Coffee processing

Harvesting the coffee cherries

Selective harvest
In many growing regions, selective hand-harvesting is preferred. Trained workers pick only ripe cherries, which are identifiable by their red or yellow color. Selective harvesting requires multiple passes through the orchard, as not all cherries ripen at the same time. This method ensures that only the optimally ripe cherries are harvested, resulting in a higher quality final product. Workers use special baskets or sacks worn around their waists to collect the picked cherries. After each pass, the cherries are immediately taken for processing to preserve their freshness and quality.

Mechanical harvesting
In regions with flatter terrain and large plantations, mechanical harvesting can be an efficient alternative. Machines drive over the coffee rows and shake the cherries from the trees. This method is faster and more cost-effective, but can be less selective. Therefore, the harvested cherries must be sorted afterward to remove unripe or overripe fruit. Mechanical harvesting is particularly suitable for Robusta coffee or in regions where labor shortages are a problem.

Semi-mechanical harvesting
Semi-mechanized coffee harvesting combines modern technology with traditional manual labor to make the harvesting process more efficient. Machines assist harvesters with tasks such as beating and collecting the coffee cherries, while experienced workers continue to selectively harvest ripe fruit. This reduces workload while ensuring the quality of the coffee. This method makes it possible to strike a balance between productivity and maintaining traditional harvesting techniques in challenging terrain and under varying climatic conditions.

Comparison and quality impacts
While mechanical harvesting is impressive for its efficiency, manual selective harvesting offers the advantage of more precise cherry selection. This care directly impacts the quality of the coffee. Only optimally ripe cherries produce beans with the best aromas and flavor profiles. Manual harvesting is more labor-intensive and expensive, but results in a final product that meets the high standards of the specialty coffee industry.

Processing the coffee cherries

Washed Process
Wet processing is one of the most common methods for processing coffee cherries and is often used in regions with sufficient water resources.

1. Pulping: After harvesting, the freshly picked cherries are pulped, meaning the pulp is mechanically removed to expose the beans. This is done in special pulping machines that open the cherries by grinding or squeezing.
2. Fermentation: The depulped beans are then transferred to fermentation tanks, where they remain for 12 to 48 hours. During this time, natural fermentation breaks down any remaining pulp. The duration of fermentation depends on the environmental conditions and the desired flavor development. Careful monitoring is necessary to avoid overfermentation, which can lead to undesirable flavors.
3. Washing: After fermentation, the beans are thoroughly washed to remove any remaining pulp. This is done in washing tunnels or mechanical washing machines. Washing ensures the beans are clean and ready for drying.
4. Drying: The washed beans are dried in the sun or in mechanical dryers. Sun drying involves spreading the beans out on large drying surfaces and turning them regularly to ensure even drying. This process takes several days to weeks until the beans reach a moisture content of approximately 10-12%. Mechanical dryers can accelerate the drying process and are particularly useful in regions with changeable weather.

Dry processing (natural process)
Dry processing, also known as the natural method, is the oldest form of
Coffee processing and is used in regions with limited access to water.

1. Direct drying: In this method, the coffee cherries are dried in the sun immediately after harvest. The cherries are spread out on large drying areas or on raised drying beds to ensure good air circulation.
2. Turn regularly: To ensure even drying and
   To prevent mold growth, the cherries must be turned regularly. This is done manually or with the help of machines.
3. Drying time: The drying process can take several weeks, depending on weather conditions. The cherries must be completely dry before they can be processed further.
4. Shelling: Once the cherries are completely dry, they are shelled mechanically or manually to separate the beans from the dried fruit skin. This method often imparts a bold, fruity flavor to the coffee.

Semi-washed processing (Honey Process)
Semi-washed processing is an intermediate method that combines elements of wet and dry processing and is often used in Central and South America.

1. Partial pulping: This method involves partially removing the pulp, leaving a portion of the mucilage (slime layer) on the beans. This step is similar to pulping in wet processing, but less thorough.
2. Drying : The partially pulped beans are then dried in the sun. The remaining mucilage ferments slightly during drying, giving the coffee a sweeter and fruitier flavor.
3. Regular turning: To ensure even drying, the beans must be turned regularly. The drying process takes several days to weeks until the beans reach their optimal moisture content.
4. Shelling and polishing: After drying, the beans are shelled to remove any remaining fruit residue. They are then polished to ensure a smooth surface.