Once the cherries reach the mill, the coffee is washed with water from the Kagondo River. The water is pumped via a diesel engine into reservoir tanks. After the cherries are pulped, the coffee is placed in large tanks to soak in water and ferment. This allows for the breakdown of the exterior mucilage, normally lasting overnight. The coffee is then spread evenly on raised tables to dry in the open sun until a targeted moisture content is reached.
Producers and the Factory collectively value sustainability, and various projects have been enacted to reduce environmental impact. Wastewater used for processing is carefully placed into soak pits to seep back into the soil without polluting the local drinking source.
Ruiru 11 is used by all producers contributing cherries to the Kayu Factory. This varietal was developed by the Coffee Research Institute in 1985 to combat the spreading Coffee Leaf Rust and Coffee Berry Disease.
Despite its proximity to the birthplace of coffee, Ethiopia, coffee growing was introduced in Kenya relatively late – by Scottish missionaries, initially, and then commercially around 1900. Despite the late start, today, it is a country renowned for having some of the best coffees in the world. Nonetheless, Kenya’s coffee sector faces challenges for the future, and low global prices combined with climate change and population growth have diminished the country’s output over the last decade.