Washed or natural?

By Oscar García | |

Washed or natural? Two approaches to heirloom Ethiopian coffee

One of the most common questions (and misperceptions) I run into as a Green Coffee Buyer is what is the difference between washed and natural process coffee. And how does this different approach to processing affect the flavor of the coffee?

Right now, we have the very rare opportunity of offering both washed and natural process coffee from one of the world’s greatest coffee producing regions, Yirgacheffe in Ethiopia. Both coffees are grown and harvested in the same soil, on the same plants, by the same farmers. It’s one of the few times when you can control every single other variable besides the processing. This means you can finally taste the difference for yourself! You can try Dumerso Washed Coffee here. And Dumerso Natural Coffee here.

Can you tell which is the washed vs. natural processed coffee?

An Ethiopian Woman Leader

Before delving into the coffee processing, a few words about where this coffee comes from and how it gets to you. This remarkable coffee is a collaborative effort by the small community of Dumerso, located in Ethiopia’s renowned Yirgacheffe region, known worldwide for its high quality coffee. About 700 small family farmers grow and harvest coffee cherries in this area.

But drying and sorting the coffee requires more space and equipment than most people have available in their small family plots. In 2010, Hirut (aka Beti) bought what had been a defunct washing station and warehouse building. It had been built in 1998 but never operated. She upgraded it and has been running it since 2013.

During the harvest season, the Dumerso washing station now provides employment for nearly 400 people from the community. Beti worked hard to acquire a coffee export license, once Ethiopia started allowing direct export licenses in 2017. This allows Seattle Coffee Works to get fresh crop Ethiopian coffee to the US months ahead of other coffee importers and roasters.

It is exciting to see the success of Dumerso, and especially inspiring to see a woman spearheading this incredibly challenging effort. In an industry that has too few women leaders, Beti is a real-life role model!

Hirut "Beti" Birhanu with her children and community members with the washed green coffee on raised beds.

Natural Process

For the natural process coffee, farmers bring the freshly harvested coffee cherries to the station by around 6 pm each day. The coffee is spread out on raised drying beds, where air can circulate around the cherries. The fruit peel and pulp remains on the cherries as they dry over the course of 15 days. While on the drying beds the coffee is sorted to eliminate any unripe or overripe cherries and unwanted material. This meticulous work is done by hand, mostly by local women.

Once the coffee has dried to the appropriate moisture level, it is moved to a warehouse. The coffee beans are kept covered with their skins intact to preserve quality. The skins are removed at the “dry mill” in Yirgacheffe and in Ethiopia’s capital Addis Ababa graded, sorted and handpicked once more, just before being bagged for export.

Washed Process

For the washed process coffee, the coffee pulp is removed by mashing, then fermented in tanks for 36 to 48 hours to remove the mucilage on the parchment (the time depends on the ambient temperature if it is very cold the hours increase and if it is hot the hours decrease). The coffee beans are separated according to quality using the water floating method. A final manual rinse, agitated with wood paddles, finishes off the washing process. The coffee then goes into a soaking tank for 12 hours.

Finally, the coffee is spread out on raised beds to a maximum thickness of 3 cm to dry for 9 to 11 days. Natural ventilation and sunlight bring the moisture level to 11 to 12%.

After it has dried to the right moisture level, the coffee beans are kept covered in their parchment layer in the warehouse to preserve their quality. In Addis Ababa, it undergoes dry-milling, grading, sorting and handpicking, before being bagged for export.

If you were to walk by the Dumerso Washing Station during harvest season, you would immediately notice the difference between natural and washed process coffees. Some drying beds have dark red to black cherries on them - those are the natural process coffees drying in their skin. Other beds have light green to gold coffee seeds - those are the washed process coffees. In all other respects, the coffees are the same.

Both processes have advantages and disadvantages. The washed process requires more equipment and water. The natural process requires more time and drying space. Both require a huge dose of attention and expertise.

Tasting starts with your eyes - note subtle differences in the coffee beans. These beans are green because they have not been roasted yet.

A Controlled Experiment You Can Do at Home

You can run your own tasting experiment by making a cup of each of these coffees:

Dumerso Natural

Dumerso Washed

Once you have the coffees in hand, take a moment to observe the whole beans and notice any differences. Then weigh out and grind a small batch of each beans separately. Pour the grounds onto two saucers, where you can observe and smell the aromas and note any differences.

Next, make two cups of coffee. We recommend using an Aeropress if possible, since this speedy device allows you to make two coffees in a row very quickly. Another good possibility is a Clever. Sniff the coffees in separate cups, and jot down any observations. Then take a sip while the coffee is hot, and again note any sensations as well as flavors. Keep sipping as the coffee cools, and you may notice the flavor changes with the temperature.

Once you've tried these two coffees side-by-side, please let us, and the community of Dumerso know what you think! We love to hear from you at service@seattlecoffeeworks.com