Thiriku AB (Kenya)
Terroir Best Lot
QUALITY SCORE: 88.00
Blackcurrant / Grapefruit / Lime / Plum
Suggested for espresso and filter
when we roast
We freshly roast to order all coffees on Monday, Wednesday and Friday (excluding national holidays), and ship the same day! Cut-off time is 11:59pm (UTC+1) of the day before the roast day. *We only ship whole beans*
- Quality Score
- Several small farmers
- 1880-1970 masl
- Kenya Washed (post soak)
- Arabica cultivar
- Picked in
- January 2022
- Arrived in
- September 2022
- Shipped in
- Jute + GrainPro
- Roast profile by
- Rubens Gardelli
- Roasted on
- Customised roaster
THE STORY BEHIND
Coffee industry in Kenya has been experiencing some turmoil in the recent years: farmers have been disappointed by very low profits and corruption of the cooperative managements officials, and the productivity of cultivation has been decreasing.
Farmers in the area where Thiriku washing station is now located started replacing coffee with other lucrative crops for these and possibly other reasons. However, once the dynamics in the co-op society shifted with the entry of a new importer, many farmers revived coffee cultivation thanks to the promise of stable baseline income each season. In exchange, the farmers have committed to producing the coffee of highest quality and improving their agricultural practices in close cooperation with the local agronomist, Bernard Gichimu.
It is thanks to these improved cooperation between the farmers and the cooperative that Thiriku has become a special washing station, consistently producing some of the best tasting lots in the country.
SL28 was bred by Scott Laboratories in 1931 from Tanganyika D.R. It has become very popular throughout Kenya and is recognised as a variety of exceptional cup quality. It has wide leaves with coppery tips, and the beans are wide. At the same time, the productivity of SL28 is comparatively low. Though there is no sufficient proof, some sources claim that Scott Labs crossed mutations of French Mission, Mocha and Yemen Typica to produce SL 28. Whatever the exact genetic composition, their original goal almost certainly was to create a plant with high quality, reasonable productivity and great drought resistance.
THE FERMENTATION PROCESS
Washed coffees showcase solely the bean. They let you taste you what’s on the inside, not the outside. Washed coffees depend almost 100% on the bean having absorbed enough natural sugars and nutrients during its growing cycle. This means the varietal, soil, weather, ripeness, fermentation, washing, and drying are absolutely key.
Washed coffees reflect both the science of growing the perfect coffee bean and the fact that farmers are an integral part of crafting the taste of a coffee bean. When looking at washed coffees, it becomes apparent that the country of origin and environmental conditions play a vital role in adding to the flavour.
Kenyan coffees are most often processed using a method called ‘double fermentation’, which is a variation of the washed processing method.
Almost all producers across Kenya only use this method, considered the best practice by many.
In the double fermentation processing method, farmers depulp the cherries immediately after harvest and place the mucilage-coated seeds in fermentation tanks, keeping the contact with water at the minimum, for 12 to 24 hours depending on the rate of fermentation.
The fermentation helps break down the mucilage, making it easier to remove, but also helps develop the mucilage’s latent fruit properties, imparting some of those properties into the coffee seed.
At this first stage, the fermentation is allowed to continue until most of the mucilage gets separated from the seed. The coffee is then flushed from the tanks into water channels, where the agitation helps to rinse and remove the loose mucilage, stopping the fermentation process. Seeds that are low density ‘floaters’ are also scooped off at this stage of the process, - this is one of many steps ensuring the consistently high quality of Kenyan coffee.
After the coffee has been cleaned, step one is repeated, and the coffee is left soaking in a secondary fermentation tank for other 12 to 24 hours. The fermentation gets restarted, but this time less sugar and fruit material is available. When this second stage is over, the coffee is once again run through water channels where any final residual mucilage is removed.
The coffee is then separated in lots, and the various lots are moved into their own water tanks where the coffees are soaked for additional 24 hours. Since the mucilage has been completely removed, and the coffee is soaking in significantly more water, it’s assumed that enzymatic activity in the coffee increases in this soaking tank, resulting in a strengthening of the amino acids and proteins present in the coffees.
The soaked seeds are then taken out and placed on raised drying beds and spread to a depth of a couple of inches. The idea is to initially dry the coffee rapidly to drop the moisture content and reduce the risk of rotting. After this initial fast drying period, the coffee is heaped into 6 inch deep mounds and moves into a longer, slower stretch of drying to encourage long term quality of green beans. How long the coffee remains on the raised beds can vary greatly depending on temperature and weather but it needs to be constantly turned during this period to achieve even drying. Once the moisture of the coffee reaches around 11-12%, this essentially concludes the processing of Kenyan coffee. They are finally dry hulled, graded and prepped for export.