Coffee Processing Methods

Coffee processing refers to the method used to remove the outer layer of the coffee cherry (fruit) to reveal the inner seed, which is then dried and roasted to make the coffee beans we know and love. There are two main methods of coffee processing: wet processing and natural processing.

Natural processing

Natural processing, also known as dry processing, is an older method of coffee processing that is going through something of a revival and is becoming increasingly popular again. It involves leaving the cherry on the seed to dry in the sun, either on raised beds or on the ground. The dried cherry is then removed manually or using a machine.

Advantages of natural processing

Advantages of natural processing include a unique, fruity flavour and a lower environmental impact. The drying process also removes any defects or impurities in the coffee. Natural processed coffee is also less likely to spoil during storage and transportation, as the dried cherry acts as a natural barrier against bacteria and mold.

Disadvantages of natural processing

Disadvantages of natural processing include a lower yield of coffee beans and a higher risk of spoilage. The coffee can also be affected by weather conditions, such as rain, which can negatively impact the flavour. Additionally, the process is labor-intensive and requires more space, which can be costly.

Coffee processing sieves and racks
processing coffee beans

Wet (washed) Processing

Wet processing, also known as washed coffee, is the most common method of coffee processing. It involves removing the outer layer of the cherry using water. The cherries are first pulped to remove the outer skin and fruit, leaving just the seed. The seed is then fermented in water to remove the remaining mucilage, which is the sticky layer surrounding the seed. The seed is then rinsed and dried, either in the sun or using mechanical dryers.

Advantages of wet processing

Advantages of wet processing include a consistent, clean taste and a higher yield of coffee beans. The fermentation process also helps to remove any defects or impurities in the coffee. Wet processed coffee is also less likely to spoil during storage and transportation, as the water removes any bacteria or mold that may be present.

Disdvantages of wet processing

Disadvantages of wet processing include the need for large amounts of water and the potential for pollution of nearby water sources. The process is also more labor-intensive and requires more equipment, which can be costly. Additionally, the use of water can lead to the spread of disease among coffee plants, which can decrease yield and quality.

Each processing method has its place

Both wet processing and natural processing have their own advantages and disadvantages. Wet processing is the most common method for producing coffee, it results in a consistent, clean taste and a higher yield of coffee beans. However, it requires large amounts of water and has a potential for pollution of nearby water sources.

On the other hand, natural processing is becoming increasingly popular, it can result in a unique, fruity flavour and a lower environmental impact. However, it has a lower yield of coffee beans and a higher risk of spoilage. Each method is unique and its choice depends on the preference of the coffee producer and the consumer.

By Pat McArdle