Once coffee cherries have been picked, they must be processed before being transported and sold. Processing should take place as soon as possible to prevent spoilage, and is typically done in one of two ways: washed or natural.
Processing has a significant impact on the final cup profile, affecting everything from acidity and sweetness to body and clarity. The processing method used by producers usually depends on a number of factors, including resources, climate, and cost.
While some consumers appreciate the bright, acidic flavours typical of washed coffees, others prefer the fruity sweetness often found in naturals. In order to make informed decisions about the coffee they buy, it’s important for specialty coffee roasters to understand the differences between the two.
To find out more about the differences between natural and washed processing, I spoke with Roosa Jalonen, Head of Production at The Gentlemen Baristas.
Why Is Coffee Processed And How Does It Affect Flavour?
Processing is an important part of a coffee’s journey from seed to cup. Without it, coffee would not be the product we recognise today.
A coffee cherry is made up of various layers, including skin, fruit, mucilage, and parchment. Once the cherries have been harvested, they need to be processed to remove these layers, so as to be left with only the coffee bean, or seed.
This can be done in a number of ways, with each method imparting a different cup profile on the coffee.
One of the most widely used processing methods is “wet processing”, also known as “washed processing”. This method involves removing the skin of the cherries (known as depulping) before submerging them in a trough of water to break down and remove the mucilage.
This can sometimes take up to 24 hours, allowing time for tiny microorganisms in the beans to create enzymes that break down the sticky outer layer. During this phase, “bad” beans float to the top and are removed, while the rest are regularly stirred to ensure all the mucilage has dissolved.
After fermentation, the beans are washed and dried, either under the sun or using dedicated drying machines (or sometimes a combination of the two). The result tends to be a coffee with high clarity, light body, and prominent acidity.
In recent years, washed processing has been incredibly popular in the specialty coffee market. It is generally viewed as an effective way of sorting out unripe cherries and other defects, and achieving a “clean” taste in the cup.
In contrast, natural processing is a method that has been used for centuries. Also known as “dry” processing, it involves spreading the harvested cherries out on a large surface to dry for several weeks with the fruit and skin intact.
The cherries are usually placed on drying beds slightly raised from the ground, such as on corrugated roofs, to ensure air circulation around the cherries. To avoid the build-up of mould and over-fermentation, they are regularly raked and turned. When the cherries reach a moisture level below 11%, the brittle outer layer is removed, and the bean within is kept for milling and sale.
Changes to weather conditions can cause inconsistency and it has been found that incorrect drying can compromise the cell walls of the beans, leading to a degradation of flavour.
Natural processing is often used in countries where water is in short supply, such as Ethiopia and areas of Brazil. Naturals often have exciting and “funky” flavour profiles that showcase the innate flavours of the bean to a stronger degree. Indeed, between 2015 and 2017, three consecutive winners at the World Brewers Cup opted for natural processed coffee.
Roosa Jalonen is Head of Production at The Gentlemen Baristas in London. She’s a certified arabica Q grader and, in 2018, was crowned Finland Cup Tasting Champion. She tells me that natural-processed coffees offer interesting and intense flavour profiles that can often set them apart from washed coffees.
“Traditionally, natural processed coffees have flavours such as ripe tropical fruits and strawberries,” she says. “I often describe them as having a little bit of ‘funk’ – in a good way.
“Because their flavours often come across as more immediate and amplified than washed, they’re often used in coffee competitions in an attempt to ‘wow’ the judges.”
Should Natural And Washed Coffees Be Roasted Differently?
As the two processing methods produce different flavour profiles, it is important to treat the green coffee differently during roasting.
Washed coffees tend to be denser than natural coffees, which means roasters should add slightly more heat during roasting to penetrate the structure of the beans.
“With washed coffees, you’re able to be much more aggressive with heat application,” explains Matt Hansell in an article for Collaborative Coffee Source. “Shorter roast times with lower-end temperatures have always been my preferred method. This is effective in highlighting the higher acidity found in these coffees.”
Natural coffees, on the other hand, are more susceptible to scorching if too much heat is added at the wrong time.
“A roast that is too fast, or lighter on the development spectrum may present itself as being harsh and imbalanced.
“Roasting a natural processed coffee requires a longer, slower drying phase and a longer development time,” Matt says. “The flavour profile of these coffees is enhanced much more with longer caramelization times.”
Furthermore, because washed coffees tend to produce greater consistency across beans, some suggest that they create a more “even” roast compared to natural coffees.
Should You Include Processing Information On Packaging?
Today, specialty coffee consumers are eager to find out as many details about their coffee as possible. In addition to roast date, flavour notes, and provenance, many also want to know about the processing method.
As well as finding out more about coffee in general, some consumers may want to know how the coffee has been processed because they have a preference for one over the other. The influence that different processing methods have on acidity, body, and flavour notes means that many people stick to coffee that’s been processed in a particular way.
“I have friends who really don’t like natural processed coffees and prefer drinking washed coffees,” Roosa says. “This information should be included on the packaging so that they can quickly identify their preferred type of beans.
“Even if it doesn’t matter to people, details like this ultimately contribute to the story of the coffee, helping to communicate the hard work of the farmer.”
Whether offering natural or washed coffee, for specialty roasters it’s important not only to understand the difference, but also to include this information on their packaging.
At MTPak Coffee, we offer a range of sustainable coffee packaging printed bags which can tell a customer which process the beans inside have gone through, or even add a QR code which can give extra educational information to customers who want to learn more about processing.
For more information on specialty coffee packaging, contact our team here.
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