We know that coffee is slowly transformed from coffee cherries into coffee beans, but in this process, we need to process the green coffee beans. So how do we process these green coffee beans? What is the impact of processing green coffee beans on coffee? Today I will take you to find out.

Natural sun tanning

The cheapest and simplest traditional coffee bean processing method requires drying the entire coffee fruit. To date, regions such as Ethiopia and Brazil are still using this traditional method to process coffee beans. The sun drying method is a method of drying the coffee fruit naturally by exposing it to the sun, allowing the coffee beans to mature naturally inside the fruit. This method prevents the coffee beans from being affected by the external environment.

1. Remove inferior beans

Put the coffee beans into a large tank of water. The underdeveloped and inferior beans will float on the surface, while the mature and plump ones will sink to the bottom of the water. You can then remove the coffee cherries floating on the surface.

2. Sun exposure

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

3. Remove the outer shell

After the sun-drying process is over, the shell of the coffee fruit has dried and hardened. At this time, the shell can be removed using a shelling machine to complete the sun-drying process.

Flavor: Coffee beans processed by the sun drying method will amplify their own flavor. Generally, the alcohol content will be stronger, the flavor will be strong, and it will also emit a light sweetness.

Water washing method

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

1. Remove inferior beans (same as sun drying method)

Put the coffee beans into a large tank of water. The underdeveloped and inferior beans will float on the surface, while the mature and plump ones will sink to the bottom of the water. You can then remove the coffee cherries floating on the surface.

2. Remove the peel and pulp

The coffee cherries are passed through a pulper to remove the outer skin and pulp of the coffee cherries. (The pectin, inner skin and silver skin are left behind).

3. Fermentation

This step uses biological treatment to remove pectin. 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. Washing

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

5. Drying and removal of endocarp, silver skin,

Generally, coffee cherries are dried by machine (or sun-dried) to reduce the moisture content to 10-14%. Then, a hulling machine is used to remove the remaining inner peel and silver skin, thus completing the processing.

Flavor: Due to fermentation, coffee beans generally have a bright sour and fruity aroma.

​Dense processing method

The honey treatment is a modified version of the natural drying method. The main difference between the honey treatment and the natural drying method is that the outer peel and pulp are removed before the natural drying, and the pectin layer is retained before direct natural drying. 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 on the coffee when it is dried.

1. Remove inferior beans (same as sun drying, but this step is omitted in some areas)

Put the coffee beans into a large tank of water. The underdeveloped and inferior beans will float on the surface, while the mature and plump ones will sink to the bottom of the water. You can then remove the coffee cherries floating on the surface.

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

The coffee cherries are passed through a pulper to remove the outer skin and pulp of the coffee cherries. (The pectin, inner skin and silver skin are left behind).

3. Sun exposure

Spread the coffee beans with pectin in the sun drying area to reduce the moisture content of the coffee beans to 10-14%.

4. Remove pectin and endocarp

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

Flavor: Honey-processed coffee beans have an excellent flavor, with a good balance between sourness and sweetness. Because they are exposed to the sun, the aroma of the coffee beans themselves is amplified and the taste is rich.