffee cherries, photographed at Inkawasi.
In the cloud belt of the Inkawasi valley — 2,000 to 2,400 metres above sea level in La Convención, Cusco, Peru — grow coffee trees that local farmers have called “Inca Geisha” for generations.
They are not Geisha.
The complete file on Peru’s Inkawasi “Inca Geisha” | First-hand origin interviews × COE records × DNA fingerprinting
Vela Ethan Peru | June 2026
Prologue: a name that was wrong for decades
Summary. This dossier sets out the full history of SL-09: its selection and rejection at Kenya’s Scott Laboratories in the 1930s, the competing hypotheses for how it reached the highlands of Cusco, Peru, why it was called “Inca Geisha” for decades, the back-and-forth over its name in the Cup of Excellence record, and how two independent DNA fingerprinting tests finally established its identity. Sources: Vela Ethan’s first-hand Inkawasi origin interviews in 2024 and 2026, the official COE Peru records, and the DNA fingerprinting report produced by RD2 Vision for Sey Coffee in December 2024.
On 23 May 2026, coffee expert Scott Rao wrote on Instagram that if there were a coffee variety of the year, it would have to be SL-09 — and predicted that its price would double.
That same year, benchmark roasters across the US and Europe — George Howell, La Cabra, Cultivar Coffee, Moonwake, Sey Coffee — released Inkawasi SL-09 lots one after another. By the Inkawasi cooperative’s own count, Vela Ethan is the largest buyer of SL-09 from the region, and we began receiving enquiries from around the world.
But something else was happening at the same time: Peru suddenly “gained” large volumes of SL-09. Traders, cooperatives and smallholders in region after region turned out to have the variety on hand.
This is not necessarily anyone faking anything. The RD2 Vision report is explicit about the most common causes of varietal misattribution: planting material wrong at source, a name assigned merely because a tree “looks like” something, and natural crossing with neighbouring plots — Inkawasi itself is still working through the same problem. But whatever the cause, the result is the same: more and more coffee is being called SL-09, and less and less of it can be proven.
Behind the hype, this variety’s identity was blurred for close to ninety years. It was selected in Kenya in the 1930s and then abandoned. It crossed half the world to the Andes by a route no one can document. It changed names on the COE record more than once: a genetic test put it on the 2020 list as SL-09 for the first time, the auction market pushed the name back to Gesha the following year, and it then vanished from the record for three full seasons — until a second, independent DNA report at the end of 2024 finally made the name hold.
This article sets out the full story of SL-09, built on two first-hand materials: the DNA fingerprinting report produced by RD2 Vision for Sey Coffee, and Vela Ethan’s 2026 return to Inkawasi for in-depth interviews with the cooperative and its smallholders.
From Sey Coffee’s 2024 RD2 Vision report
Variety at a glance
Item | Details |
Name | SL-09 (also written SL9, SL09); locally called Inca Geisha / Inka Geisha |
Species | Coffea arabica |
Genetic group | Ethiopian Legacy — the same group as SL-34, SL-17, SL-14, K-7 and Mibirizi (RD2 Vision classification) |
Relationship to Geisha | Not closely related. Geisha sits in the Core Ethiopia (Ethiopian landrace) lineage; SL-09 sits in Ethiopian Legacy — two different genetic groups |
Selection origin | Scott Agricultural Laboratories, Kenya (est. 1903); single-tree selection in the 1930s from a stand of unknown provenance |
Main growing area | The heartland is the Inkawasi valley, La Convención, Cusco, Peru (2,000–2,400 m) |
Agronomy | Rated a shy bearer in Kenya and reportedly highly susceptible to Coffee Berry Disease (CBD); in Inkawasi the picture is the opposite — it out-yields Geisha, and it was one of the few varieties to survive the leaf rust epidemic |
Cup profile | Jasmine, bergamot and honeysuckle florals; passion fruit, lychee, peach and dragon fruit; honeyed sweetness, tea-like finish, bright acidity, with a faint spicy lift on the tail |
A note on the name: SL-09 is an old selection whose reference material is not necessarily well identified, and no authoritative public fingerprint is available for comparison. Because the profile matches the Scott Laboratories SL9 selection so closely, Sey Coffee and others use “SL9” as a provisional working name. SL9 / SL09 / SL-09 are used interchangeably in the market; this article uses SL-09 throughout.
1. Origin: the forgotten selection from Kenya’s Scott Laboratories
The SL series came out of Scott Agricultural Laboratories in Kenya, founded in 1903. In the 1930s the laboratory carried out single-tree selections from a stand of unknown provenance, numbering them from SL-1 onwards. SL-09 was one of them.
Unlike SL-28 and SL-34, which went on to fame, SL-09 disappointed the breeders in Kenyan fields: it bore little fruit, and it was highly susceptible to Coffee Berry Disease (CBD). In East Africa, where CBD is endemic, that is a fatal flaw. A 1956 Coffee Board of Kenya bulletin recorded the decision to discard it; apart from a single varietal-trial record in Malawi, SL-09 then vanished from mainstream breeding history.
There is a key geographic reversal here, worth remembering by everyone now watching SL-09: the RD2 Vision report notes explicitly that Coffee Berry Disease is endemic to East Africa but does not exist in the Americas. In other words, the fatal weakness that got SL-09 written off in Kenya poses no threat at all in the Andes. It did not become stronger in Peru — it finally arrived somewhere that suited it.
Worth adding, as recorded on London roaster Scenery Coffee’s website: their co-founder Alex brought back a batch of dried coffee cherries from a 2019 sourcing trip to Kenya and tried to germinate them in the UK — only 2 of 50 made it past the cotyledon stage, and one seedling was kept, growing inside their own café. Seven years later the tree is still alive; in 2025 it produced 500 grams of cherries, which were processed and cupped at an event in Manchester.
Later, when they sent a Colombian coffee (Luis Camacho’s Fragancia) off for genetic testing, they slipped in a leaf from that tree. It came back as SL9.
The sample was the tree in a British café — nothing to do with Peru. So this result speaks not to Inkawasi but to Kenya: officially, SL-09 was written off in 1956 and the record went blank; yet a batch of commercial cherries bought on a whim in 2019 still carried its seed.
2. How SL-09 reached Peru: an unresolved journey
There is no complete documentary chain explaining how SL-09 came to be growing in the high mountains of Cusco. The main hypotheses advanced by researchers such as Christopher Feran include:
The Tingo María station: the Tingo María agricultural experiment station, established with USDA assistance in 1942, received seed samples from the FAO’s Ethiopian collecting mission of 1964–65. During the Shining Path insurgency (1984–1988) the station’s archives were destroyed; seed may already have passed into farmers’ hands before then.
Confusion with Columnaris: another Scott Laboratories selection, Columnaris, has similar traits and may have circulated interchangeably with SL-09 in the early years.
Direct introduction: seed carried in independently from Ethiopia or Yemen by British planters.
The monastery seed: in recent producer accounts, Don Julio obtained seed from a monastery in 2011 and brought it back to Inkawasi, establishing the “mother trees”; the coffee began placing in local competitions from 2014.
Each account has supporters, and each has gaps. Precisely because the paper trail is broken, DNA testing is the only reliable tool for reconstructing SL-09’s identity.
3. My own encounter with SL-09: a variety I chased for six years
In 2021, Han Huai-tsung — Taiwan’s most influential coffee author and researcher, widely regarded as the founding figure of Chinese-language coffee writing — messaged me with a question he wanted help with: in the winning lots of the 2020 Cup of Excellence Peru, a variety name had appeared that nobody recognised — SL09.
Because of that, I asked Lucio Luque that year to photograph the trees and send the pictures over. But beyond photographs, no further information could be found anywhere. From that moment on, SL-09 became a coffee I was determined to buy.
The strange part: after 2020, the variety suddenly vanished from the COE lists.
In the 2020 COE Peru, four winning lots carried the label SL-09. Then in 2021, 2022 and 2023 — not a single one.
In 2024, I travelled to Inkawasi myself for the first time to find out why. Two flights, two changes of vehicle, a mountain pass at 4,550 metres — and the experience of watching my lips and fingertips turn purple from altitude hypoxia. Twenty-two hours after setting out, we arrived. That trip had one mission above all: to see the SL-09 trees with my own eyes.
And in that same year, 2024, the one and only COE Peru SL-09 lot finally reappeared on the list — Vela Ethan and Feeling Coffee (有容乃大) took it together at auction.
Then in 2025, three SL-09 lots appeared among the winners. Vela Ethan also joined the winning bid on the 3rd-place lot.
In 2026 we returned to Inkawasi and interviewed smallholders farm by farm. And on that trip we found a problem that remains unsolved to this day: roughly three quarters of the farmers still say first that they grow Inka Geisha — and only then add, “it’s also SL-09.”
4. The beautiful misunderstanding of “Inca Geisha” — and the COE record
It is not hard to understand why the farmers had the name wrong.
These trees were handed down from their grandparents. Farmers have worked them for generations, and nobody ever told them the botanical name. On the cupping table the coffee was intensely floral — like Geisha — so it entered the COE as Geisha. And that name stuck for many years.
According to the cooperative and its president, a leaf rust (La Roya) epidemic years ago killed off most of the region’s varieties, and this “tree that tastes like Geisha” was one of the few survivors. The trees that lived became the foundation of all of Inkawasi today.
The turning point came with the visit of an American green-coffee buyer. According to our interviews, after the Red Fox team came to origin they sent samples away for genetic testing — and the result confirmed that this “Geisha” was not Geisha. With a test result behind them, Inkawasi’s producers entered SL-09 into the COE record for the first time in 2020.
But the Asian buyers who drove the auction at the time did not know SL-09. Lots carrying the new name fetched less than they had as Geisha. The following year, many farmers changed the name back.
That is the real reason SL-09 “appears and disappears” in the COE database — the variety never went away; the name was bid back by the market.
5. The DNA evidence: two tests, one answer
Inkawasi’s first piece of genetic evidence came from Red Fox — it is what put the name SL-09 into the COE record in 2020. But that time, the evidence did not make the name hold: the market did not reward it, and within a year the name had been changed back.
What finally made SL-09 stand was a second report, four years later — commissioned by entirely different people and run through an entirely different laboratory.
Sey Coffee’s Lance Schnorenberg submitted Inkawasi leaf samples to RD2 Vision in France, under Dr Christophe Montagnon. The DNA was extracted by Adnid, RD2 Vision’s partner laboratory in France, and alleles were read across 11 SSR microsatellite markers (Sat11, CBD-Sat207, Sat225, Sat235, Sat24, Sat244, Sat254, Sat29, Sat32, Sat41, Sat47), with RD2 interpreting the results.
The sample was labelled Geisha Inca (sample code CO240217). The copy quoted in this article was provided by Sey Coffee to the Inkawasi cooperative, and by the cooperative to us.
Geisha Inca | Result: Rare Cultivar
Dr Montagnon’s interpretation makes four key points:
This is a very rare cultivar — Dr Montagnon states that he had never before seen this fingerprint in his own database.
It belongs to the “Ethiopian Legacy” genetic group. Known cultivars in this group include SL-34, K-7, Mibirizi — and SL-09.
“It is actually very close to SL-09, and it might well be it” — the report explains that because SL-09 is an old selection whose reference material is not necessarily well identified, a slight genetic difference is acceptable.
And the decisive line: “It is not an Ethiopian landrace and hence it is not even close to Geisha.”
The report adds two pieces of background. Of all the SL selections made in the 1930s, SL-28 and SL-34 are the most widely planted in East Africa today — SL-09 was never widely cultivated. And SL-09 is said to be extremely susceptible to Coffee Berry Disease (known locally as Ojo — not broca, the coffee berry borer), a disease endemic to East Africa but absent from the Americas.
The Arabica genetic groups: why SL-09 and Geisha cannot be the same thing
The second half of the report reproduces the Arabica genetic-group framework of Montagnon et al. (2022), which puts the distance between the two beyond argument:
Core Ethiopia — Ethiopian native landraces. Representative varieties: Gesha, Chiroso, Java
Domesticated Arabica, subdivided into: Ethiopian Legacy (SL-34, SL-17, K-7, SL-14, SL-09); Typica / Bourbon (Bourbon, Caturra, Catuaí, Mundo Novo, Typica, SL-28, Coorg); Harrar; and New Yemen
Geisha sits in Core Ethiopia. SL-09 sits in Ethiopian Legacy. They belong to two different branches of the family tree. This is not a question of resemblance — it is a question of pedigree.
6. The page of the report most worth remembering: why your variety often isn’t the variety you think
In its closing section, RD2 Vision devotes a full page to the common reasons why a fingerprinting result fails to match expectations. For a variety rising as fast as SL-09, this is the most important lesson in the entire document:
Case 1: the variety has nothing to do with what you expected. The planting material was wrong at source — human error or mislabelling by the supplier. “Often, a name will be given just because it ‘looks’ like a supposed variety (say Geisha) but in fact is very different genetically.” Or the source was correct, but human error or mislabelling occurred in your own nursery.
Case 2: genetically related to what you expected, but not pure. The seed plot itself was fine, but neighbouring plots held different varieties. Pollen carried by wind and insects landed on your flowers, producing uncontrolled crosses — and purity begins to erode. The more generations you replant from seed “contaminated” by neighbours, the more diluted the original variety becomes.
The report’s recommendation is a single sentence: source planting material from genetically verified sources. That sentence is exactly the problem SL-09 now has to face.
7. Field identification: how Inkawasi’s farmers tell SL-09 from Geisha
In high-mountain regions where genetic testing is not yet accessible, farmers have developed a practical set of field markers. The following is drawn from Vela Ethan’s 2026 origin interviews:
Marker | SL-09 | Geisha |
Leaf venation | Dense veins; narrow spacing between the lines | Wider spacing between the lines |
Cherry size | Small and round | Noticeably larger and elongated |
Tree form | Narrower spacing between branches | Wider spacing between branches |
Yield | Higher than Geisha | Comparatively lower |
Cup | Geisha-like sweetness, plus more extroverted tropical fruit and candy character, with a faint spicy lift on the finish | Elegant, clean florals |
Field identification has its limits, of course. Where SL-09 and Geisha are planted side by side and cross naturally, the offspring can carry traits from both parents and the naked eye becomes useless — exactly the second case RD2 Vision warns about.
The Inkawasi cooperative is therefore working through the region household by household and plot by plot, identifying each producer’s varieties and sending samples for genetic testing where necessary, so that every lot can carry a traceable identity.
8. Market outlook: can Inkawasi be to SL-09 what Panama is to Geisha?
In 2026, SL-09’s visibility reached a new high:
Scott Rao publicly named it variety of the year and predicted its price would double
Dr Kevin Shao of Taiwan and the Qingdao brand Coffee Buff introduced the variety to the Chinese-speaking market
George Howell, La Cabra, Cultivar Coffee, Moonwake, Sey Coffee and other benchmark roasters in the US and Europe released Inkawasi SL-09 lots
Trade media and coffee magazines ran features in succession
Cultivar Coffee of Dallas reached the finals of the inaugural Kenneth Davids Cup with its Oswaldo / Incahuasi Cusco SL-09 — a top-21 finalist for best washed coffee in the US, out of hundreds of coffees from 35 states and 14 countries
But the risks that come with the heat are just as real.
SL-09 seed has already begun to spread to other regions of Peru; add natural crossing with adjacent Geisha and generation-by-generation dilution of saved seed, and the coffees carrying the name “SL-09” will only multiply — while how many of them truly are SL-09 becomes ever harder to say.
We have shared the same view with the cooperative from the beginning: a variety name must not change with the market. Trust is accumulated over the long term — and once diluted, it takes many times the effort to win back.
Like the appellation systems of Bordeaux and Champagne, we believe Inkawasi can be to SL-09 what Panama is to Geisha: protecting the variety’s value through verifiable genetic identity and a clear, documented origin.
Vela Ethan will continue to work deeply in the Inkawasi region — bringing first-hand origin information, traceable lots, and a variety story that stands up to scrutiny to the Chinese-speaking and international markets.
References and sources
RD2 Vision — Coffee DNA Fingerprinting Report for Sey Coffee, Dr Christophe Montagnon (6 December 2024; the primary fingerprinting document behind this article — sample CO240217 Geisha Inca, 11 SSR markers, DNA extracted by partner laboratory Adnid) — https://rd2vision.com/the-arabica-coffee-cultivars-wheel/
Vela Ethan Peru — Inkawasi origin interview records, 2024 and 2026 (internal: smallholder interview audio, video, and farm photography) — https://velaethan.co
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