SL-28 & SL-34
Varietals of Bourbon that were selected by Scott Laboratories (hence SL) in Kenya during the colonial years.
Coffee Farming
Coffee farming in Kenya
Coffee was first grown in Kenya by Roman Catholic Fathers at St Austin’s near Nairobi in 1889. From then on it has proved to be quite popular and has over the years formed a major export commodity of Kenya. The species grown are Arabica and Robusta. The Arabica is a high quality, mild coffee much favoured for blending. The two coffee species are grown mainly by small scale farmers in the following regions:
- Central region — Nyeri,Murang’a, Kiambu, Thika, Kirinyaga.
- Eastern region — High areas of Meru Central, Embu, Machakos, Tharaka and Makueni.
- Coast region — Taita Taveta (Wundanyi area).
- Westem region —— Bungoma,Vihiga, Kakamega.
- Nyanza region — Kisii, Nyamira, Nyabondo Plateau in Nyando area and Oyugis in Rachuonyo
Grades for Kenyan Coffee
- *AA
- *AB
- *C
- *PB
- *T
- *TT
- *UG1
- *UG2
- *UG3
Kenyan beans are graded by bean size
and density. Larger size is generally associated
with more flavor & aroma. AA is the highest graded
coffee in Kenya and offers better cup clarity,
AB offers more complexity in taste balance.
Conditions that Favour Coffee Farming
Kenya is the leading producer of Arabica coffee in Africa. Below conditions favour its production in the country:
- Temperature – Coffee does well under temperatures of 14 to 26°C although Arabica coffee can tolerate temperatures of upto 30°C. In Kenya the coffee growing areas experience cool to hot climate ideal for coffeee growing. The temperatures average 15°— 30°C.
- Rainfall – Arabica coffee requires rainfall ranging between 1000 and 2 000 mm per annum. Many coffee growing areas in Kenya receive high rainfall of about 1000 — 2000 mm which is well distributed.
- Soils – Most of the growing areas in Kenya have fertile deep volcanic soils which are suitable for coffee. The soils are well drained and are acidic with a pH of between 5.3 and 6.0.
- Topography – The coffee growing areas have undulating landscape with hill slopes and gentle slopes. This has ensured well drained and aerated soils.
- Altitude – Most of the growing areas have a high altitude ranging between 610 m and 1,830 m. However in a few areas like Machakos, coffee is grown at slightly lower altitudes.
- Transport – The growing areas have good roads which has enabled the crop to be transported to the buying centres and factories. This has also helped in marketing of the processed berries.
- Labour – Coffee growing is labour intensive. A lot of manual labour is required for. Planting, running and harvesting. The dense population in the growing areas has provided a source of labour.
SL-28
Known for it’s sweetness, blackcurrant-like acidity & high complexity. Great cup quality, some of the most treasured cups.
Image unavailable in the original archiveSL-34
SL-34 is grown in middle altitudes. Better yield than SL-28.
Image unavailable in the original archiveRuiru 11
Ruiru 11 is named after the Coffee Research Foundation station in Ruiru, Kenya, where it was developed in the 1970s.This composite variety was created through an intensive Arabica-Robusta hybrid breeding program involving Rume Sudan, Timor Hybrid lines, K7, N39, SL-28, SL-34, Bourbon, and Catimor lines, among others.Developed as a response to the coffee berry disease crisis in 1968 that led to loss of half of Kenya’s coffee production, Ruiru 11 is high yielding, and hardy variety. Its compact stature allows Ruiru 11 to be planted at a density of 2500 – 3300 trees per hectare, compared to the typical planting density of 1300 trees per hectare. It also has an added benefit of producing coffee cherries earlier in the season.
Image unavailable in the original archiveTaste Profile
A typical cup of Ruiru 11 has many qualities of a good Kenyan coffee, including citric juicy acidity and good body.
Screening and Grading
| Grade | Type | Screen | Description |
|---|---|---|---|
| C | Kenya C | medium Screens: 14 and 15 | The size of the bean is even smaller and further reduces the chemical compounds and ultimately the flavor intensity |
| PB | Peaberry | medium Screen 16 | These are round beans which usually grow in a single cherry bean. |
| TT | Light Beans | medium Screen 15 & 18 | TT is smaller still, made from the smaller beans removed from lots of the more illustrious grades |
| AA | Kenya AA | large Screens: 17 and 18 > 7.2 mm | These are the most popular and sought coffees because of their shape, body, acidity and flavour. |
| AB | Kenya AB | large Screens: 15 and 16 = 6.6 mm | A combination of A (Screen 16/6.8mm) and B (Screen 15/6.2mm) sized beans. |
| E | Elephant | very large Screen 20 | This is the largest of all grades in size and has been named Elephant grade in the grading. Usually there are two seeds joining together to form the seed in a single cherry. This is the source of ears when the seeds part during handling. They are fragile that they break into smaller pieces during sorting and roasting |
| ML | Mbuni Light | small Screen 12 & 15 | These are the thinnest and smallest beans, that are mostly composed of bits and pieces of broken beans from the main grades. |
| T | Small Light beans | small Screen 10 & 14 | These are the thinnest and smallest beans, that are mostly composed of bits and pieces of broken beans from the main grades. |
| MH | Mbuni Heavy | Screen 15 & 17 | Natural processed coffees. large in size |