Coffee Processing Basics: Washed

Tuesday, 4 February, 2020

So what does it mean when you see 'Washed' coffee on a bag of beans you purchase? A basic run through for aspiring coffee geeks!

Washed is the process of removing the fruity outer layer of the coffee cherry to leave the seeds that will become what we know as coffee beans.

Crazy right?! We always strive to keep coffee consumers informed and inspired by just how much effort goes in to their daily cup of coffee and this processing method at farm level is used worldwide. 

Ripe cherries are picked from coffee trees during harvest season. A lot of small-holder farmers tend to belong to co-operatives, which means a central Washing Station is utilised to process the cherries. A washing station requires machinery, space, water supply and other infrastructure. Estate farms will have their own dedicated processing station.

Cherries picked are weighed so each picker/small holder can be remunerated. Then they are loaded into the shoot ready to go through the depulper.

They are first put in a tank of water for cleaning and density sorting. Ripe fruit sinks to the bottom and unripe, over-ripe and foreign matter floats to the top and is removed. The ripe fruit is then routed through a depulping machine.

A coffee depulper is a large machine that strips the fleshy fruit from the seeds, by squishing them against each other and pinching the beans out of the cherry leaving them sheathed in the mucilage - a sugary, sticky layer of goo.

The seeds are then soaked in fermentation tanks and pushed through channels as seen below to remove this mucilage from the parchment that holds the seeds together.

The washed seeds are then laid out to dry in the sun. This can be on raised drying beds, as seen below in Ethiopia, or on concrete patios. 

Got something to say? Then leave a comment!