Kenya’s washing stations use a processing method found almost nowhere else, and it is a substantial part of why Kenyan coffee tastes as it does.
The stages
- Pulp the cherries.
- Ferment in tanks, typically 12 to 24 hours.
- Wash the mucilage off in channels.
- Soak the parchment coffee in clean water for a further 12 to 24 hours.
- Dry slowly on raised beds, often for two weeks.
The fourth stage is the unusual one.
What the soak does
The mechanism is debated. The most common explanation is that a long clean-water soak allows further enzymatic activity without the microbial fermentation that produces funk, developing acidity while keeping the cup exceptionally clean.
Whatever the mechanism, the result is Kenya’s characteristic combination of intense acidity and remarkable clarity.
The cost
Water, in enormous quantity, in a country where water is not abundant. That has driven investment in recycling systems at many factories.
Why it is not copied more
It requires infrastructure, water and time. Several producers elsewhere have experimented with it, generally without reproducing the Kenyan result — which suggests soil, variety and altitude are doing part of the work.
Brewing it
Filter, light roast, hot water, fine grind.