BUF Nyarusiza 94 Hour Fermentation, Rwanda

A slightly different approach to our subscription this month. For the past two years we have pretty much dodged the Covid outbreak, but have eventually succumbed to it. It’s made roasting and shipping a little bit harder so we’ve reduced the information we’re sending out this month to a written format only.

This 100% red bourbon coffee was processed at Buf Café’s Nyarusiza washing station, at 1,743 metres above sea level in the south of Rwanda. 

Buf Café was founded in 2003 by Epiphanie Mukashyaka, a dynamic businesswoman and a source of inspiration to countless other female entrepreneurs in Rwanda’s coffee sector and beyond. Buf is now managed by Epiphanie and her son, Samuel Muhirwa, who is taking an increasingly active role in running and expanding the business. The title ‘Buf’ derives from ‘Bufundu’, the former name of the region in which its washing stations are located. 

Samuel and his mum, Epiphanie

Buf has very strong links with the local communities that supply it, providing jobs for 116 at Nyarusiza during peak harvest (May – June/July) and 9 permanent positions. A further 127 people are employed at Remera during harvest, with 10 permanent positions. At the end of each season Buf will share any surplus profits with both the cooperatives that it works with and its washing station managers. 

The majority of the small farmers in the area have an average of only 300 coffee trees (less than a quarter of a hectare) and use some of their land to cultivate other crops such as maize and beans to feed themselves and their families. Most of their income from the sale of coffee is used to take their children to school, pay for medical care and for investment in livestock such as a cow for milk, both for use in the home and for sale locally. 

Each producer selling their cherries to the Nyarusiza Washing Station, carefully handpick the cherries once ripe.  Lots are first separated by collection point (farmers usually hail from around 3 km distance from each collection point) and are also separated out by days. Upon delivery as cherry, the coffee receives a paper ‘ticket’ that follows the lot through all its processing. This ticket bears the date of harvest, the collection point name, and the grade (A1, A2 etc) of the coffee – for instance, if a coffee lot is called ‘Lot 1- 06/04 – A1’, this means it was the first lot processed on April 4 and the grade is A1. This simple but effective practice is a crucial tool in controlling quality and ensuring the traceability of lots. 


Upon delivery to the Washing Station, the cherries are spread evenly on raised tables to be sorted for quality purposes. 

After sorting, the cherries are covered by shade nets and submerged in water – 20L of water per 200kgs of cherry. Testing occurs regularly to ensure overfermentation does not occur. The coffee remains here for 94 hours to attain the ideal fermentation level. The fermented cherries are then moved to a mesh bed to initiate drying in the open sun until it reaches a humidity level of 10-11%. Once completely dried, the coffee is hulled at Kamonyi Dry Mill no more than 30 days later. 

BUF Nyarusiza 94 Hour Fermentation, Rwanda via @carvetiicoffee

Leave a Reply