Several common coffee bean processing methods

We know that from coffee fruit to coffee beans, the process requires processing of raw beans. So what are the processing methods? What effect do these different coffee bean processing methods have on the flavor of coffee? Today, the editor will take you to explore it.

The processing of coffee beans is to remove the skin, pulp and pectin of the coffee fruit, take out the shelled beans (usually two are wrapped together, but there are also single ones), dry them to stabilize the properties of the beans, and grind off the shells before export.

01. Natural sun exposure

The cheapest, simplest and most traditional method of coffee bean processing, this method requires drying the whole coffee fruit. This processing method is still used in places such as Ethiopia and Brazil. The sun drying method allows the coffee fruit to dry naturally, so that the coffee beans can ripen naturally inside the fruit without being disturbed by the external environment.

Processing process:

1. Remove floating beans

Pour the coffee beans into a large tank. The underdeveloped and inferior beans will float to the surface, while the mature and plump fruits will sink to the bottom. At this time, remove the floating beans on the water surface, and the step of removing the floating beans is completed.

2. Sun exposure

The coffee cherries are evenly spread in the drying area and turned over several times a day. This process usually lasts about 2 to 3 weeks, depending on the local climate. When the moisture content of the coffee beans drops to 10 to 14%, the sun drying step is completed.

3. Remove the outer shell

After the sun-drying process is over, the outer layer of the coffee seeds has dried and hardened. At this time, a shelling machine is used to remove the outer shell to complete the sun-drying process.

Flavor: Coffee beans processed by the sun-drying method will have their own flavor amplified, with a rich body, strong flavor, and sweetness.

02. Water washing method

The water washing method is currently the most widely used processing method. The biggest difference from the sun drying method is that fermentation is used to remove the pectin layer.

Processing process:

1. Remove floating beans (same as sun drying method) Pour the coffee beans into a large water tank. The underdeveloped and inferior beans will float to the surface, while the mature and plump fruits will sink to the bottom. At this time, remove the floating beans on the water surface, and the step of removing floating beans is completed.

2. Remove the peel and pulp

The outer skin and pulp of the coffee fruit are removed through a pulping machine. (The pectin, endocarp and silverskin are left).

3. Fermentation

The purpose of this step is to remove the pectin by biological treatment. The coffee berries that have been processed by the pulp screener are placed in a fermentation tank for 16 to 36 hours, and the fermentation bacteria will dissolve the pectin.

4. Wash with water

After fermentation is completed and pectin is removed, the coffee beans are washed again because fermentation bacteria and impurities will remain on the coffee beans. In order to clean them thoroughly, this step consumes a lot of clean water.

5. Drying and removal of endocarp and silverskin

Usually, the coffee cherries are dried by machine (or sun-dried) to reduce the moisture content to 10-14%. Then, the remaining inner peel and silver skin are removed by a shelling machine to complete the processing.

Flavor: Usually, due to the fermentation process, the coffee beans usually have a bright sour and fruity aroma.

03Honey Processing Method

The honey treatment is a modified method of the sun drying method. The main difference between the honey treatment and the sun drying method is that the outer peel and pulp are removed before sun drying, and the pectin layer is retained and directly sun dried. Because the mucous membrane on the surface of the coffee beans is extremely sticky and the sugar content is extremely high, people usually call it "honey". During the honey treatment process, some or all of the "honey" will remain when the coffee is dried.

Processing process:

1. Remove floating beans (same as sun drying, this step may be omitted in some areas)

Pour the coffee beans into a large tank. The underdeveloped and inferior beans will float to the surface, while the mature and plump fruits will sink to the bottom. At this time, remove the floating beans on the water surface, and the step of removing the floating beans is completed.

2. Remove the peel and pulp (same as washing method):

The outer skin and pulp of the coffee fruit are removed through a pulping machine. (The pectin, endocarp and silverskin are left).

3. Sun exposure:

Spread the coffee beans with pectin in the drying area and expose them directly to the sun to reduce the moisture content to 10-14%.

4. Remove pectin and endocarp

The processing steps are completed by removing the pectin and endocarp using a special machine.

Flavor: Honey-processed coffee beans have a better flavor, with a balanced balance of sourness and sweetness. Because they are exposed to the sun, the aroma of the coffee beans themselves will be amplified and the taste will be rich.