Washed, natural, honey: what a coffee's process label means

A coffee bean is the seed of a fruit, and the process label tells you how the fruit came off that seed. A 2022 review in the Journal of Food Science and Technology, by Velásquez and Banchón, sorts the options into three methods. It calls them dry, wet and semi-dry. All three remove the fruit and leave a stable seed at 10 to 12% moisture. Roasters call the same methods natural, washed and honey.

Three layers matter if you want to follow along. The skin is on the outside, and the pulp sits under it. The mucilage clings to the seed, and it is sticky and rich in carbohydrates. The labels differ mainly in how long those layers stay on. The Specialty Coffee Association's Coffee Value Assessment lists processing information among the things that add value beyond the cup.

Washed coffee loses its fruit before drying

In washed coffee, the skin and pulp go first and the mucilage follows before the seed dries. A 2019 study in Frontiers in Microbiology, by Zhang and colleagues, describes the usual steps. A machine squeezes ripe cherries to remove the skin and pulp. The seeds then ferment underwater until the mucilage is gone, which usually takes 12 to 72 hours. After that they are washed, dried below 12% moisture and hulled. The Velásquez and Banchón review puts the water used in this method at about 40 liters per kilogram.

Washed can sound like a neutral word, but that study shows the label alone doesn't settle the flavor. The team worked with a Catimor crop in Yunnan, China, and tested several processing choices. Fermentation time had the greatest effect on the cup. A long fermentation gave a fruitier, more acidic coffee, with less of the cereal and floral notes in the aroma. Removing the mucilage by machine, which the authors call an ecological alternative, gave a comparable cup.

Real lots can vary widely under the same word. Sey lists one washed Colombian lot at 48 hours in tanks and another at eight days underwater. Both are simply labeled washed. The review says wet processed beans tend toward less body and a pleasant aroma, and that consumers accept them more readily than dry processed ones. It also warns that under or over fermenting can let spoilage bacteria and fungi grow, which brings an onion taste.

Natural coffee dries inside the whole fruit

Natural coffee skips the depulping and washing and dries with everything still on. The SCA's column on fruit-dried coffee says these are also called sundried or dry process coffees. They are traditionally linked with Ethiopia and Yemen, and the method is now used in most growing countries. Specialty producers spread ripe cherries on tables or patios. They guard them from damp and mold until they are dry enough to hull.

The flavor people remember from this style can be a strong note of blueberry jam or a lighter strawberry. Peter Giuliano's column explains where it comes from. Fruit juice soaking into the seed is the obvious guess, but he points out that coffee fruit doesn't taste like berries. Research by Mario Roberto Fernández-Alduenda, now a technical vice president at the SCA, tied the flavor to fruity compounds called esters. These form after picking, as the fruit's sugars are broken down by yeasts, other microbes and the coffee's own metabolism.

One of those compounds tastes like strawberries, and another smells like blueberries. The column also says plainly that not all fruit-dried coffees taste this way. So the word natural on a bag does not promise a berry cup.

Honey coffee keeps its sticky layer through drying

Honey coffee sits between the other two, and the name has nothing to do with bees. The review says the cherries are pulped and the seeds dry while still surrounded by mucilage, with no fermentation step to remove it. It links the name to the honey-like or sugar-like aroma left after drying. The roaster Ozone ties it to the sticky, golden texture of the layer. The review also uses the terms semi-dry and pulped natural for this method.

Color words often come with the label, and they are looser than they look. Ozone's guide gives rough figures for the mucilage kept on the bean. White honey keeps about 10 to 20%, black keeps 90 to 100%, and yellow, gold and red fall in between. More mucilage means slower drying and a darker bean. The guide also says the categories aren't strictly standardized, so one producer's red can be another's gold or black. Ozone treats pulped natural as a close cousin rather than an exact match. It says the method began in Brazil in the 1970s and usually keeps a uniform layer of mucilage.

On flavor, the review says the semi-dry method can bring more body and acidity to top quality coffees, along with caramel-fruity or herbal notes. It also reports more sucrose than in dry or wet processing. That, it says, is why pulped naturals are prized in espresso blends.

How to use the label

Treat a process word as a rough guide, and ask about the details if you care. If you liked a washed coffee and want to know why, ask about the fermentation time. With a natural, ask how it was dried, and check the roaster's own notes for the fruit you were promised. With a honey coffee, ask who assigned the color, because the grades aren't standard.

Keep the label apart from questions of quality as well, since any of these methods can go well or badly. The review's table lists high quality results for wet and semi-dry coffees, and sweet, complex results for naturals. Good roasters often print the farm's steps in full. Sey's washed lot is one example, listing floating, depulping, 48 hours of fermentation and drying on raised beds to between 10 and 11% moisture.