Washed, natural and honey coffee: processing methods explained

The short answer

• Washed: the skin and fruit are removed and the beans are fermented and washed clean before drying.
• Natural (dry processed): the whole cherry is dried with the fruit still on.
• Honey or pulped natural: the skin is removed but some or all of the sticky fruit layer (mucilage) is left on during drying.

In every method the result is dried coffee in its shell, which is then milled to green coffee. See what parchment coffee is for that step.

Washed (wet) process

The washed process is standard in Kenya, Colombia and much of Central America. TechnoServe's wet mill guide sets out the steps:

1. Pick only ripe red cherries. TechnoServe says ripe cherries are more than 30% heavier than unripe or overripe ones, and more than 90% of a batch should be ripe.
2. Pulp the cherries within 6 to 8 hours of picking to remove the skin and most of the fruit.
3. Ferment the beans so the remaining mucilage breaks down, ideally at 20 to 25 °C. Fermentation is finished when the mucilage feels gritty, not after a fixed number of hours.
4. Wash the beans in channels that also sort them by density into grades, with the densest beans as the top grade.
5. Dry slowly, usually on raised beds in East Africa, turning the coffee every 2 to 3 hours and keeping bean temperature below 40 °C, until moisture falls from about 57% to 10 to 12%.

Some origins, including Kenya, soak the washed coffee in clean water for up to a day before drying. Washed coffees are generally known for clarity and bright acidity.

Natural (dry) process

In the natural process the whole cherry is dried, so the seed dries inside the fruit. It is common in Brazil and Ethiopia and for most robusta. Careful naturals, made from ripe cherries and dried evenly, can be fruity, sweet and full-bodied. But drying whole fruit is slower and riskier: uneven drying leads to mould and fermentation defects. TechnoServe also notes that unripe and overripe cherries are often dried this way and sold locally, so "natural" on its own does not mean high quality.

Honey and pulped natural

Between the two sits the honey process: the skin is removed but the sticky mucilage, the "honey", stays on the bean as it dries. Brazil calls this pulped natural. In Costa Rica, mills name honey coffees by colour, as Coffee Review has described:

Compared with washed coffee, honey coffees tend to have rounder acidity, more sweetness and more chocolate notes. Because the colour names are used differently from mill to mill, ask the seller how much mucilage was left on.

Other methods you will see

• Wet-hulled: common in Indonesia. The parchment is removed while the beans are still moist, then the beans finish drying as green coffee, which gives the heavy, earthy cup many Sumatran coffees are known for.
• Experimental and anaerobic fermentations: lots fermented in sealed tanks, with added yeasts or for long periods. They can score very high, but ask exactly what was done, as results vary widely.

Which process is best?

None is best in itself. Each can produce excellent or poor coffee depending on cherry ripeness, hygiene and, above all, drying. A well-made natural can outscore a careless washed lot. Choose the process that fits the flavour your customers want, then judge each lot by cupping and grading.

What to ask the seller

• Which process, and for honey coffees how much mucilage was left on.
• How long fermentation lasted and how it was controlled.
• How the coffee was dried (raised beds, patios or mechanical dryers) and for how long.
• The moisture content at milling; TechnoServe recommends 10 to 12% for parchment.
• When the coffee was milled, and a sample from the actual lot.

Lot listings on Coffee Parchment show the process for each coffee, so you can compare like with like.