Washed coffees
Processing methods,
Washed Coffees
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I want to be clear, but this may someway be diffused and perhaps complicated to understand, the meaning of washed coffees - as most of the washed coffees are more or less being fermented/soaked in water for x hours.
We have a long tradition defining things in this industry by culture and/or traditions - not being clear on whatever methodology used - and what the expected outcome of this method should end up with.
When I started searching and sourcing coffees around the world in 2008, a lot of traditions were simply passed on from one farm manager to another as it used to be in the old days. Often farmers crossed the border from adjacent countries, as knowledge was passed by or simply hired to do some farming.
A lot depended on existing or availability of water and resources to process coffees at the washing stations.
Often the coffee was roasted dark, the berries were picked with uneven ripeness, different varieties were mixed, different lots were mixed. Even coffees from different regions were just mixed together.
Today the coffee scene has changed. Changed into something beautiful, not using phrases as burned asfalt, dark and bitter or overfermented taste in coffee.
We speak of attributes in coffee as the winemakers do. The Coffee scene has found its own track that draws so many parallels to the winemakers vocabulary.
To understand the concept of washed coffee we need to look a few years back of different definitions of fully washed coffees.
Some varietals are more acid than others which makes it complex to understand one processing method from another. To narrow it down to a digestable mouthfeel I will try to direct my experience with washed coffees.
Simple, the coffee skin is removed using water. But the process afterwards makes the difference.
F.W/Fully washed coffees
When the coffee skin is pealed of between two rollerblades using water the coffee passes on directly on to drying beds/or concretes.
- if the coffee passes further to "A Tank"cement concrete and soaked in water afterwards - its still called washed coffee. In reality we should use the term "fermented coffee" - but we dont as an over fermented coffee used to be a defect in the coffee industry. And this term is hard to change overnight.
The Kenyan Method:
Pulped parchment is placed in a fermentation tank and allowed to ferment overnight. At 8AM the next morning, the fermented parchment is washed one time and allowed to ferment for another 24 hours. The following morning the parchment is washed completely and allowed to soak in spring water for 24 more hours and then it is dried. Total time in proces is 2.5 days.
The Burundi Method:
Pulped parchment is placed in a fermentation tank for 12 hours then washed. Water is then placed with the parchment and allowed to ‘ferment’ for another 12 hours. Afterwards, it is drained and then more water is added for ‘underwater fermentation’ another 12 hours.
The Rwandan Method:
Pulped parchment is placed in the fermentation tank and mixed hourly to evenly distribute the inoculums. The parchment is then ‘tested’ for readiness every hour from 12 hours on. Once a sample displays a ‘clean, non-slimy feel’, the parchment is washed 5-6 times and is ready for drying.
The Rwandan Method 2
With spring water soaking. The above process with the additional step of soaking in spring water for 12 hours once it has been fermented and washed.
When you peal off the skin and remove the mucilage/natural sugars inside the coffee berry you also lower the sweetness in the coffee. Some coffees are just better when you maintain the mucilage intact - and some are better off.
Expected outcome
/more acidity/brighter flavors/distinct fruitiness/less bodied/pleasent sweetness/tea-a-like flavors.
Today more efficient measurements used compared to the stick method mentioned above - the measurements are more precise and documented nowadays.
Washed coffees can be soaked in water, from 2 hours uptil 72 hours depending on the outcome and the varieties characteristics. As the coffee is being soaked in water, time is equal to fermentation as the sugar breaks down to simpler sugar molecules
We did a test to see the outcome
Tank 1: 24 hours
Ph 4.42
Brix 13.5
Temp 20
Tank 2: 48 hours
Ph 4,12
Brix 11,5
Temp 20
Day three - the coffee started to produce alcohol, and if you understand to control this you can achieve Coffee that reminds of Rom a-like-cinnamon flavors and lactic acid.
A very popular type of fermentation among baristas now days - anaerobic fermentation, also known as carbonic maceration.
I will get back to this subject in another article. As I want to highlight the effect on washed coffee.