Your Pocket-sized Guide

to Coffee Processing

Washed, natural, honey – perhaps you’ve come across these terms as you’ve explored the somewhat mystifying world of coffee.

These all refer to different ways of turning a coffee cherry from a tree into a green (unroasted) bean.

From the slopes of Ethiopia to Honduras, every farmer has their preferred (or prescribed, but more on that below) processing method that’s best for their crop, as well as what suits their climate and budget best.

The oldest way to process coffee is also the simplest: leave it out to dry.

Aptly also known as ‘dry processing’, this method originates in Ethiopia and is most suitable for regions with a drier climate. In natural processing, the coffee cherry is left intact for the entire period, which can take between a month and six weeks to complete.

Batches of cherries are sorted onto woven mats which allow air to circulate from under and over the cherries. Because the cherry is important for this process, only the best and most ripe fruit is picked. Coffee berries begin fermenting as soon as they’re laid out, so the lots need constant attention and are turned and checked regularly.

Once the fruit has completely dried out, the cherries are milled and the skin is removed, leaving the green beans ready for storage and shipping.

Natural processed flavors are majorly influenced by the drying pulp, and these coffees are known for their bright fruitiness.

Washed processing is most common in Africa, Central and South American regions where there are cool overnight temperatures and warm days.

Unlike naturally processed coffee, the washed process requires a lot of water. Because the cherries and seeds go through multiple rounds of washing and rinsing, regions with scarce water are less likely to use this method.

There’s also more equipment used for this method, so farmers with limited access to funding are less likely to use the washed process. However, it’s less labor intensive and faster than natural, so there are nuanced factors that contribute to a farmer’s choice.

Once picked, coffee seeds are removed from the fruit within 12 hours of harvesting. These seeds are left to ferment in tanks of water, with floating seeds scooped from the surface and thrown away.

Like other seeds, coffee seeds are naturally covered in sticky remnants of fruit and sugar called mucilage. To get rid of it, the seeds are left in fermentation tanks filled with water. The tanks are periodically emptied and then filled again until the water runs clean and the seeds aren’t sticky anymore.

The seeds are then dried on massive tarpaulins for up to two weeks and raked regularly to keep the seeds from sitting in one position too long and drying out unevenly or developing mold.

Dry green beans are stored in sacks with their parchment layer, or silverskin, on. These are only removed in a mill just before shipping.

Washed processed coffees are known for their crisp and acidic finishes, with less fruity and fermented notes.

Combining elements of both the natural and washed processes, honey coffees require meticulous care and yield a wide range of flavors. Popularized in Central America, Costa Rican techniques are widely seen as the standard for this method (spoiler: there’s no actual honey involved at all, apologies to any small and curious bears reading this).

Like washed coffees, honey coffee cherries are de-pulped within 12 hours of harvest. The difference comes in next: the mucilage (sticky remnants of sugar and fruit) is left on the seeds for some or all of the drying process instead of being rinsed off.

These seeds are not ever washed, just like with natural coffees. Leaving some of their pulpiness intact amplifies the fruitiness inherent in a coffee cherry.

Honey coffees are generally separated into three colors: yellow, red and black. For yellow coffees, the sticky seeds are spread over tarpaulins under full sun and raked thin to speed up and even out their drying. Red and black coffees are first stored in heaps in greenhouses before being agitated, raked, and aerated.

Because of their longer fermentation times, red and black honey coffees taste more fruity and boozy with creamier bodies. Yellow honey coffees are the mildest of the three in fruitiness, closer to a traditional washed coffee with its bright clarity.

Another term that you may come across is ‘anaerobic’ coffee, an experimental fermentation method that can augment any process. So you could get an ‘anaerobic washed coffee’, for example.

After being picked, coffee cherries undergoing anaerobic processing are stored in airtight containers. Being deprived of oxygen in fermentation draws out and brightens exciting characteristics of the coffee cherries that farmers wouldn’t be able to otherwise (think tropical and spicy flavors).

Depending on the farm and chosen equipment, the coffee is stored in sealed sacks or tanks for anywhere from 48 to 72 hours before being moved on to drying. Still a fairly new process, we’re in the early stages of using the anaerobic method to discover different personalities from coffee cherries. The future is bright (and juicy!).

The Case for Resting Coffee