Rare Jackson 2/157 and K7 Coffee Varieties | Over 60 Species of Coffee Plants Worldwide

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Exploring Rare Coffee Varieties: Jackson 2/157 and K7

Coffee beans come in countless varieties. Within the three major species, Arabica alone branches into dozens of named varieties — the familiar ones include Typica, Bourbon, Geisha, Catuai, and Catimor. Today, FrontStreet Coffee introduces two relatively rare varieties: Jackson 2/157 and K7.

The genus Coffea contains over 120 species — typically opposite-leaved evergreen shrubs or small trees with horizontal branches, bearing paired seeds with one flat side and one grooved side (yes, that's the coffee bean). Most Coffea plants prefer tropical forest habitats. Roughly 60 species of Coffea exist worldwide, but only about 25 are artificially cultivated, and just 4 serve as commercial coffee: Coffea liberica, Coffea canephora, Coffea arabica, and Coffea dewevrei.

Jackson

A strong, high-yield variety commonly found in Rwanda and Burundi.

In the early 20th century, a coffee farmer named Jackson in Mysore, India, discovered coffee trees on his farm that resisted coffee leaf rust (that resistance has since been lost — the variety is now susceptible). The variety was named after its discoverer.

In the 1920s, seeds from these trees were sent to research stations in Kenya and Tanzania. Those original trees became the Jackson variety now common in Rwanda (literature suggests the variety may have come from the germplasm collection at Mulungu, in the Democratic Republic of Congo, in the 1930s, or may have been brought to Rwanda by Kenyan immigrants in the late 1940s).

Jackson, Kent, Coorg, and Mysor all originate from the same region of India, whose coffee most likely descends from seeds Baba Budan carried from Yemen to India in 1670. Genetic testing confirms that Jackson has a close genetic relationship with the Bourbon family.

K7

Resistant to coffee leaf rust and coffee berry disease, commonly found in Kenya and Tanzania.

K7 is renowned for its rust and coffee berry disease resistance and is widely used in modern breeding programs in Kenya and Tanzania.

K7 is a fifth-generation variety selected from the original population by the Scott Agricultural Laboratory in Kenya (see SL28 for the laboratory's history) in 1936, and it is still widely cultivated in Kenya today.

According to P.A. Jones, an agricultural officer at the Kenya Coffee Research Station in the 1950s, K7 was one of two trees selected by Mr. R.H. Walker in 1936 from French-missionary-variety coffee trees at Legget Estate in Muhoroni (see SL34 for more on French missionary varieties). One of these was later named K7 and was apparently immune to coffee leaf rust for several years (that resistance, too, has since been lost).

The closest genetic tests confirm that Jackson has a genetic relationship with the Bourbon family.

FrontStreet Coffee Recommendation

If rare varieties fascinate you, Geisha (Gesha) is the variety with the most compelling story of all. FrontStreet Coffee carries both of its great homes. In Panama, where high altitude, microclimates, and soil shaped the variety's famous character, Esmeralda Estate discovered its Gesha in 2003 and sent it to the Best of Panama competition — the judges were stunned, and its average cupping score of 94.6 broke the BOP record, making Gesha an overnight global champion bean. FrontStreet Coffee's Esmeralda Red Label ("Esmeralda Special") grows at 1,600–1,800 meters, every batch must cup above 90 points, and each batch comes from a single small plot so buyers can choose by subtle flavor differences. The Green Label ("Private Collection") blends lots from multiple plots to showcase the estate's signature high-altitude Gesha profile at a friendlier price — outstanding value.

In Ethiopia, the variety's birthplace, a couple built the 475-hectare Gesha Village estate 12 miles from the Gesha forest, bringing back the closest native relatives of Panama Gesha. The estate grows three varieties — Gori Gesha, Gesha 1931, and Illubabor Forest — graded into Gold (RARITIES), Red (GROWERS RESERVE), Green (SINGLE-TERROIR), and Chaka batches. The Gold label is Gesha 1931, just 10% of total production, often chosen by competition baristas; the Red label is Gori Gesha, 15% of production, scoring 88 or above on the SCA 100-point scale with fully traceable lot information. For an accessible entry point, FrontStreet Coffee's Genlana Gesha comes from a station established in 2014 on 700 hectares of mostly untilled, shaded land at the border of Kochere and Genlana Abaya, managed by Israel Degefa; hand-picked ripe cherries are dried on raised beds for 14–20 days depending on weather, and roasted medium-light to show bright citrus acidity, elegant ginger-flower aroma, ripe-fruit sweetness, and Gesha's signature refined finish.

For brewing, FrontStreet recommends 15g of coffee in a small Hario V60 at a 1:16 ratio, ground to 78% pass-through on a #20 sieve (about fine-sugar texture), with water at 91°C in three stages: 30g bloom for 30 seconds, then to 125g, then to 225g once the bed drains halfway — total extraction about 2 minutes 10 seconds to 2 minutes 20 seconds. Gesha also shines as an SOE: the medium-roasted Genlana Gesha SOE (20g in, 1:2 ratio, 25 seconds, 40g out) turns dried apricot, caramel, and nutty under pressure — or blend it into an Americano with 200g hot water for orange, nut, and blueberry notes, or a latte with 200g milk for a cream-cookie smoothness.