Just what the hell is… Dry and Wet Processing?

September 23, 2017

When talking about coffee, processing is the first stage in how coffee beans are made. It involves taking the coffee cherries from the tree and turning then into green, unroasted beans that can be sold to distributors or direct to coffee roasters. The next stages are roasting then brewing then drinking. Yum.

When the coffee cherries ripen, some four to five years after the plant is grown, they are a long way from the sparkling brown coffee beans that are dropped off by your local mailman from your local roasters. The cherries need to be processed at the farm where they are grown or somewhere nearby before they make the long journey to where they are used.

farmer holding coffee cherries

A farmer holding the coffee cherries.

Dry-processing coffee beans, also referred to as natural processing, is the traditional, low-tech method to getting the farmed coffee cherries to a sellable green, unroasted coffee bean. This is the alternative to the much more common wet-processing, or washing/washed, which uses a lot of water and machinery to get the same result.

coffee cherries drying

Dry processing leaves the coffee cherries out in the sun for long periods.

the machinery used for wet processing

Wet processing uses machinery and lots of water to remove the cherry and mucilage from the bean.

In dry-processing the coffee cherry is dried out in the sun as soon as it has been picked. In wet-processing the coffee cherry is removed by machine and then the coffee bean is dried out in the sun. In many countries, natural processing is impossible because of the humid conditions that cause the fruit to rot before it has fully dried out.

There are a couple of other methods that you may come across. These occupy the middle ground of dry and wet processing where only some water is used and only some skin is removed. These techniques have names like semi-washed, wet-hulled or honey processing. I might get to these in another article. In the meantime, here’s a great link on the subject.

Dry Processing Wet Processing
Other Name Naturally Processed Washed
Step 1 Coffee cherry is picked from the Coffea plant Coffee cherry is picked from the Coffea plant
Step 2 Let the cherry dry out in the sun and let it darken from red to black The coffee cherries are submerged in water
Step 3 Left for 4 weeks and raked and turned periodically The bad/unripe ones float, the good/ripe ones sink
Step 4 The cherry is peeled to get the coffee bean A machine is used to remove all the cherry
Step 5 Sent to get hulled, sorted, graded and shipped Let the coffee bean dry out in the sun
Step 6 Sent to get hulled, sorted, graded and shipped

What’s the difference?

Traditionally, dry-processed coffee beans have been considered lower grade and poorer quality. This remains true for the majority of DP coffee sold around the world today. The farmers receive little money for their DP coffee beans and so little care is taken in the farming and processing. Some governments have even banned dry-processing to help farmers make more money. They’re considered a cheap commodity.

a farmer with green coffee beans

Wet-processed coffee beans make up most of the coffee sold around the world. The process requires a lot more machinery and, like Arabica is, they have been considered to be the gold standard in good coffee for a long time. But this is changing.

It’s true that a really good DP coffee is hard to do right. It takes a whole lot of skillful manual labor with well-trained workers, something of a reach for poor coffee farmers who don’t even have access to the equipment to make washed coffee. Most would prefer to take the small amount of money they get for their cheap dry-processed coffee beans.

This is beginning to change. There is a growing market for premium naturally processed coffee and for very interesting reasons. I’m going to explain why.

The biggest and most exciting development is in the taste. Dry-processing the coffee cherries in the sun allows a small amount of fermentation to take place. This gives the coffee you drink an extra pang of fruitiness and sweetness with notes of berries and tropical fruits really shining. This is in contrast to wet-processing which is thought of more as the classic coffee taste, which still retains inherent flavors but they don’t pop quite as much.

The big issue with DP coffee is how tough it is to get right. If the conditions and methods aren’t handled properly it’s easy to have a coffee overwhelmed with biting sourness. It’s simple to put your coffee cherries out in the sun. It’s much more difficult to put them out in the right way ont he right equipment where the air-flow is good and they are turned and managed properly.

the continent of africa

Where do they come from?

Most DP coffees you will see come from Africa. The first reason for this is the conditions in Africa. Dry-processing is only possible in hot but dry climates where the coffee cherries will dry out in the sun before the fruit itself starts to degrade and rot. The parts of Africa in the coffee belt are very well suited for this.

The second reason is the tastes that are magnified go well with African coffee. Coffee beans from the African continent are noted for their sweetness, light acidity and fruitiness which complements the flavors dry-processing brings out. Asian coffees, on the other hand, are noted for their musty, earthy flavors which don’t pair up quite so well.

Another part of it is the large quantities of water required for wet processing. The kind of quantities that are not readily available to the average African coffee farmer.

Advantages of good naturally processed coffee beans

It’s true that DP coffee beans are difficult to get right. But when they’re good, they’re really good. They enhance the flavor profile of the coffee bean in much the same way as single origins do compared to blends. Flavors are enhanced, particularly brighter and acidic tones. If you get excited at the prospect of notes of lemon, honey and tropical fruit lighting up your tongue, you should give these a try.

Another consideration is that DP is more ethical, environmentally speaking. Washed coffee uses lots of water and electricity where the dry-processing uses little more than manual labor. The sun is the source of energy. And anything that uses less water on a continent where some of the lakes have decreased in size by 90% can only be a good thing.

How to get good DP coffee

We are a lucky generation. One that happens to be enjoying coffee several years after the birth of the Third Wave of coffee. What this means in practical terms is there are high quality coffee roasters hiding in every city, town and village across the country. These days, the majority of independent coffee roasters really know what they’re doing so if you see ‘naturally processed’ or ‘dry processed’ on the bag then you can be pretty sure it’s been checked and it’s a good one.

The best option is to find your local indie coffee roasters and go down there and see what they’ve got. If there’s one thing coffee roasters love, it’s to drone on and on with details about the coffee they’re making. And that’s great for you.

I’ve said it before and I’ll say it again: The best thing you can do to start making great coffee at home is to be high quality freshly roasted coffee beans. There is probably a fantastic local coffee roaster plying their trade in your hometown and even if not there’s some great online coffee roasters that will deliver freshly roasted (we’re talking 1-2 days old) coffee straight to your door.

(The second best thing is to invest in a good (read: $100+) coffee hand or automatic grinder.)

a pretty looking coffee farm

A coffee plantation in a place much sunnier than where I live.

– If nothing else, it’s nice to look at your bag of freshly made beans and understand what the ‘washed’ on it means.

– As a quick reco, I’ve been absolutely loving a DP Ethiopian Guji recently. The sweetest notes of cherry are just a joy on a Monday morning.

– If you’re interested in what happens to the green coffee beans after they are shipped then check out my in-depth article on the roasting process.

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