Inge is one of the owners of Back to Black coffee. Because she visited Ethiopia last June, she saw the wet process of specialty coffee on the spot with her own eyes. In this blog she will explain exactly how the process work.
Besides water, coffee is the world’s most consumed drink and it’s produced in many countries. There are many different processes to make a coffeeberry into a green coffee bean. Even though in different countries the same type of processes are used, it can be done in a slightly different way. Within a country the processes can differ even between washing stations or dry mills. To keep it simple, I will explain the wet process of specialty coffee at Bodgi washing station in Ethiopia. The washing station is located in the municipality Kochere, zone Gedeo and region Oromia in the south of Ethiopia.
The coffee plant
It all starts with the coffee plant. There are many different kinds of plants and they have different varieties. Bodgi washing station uses Arabica plants of which different varieties can be processed. Almost every coffee from Ethiopia has the Heiloom variety. Bodgi washing station works with 2000 coffee plantations, so it’s hard to designate every variety of all the coffee. A cup of coffee can easily have 4 different kinds of varieties.
Bodgi uses different trading venues to buy bags with coffeeberries from the farmers. Buyers don’t differentiate bags with ripe or unripe berries. The farmers who sell the berries will get the same amount of money for a bag with a mix of ripe and unripe berries, as when they only sell ripe berries. This is such a waste, so I hope that it will change in the future.
During the next step the coffeeberries will be put into a large funnel and will end up in a machine, which is called the pulper. The machine has rotating blades to open the berries and remove the skin. The skins of the berries will be separated, so it can be used to fertilize the farmland. After pulping, the berries that are lighter in weight will be separated from the heavy ones by using a net in the sluice. The berries are going overhead when the skin is still attached to the berry or when they are too light due to, for example, underdevelopment.
The berries that are pulped well, end up in several fermentation tanks. It needs to ferment for circa 48 hours. The type of climate affects the exact duration of the fermentation. The last layer of the seed, the shell or parchment, will loosen up properly. The remaining seed is in fact the green coffee bean, the one it’s all about.
After the fermentation, the berries will end up in a kind of long sluice of cement. The berries are pushed through the water over and over again. That’s how they wash of the mucus (mucilage) and the remaining skin of the berries. The washing process is done when the shell starts to feel rough.
The cement sluice is locked by a kind of a wooden dam, which is made of several shelves. When the top shelf is removed, the lighter parchment coffee will flush into the tanks. The coffee will be added to the berries that were too light in weight. The heavier ones will stay on the bottom of the tank and rinse away when the entire dam is removed. This is the first class coffee. The coffee will go to a patio where it will dry for over 6 hours and thereafter it will be brought to the drying beds.
Bodgi is located in the mountains at 1750 meters high and has a continental climate. It can be very hot during the day, but in the evening it will cool down extremely. Bodgi washing station has excellent drying beds for the specialty coffee in a huge white tent. The tent has a cement floor to keep the moisture out of the coffee. On both sides there are beds arranged in long rows which are stacked as bunk beds, and each one is filled up to 6 centimetres high. Instead of a slatted bed base with a mattress, they use a kind of sieve to make sure the beans will not fall through it. This causes an airflow along the coffee. For the same reason they have fans on the ceiling.
The tent can be opened up semi automatically, in order to dry the coffee through the sun during the day and have the possibility to close it in the evening. To continue the drying process through the nights, they use a heat gun. There are women who are loosening the coffee for 24 hours to prevent uncontrolled fermentation (decompose), which can appear between the beans. The quick dry will last for 7 days and the slow dry will take 13 till 14 days. When a quick dry is used, there will be a smaller chance to get uncontrolled fermentation, but with the slow dry technique the core of the bean will be drier. By cupping or grading the coffee it ensures an even higher grading and quality of the coffee.
After the process, the coffee will be packed and brought to a dry mill for the last process. In this case the coffee will be brought to a dry mill close to the capital city Addis Ababa. The next step is to ship the coffee beans in large sea containers to several roasteries all around the world. Next time I will tell you more about this process in part 2.