What Is Washed Coffee, Unwashed Coffee, and Semi-Washed Coffee?

Written by:
Claire Iverson
Photography By:
Dennis Tang

The coffee beans you grind at home are not what comes off the tree. In fact, there’s a whole series of processes that take place before the bean gets bagged and shipped to you.

One of these is the washing process, which does exactly what it sounds like: with tons of water and specialized equipment, the beans are sorted by quality, as well as pulped and fermented.

Yet, washing coffee is just one of the ways to process beans. Producers can also dry wash or semi-wash, and each process reveals different bean flavors.

Read on to learn which process makes your perfect cup of coffee!

Why Would We Wash Coffee?

Washed coffee with water

Coffee beans are not actually “beans.” Technically, they’re a type of fruit. Or, more specifically, they’re the pit of a cherry that comes from the Coffea plant.

When the pit is removed from the cherry, it’s known as a green coffee bean. Only after it gets roasted does it take on that beautiful brown color we all know and love.

But for some coffee beans, there’s another step between picking and roasting — removing the mucilage, also known as “washing” the bean.

Why would you do this? Imagine you’re eating a peach. You gobble up the fruit and just barely miss eating the pit. You try to lap up the final drops of juice on the pit but can’t quite lick it clean because it’s covered by a sticky, sweet gloss. For coffee beans, this layer of gloss is called mucilage.

While the fruit flavor of the mucilage might sound desirable to some, it often overpowers the flavor of the actual bean. So for some producers, washing the bean is preferable, as it allows the flavor of the bean to shine through. To taste this in action, check out Backyard Beans Coffee Co., which primarily sources washed beans.

How Does The Coffee Washing Process Work?

Washed Coffee Machine

The washing process requires high-quality beans, specialized equipment, and tons of water — which is also why washing is referred to as the “wet process”

To begin the washing process, cherries go through a quality test. They get poured into a basin of water. The good ones float; if they’re young or rotten, they sink to the bottom.

Next, a machine called a depulper removes the outer skin and fruit of the cherries. So all that remains on the pit is the mucilage layer.

In the next step, a fermentation process fuses the mucilarge’s sugars and acids to the pit. Typically, fermentation lasts 24-72 hours. For a bolder fruit flavor, ferment longer. For a softer flavor, ferment briefly.

Fermentation — as well as a final washing — breaks down and removes the mucilage layer, ensuring a crisp, acidic, clean flavor.

What Is Unwashed Coffee?

Unwashed coffee drying in the sun

Unwashed coffee — also known as “dry processed” coffee — is, as the name suggests, not washed.

Typically, producers leave their beans unwashed for three reasons.

On the one hand, it’s the oldest, most natural way to process coffee. The process of laying the whole fruit on a flat surface to dry in the sun for weeks — similar to drying grapes into raisins — has been practiced by farmers and agriculturists for hundreds of years.

Additionally, the drying process is both easier and cheaper than washing. You don’t need the fancy machinery and loads of water to get flavor. All you need is a place to dry the fruit, a few workers to tend to the beans — occasionally shuffling and rifling through the pack –, and time.

For coffee consumers, dry processed beans often yield wild, explosively sweet, earthy flavors. You never really know what you’re going to get. There could have been a rotten cherry in the group that wasn’t noticed, or there might have been a cherry that wasn’t churned over the weeks so its been burnt by the sun. While these might produce bitter tasting coffee, they could also produce complex and uneven flavors that many coffee experts and enthusiasts enjoy.

To experience unwashed beans, look up Need More Roasters Coffee’s 18 Rabbit blend, or Limitless Coffee’s lightly caffeinated sparkling water.

What Is Semi-Washed Coffee?

Semi-Washed Coffee

Rather than leaning to one processing extreme, semi-washing, also known as the honey process, hybridizes the washed and dry processes.

Similar to the washing process, semi-washing removes the skin and meat from the pit.

However, it doesn’t go the extra mile and removes all the mucilage. Rather, some mucilage remains on the pit for the drying step.

Furthermore, most parts of the semi-washed process can shift to align with the producer’s desired flavor outcome.

Steps with room for variation include what time of the day the cherries are pulped, when the fruit is washed, overnight air temperatures, and of course how much mucilage remains after fruit removal.

For coffee consumers, semi-washed coffee tastes like a mix of washed and dry processed coffee. There is a syrupy sweetness with earthy undertones.

To taste semi-washed coffee for yourself, check out Homestead Coffee Roasters Sumatra blend.

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