Natural vs washed coffee: what changes in the cup

Natural and washed are two ways of getting a coffee seed out of its fruit. A washed coffee has the fruit taken off within a day of picking and dries as a bare seed, so it usually tastes clean and bright. A natural dries whole inside the cherry for weeks and usually comes out heavier and fruitier, with more that can go wrong along the way.

Both start in the same place. A ripe coffee cherry is a small fruit with two seeds inside, and each seed is wrapped in layers: the skin, the pulp, a sticky coat called mucilage, and a papery shell called parchment. Which of those layers come off, and when, settles a good part of the flavor before a roaster ever sees the coffee.

How washed coffee is made

1. Ripe cherries come in from the trees and are sorted, often in water, because damaged and underdeveloped fruit tends to float.
2. A pulping machine squeezes the seeds out of the skin and pulp, usually on the day of picking. On the family farms that happens the same afternoon.
3. The seeds, still slick with mucilage, sit in tanks while yeasts and bacteria break that layer down. A 2019 study from the Vrije Universiteit Brussel in Frontiers in Microbiology puts the usual time at 12 to 72 hours. Ours ferment for 36 hours in small tanks.
4. The loosened mucilage is washed off. We use spring water.
5. The clean parchment coffee dries on patios, on raised beds or in mechanical dryers. The FAO's guidelines on preventing mold in coffee set 12 percent moisture as the most dry parchment should hold. On our farms, getting there takes 18 to 21 days on raised beds.

Later a dry mill cracks off the parchment, and what is left is green coffee, ready to ship and roast.

How natural coffee is made

The natural, or dry, process is the older method, and it needs far less water and machinery.

1. Ripe cherries are sorted the same way.
2. The whole cherries are spread in a thin layer on raised beds, patios or tarps.
3. They are turned again and again so they dry evenly, because a thick or damp patch will mold or sour. In Sidama, the cherries for our Ethiopia dry on raised beds for up to three weeks and are turned by hand every hour.
4. When the fruit is dark brown, shriveled and hard, the mill takes off the dried skin, the pulp, the mucilage and the parchment in one pass. The FAO's limit for dried cherry is 13 percent moisture.

Naturals take longer to dry because a whole cherry holds far more water than a washed seed. The FAO guidelines note that cherry coffee sits through a lag of 1 to 3 days before it starts losing water quickly, against a day or less for washed parchment. Those extra days in the sun are where most of the risk lives.

What each process does to flavor

In a washed coffee you mostly taste the seed: the variety, the soil, the altitude, the rain that year, and then the roast. The acidity tends to read clean and defined, more like biting an apple than drinking juice, and the body is lighter. Most coffee from Colombia, Central America and Kenya is washed.

Naturals keep the fruit wrapped around the seed while it dries, and it shows. They usually have more body and riper, jammier fruit, sometimes with a winey edge. Ethiopian naturals are famous for blueberry, and our post on why Ethiopian coffee tastes like blueberry goes into that.

The same weeks in the fruit leave room for faults. A natural that dried too slowly or was piled too thick can taste of vinegar, compost or damp cardboard. Naturals vary more from lot to lot for that reason.

Why are naturals often sweeter? The usual answer is that sugar from the fruit soaks into the seed. Research on the seed itself adds another reason. A green coffee bean is still a living seed, and it starts the first steps of sprouting during processing, which burns sugar. Bytof and colleagues, writing in Annals of Botany in 2007, found that activity peaks about two days into wet processing but only about a week into dry processing. A 2006 study from the same group in European Food Research and Technology measured the result: washed beans held much less glucose and fructose than dry processed ones.

Fermentation happens in both methods, just in different places. In washed coffee it happens in a tank, under watch, for a set time. In a natural it happens inside each drying cherry. Our post on coffee fermentation covers both.

Our coffees as examples

We grow and sell both kinds. The light roast from Sidama is a natural, grown by Elena at 2,050 meters, with hints of blueberry, jasmine, peach. Our Colombia from La Cumbre and our Guatemala from El Mirador are both washed. The Colombia has hints of red cherry, panela, cacao nib, and the Guatemala hints of toasted almond and brown sugar, with orange at the end.

Tasting them side by side will show you the difference between a natural and a washed coffee, but it is not a clean test. The three also come from different countries and different trees, and they are roasted to different levels. If you want to taste process alone, look for a roaster selling a washed and a natural lot from the same farm and the same harvest, and brew both the same way on the same morning.

Where honey process fits

There is a middle way. Honey process coffee is pulped like a washed coffee but dried with some or all of the sticky mucilage still on the parchment, with no fermentation tank and no washing. It usually lands between the two in the cup: sweeter and rounder than washed, cleaner than most naturals. It is common in Costa Rica and the rest of Central America, and our guide to honey process coffee explains the yellow, red and black versions.

Which to choose

If you like a cup that is clear and bright, the kind where you can pick out lemon or green apple, start with washed coffees. If you like jam, ripe berries and a heavier body, try a natural. Most specialty bags print the process near the origin. Washed may also appear as wet process or fully washed, and natural as dry process or sun dried.