A simple question to many but a fundamental choice for producers when processing their coffee. The processing stage is far from simple; the complexity of the flavours that result ultimately shape your coffee experience. The technology and skills required in the wash process are at more expense, but it essentially moulds the array flavours. As you will see, what goes into making speciality coffee is certainly drawn out in the final brew.
The Washed Process
The washed process is the longer and more expensive method of processing coffee cherries. When compared to the natural method of processing coffee, the washed method involves more stages and more machinery. These increases in cost and time means washed coffee tends to be used for speciality coffee as opposed to commodity.
When the cherries are picked, they have an outer skin which is stripped down to the coffee bean before drying. Most of the fruit flesh is stripped using a machine called a depulper which makes it a more expensive process. The beans are then moved to a clean tank of water where the rest of the flesh is broken down through the process of fermentation. Coffee beans are soaked in the water to ferment for a period of time ranging from 24-36 hours, depending on the producer. Fermentation time must be perfected because leaving the coffee for too long can allow for poor flavours to infect the beans.
The main step taken during the natural process is not taken until now in the washed process; drying the beans. This is one reason why this process is used for high quality speciality coffee as opposed to the natural process. Drying the stripped beans rather than the cherries significantly reduces the risk of poor drying. All of the sticky flesh has been removed before drying so the beans can easily be separated and graded into high or poor quality. The beans are either dried in mechanical dryers - again adding to the cost but also to the quality - or spread out on patios and dried by the sun.
What goes into the washed process can really be tasted as it is drawn out. Washed coffees are known for being of a distinctly high quality as they produce a much cleaner and brighter tasting brew. If you prefer a fruity and slightly acidic flavour, washed coffee is for you, especially if you want the highest quality beans.
The Natural Process
The natural process is the oldest method of processing the coffee cherries, which is why it is regarded as the classic technique. It is also referred to as the dry process, unsurprisingly because little or no water is used, hence the word ‘unwashed’.
In places such as Ethiopia and parts of Brazil and Indonesia, water access is extremely scarce. They also boast consistent strong sunlight which aids proper drying of the cherries. For speciality producers in these countries, the unwashed process is the only method of processing available. So, in other places where water access is not an issue, this method is generally only used for very low quality commodity coffee.
Once the cherries have been picked, they are cleaned and then spread out in a thin layer to be dried in the sun. Some producers choose to lay the cherries on brick patios, a method also used in the washed coffee process, others use raised drying tables which allow better airflow and a more even dry. Those that dry on patios must rake the cherries continuously to promote drying. As well as raking, the cherries must be turned regularly to avoid mould, rotting and fermentation. Whatever producers choose to do, they require a dedicated workforce, meaning an investment of both time and money.
Both processes require the cherries to be laid to dry for up to four weeks in order to achieve the ideal moisture content of roughly 11%. When the desired moisture content is reached, the outer husk of the skin and dried fruit are mechanically removed, also known as hulling. The raw coffee is then graded, sorted and stored, ready for exportation.
Not washing the beans doesn’t require as much skill as the washed process meaning it is a much easier process. The natural process is widely used among coffee producers around the world because of its simplicity. The lack of skill required also means it is a more economically viable process so is used more by commodity coffee producers. It is also known for producing bold, heavier, sweet and smooth coffees.
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Written by Katie Humphrey