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FROM THE CHERRY TO THE GREEN COFFEE

There are three methods for transforming the coffee cherries into beans which have a direct impact on the cost and quality of a coffee.  These methods involve removing the waste from the crop and taking off the various outer layers of the beans. This is how the green coffee is obtained, which is the generic term given to coffee after it is processed and before it is roasted.  The wet method favoured by   Nespresso, which requires more investment and care, results in coffee with a more complex aromatic profile.

The wet method

Wet processed coffee is sometimes referred to as "washed" coffee. These are generally high quality Arabica coffees.

• Washed Arabicas are also known as "Milds".
• Usually the wet method is used for hand-picked fruit and the dry method for other harvesting means.
• Wet processing enhances a coffee's aromatic notes and reduces bitterness.

Complex and costly processing is only used for ripe fruit in order to obtain an incomparable raw material.

Steeping takes place less than 24 hours after harvesting. Find out more

• The beans are submerged in a water bath for 16 to 36 hours until they have expanded and softened.

Pulp removal is carried out by machine. 

• A machine separates the bean from the pulp using friction.

Fermentation can take between 12 and 36 hours. Find out more (fenêtre

• The beans are placed into concrete water tanks.
• The fermentation process breaks down any viscous substances remaining on the beans after depulping.

Washing allows any remaining pulp to be removed and the ripest beans to be selected. 

• The coffee beans are forced against a water current to free them from any remaining impurities.
• The ripest beans are also the heaviest beans. They sink to the bottom of the water. Sorters can therefore take them out easily.

The beans are then naturally dried in the sun for up to three weeks. 

• At this stage the coffee is known as "parchment coffee" It is dried in the sun either on huge racks on rails that can quickly be closed in case of rain or spread over large tables made of fine-mesh wire netting.

The remaining outer layers of the bean are then removed by the hulling process. Find out more

• This operation is performed by a friction huller, roller huller or impact huller.
• This enables the green coffee to be obtained, ready to be put into sacks and exported to the coffee merchants.

The dry method
Coffees processed with the dry method are referred to as "unwashed" or "Natural" coffees. Find out more

• Dry processing, which often uses ovens, is a much quicker, easier and less expensive method than wet processing.

The dry method consists of drying the cherries on large surfaces in the fresh air for three weeks to a month.

• With this method the pulp isn't removed before drying.
• The coffee cherries left to dry are regularly turned over using a rake to prevent their fermentation. This technique leads to a loss of aromas and the migration of sugary substances from the pulp into the bean. The result in the cup is milder and less aromatic than the wet method.
• The dry cherries are then hulled: the outer layers of the coffee beans are then removed.

The coffee beans are then sorted by size, shape and density.

• It is during this grading operation that any beans that are deemed to be defective can be removed either manually or mechanically.
• In addition to screens and strainers, the human hand is still the most accurate method of sorting.

The semi-dry method
An intermediate between the wet and dry methods, this solution, if carried out effectively, balances the body and acidity of the coffee. Find out more

• The ripe cherries are separated from the unripe cherries by using a small amount of water.
• The pulp is then removed mechanically.
• Lastly, the coffee beans, still covered with mucilage are dried in "suspended beds" to avoid any contamination with the ground.
View the film about the processing of coffee cherries.