Coffee Processing Methods — Natural, Washed or Honey?

Washed coffee, natural coffee, decaf coffee; it can be a bit daunting if you’re new to the terminology, but it’s simpler than it seems.

One of the most subtle pieces of information on a tasting card will be the coffee processing method used by the farmers who grew it. It’s usually a one or two worder that has big implications on what to expect from your first sip.

Coffee processing methods revolve around the layers of a coffee cherry. There are a few layers to know about:

  • Skin – the outer layer of the coffee cherry.

  • Pulp - the fruit of the cherry.

  • Mucilage - a sweet, sticky substance that surrounds the seeds on the inside- sometimes referred to as honey.

  • Chaff / Silverskin- a protective layer that falls off during the roasting process.

  • Seed / Green bean - each coffee cherry will generally have two seeds tucked inside.

Coffee processing methods refer to how we get from coffee cherry down to the green bean, ready for roasting. Different methods leave varying amounts of pulp and mucilage on the beans before they are dried which changes how they taste once they’ve been roasted. Processing coffee is a delicate procedure; green coffee can become altered during these processes which results in differing flavours in the cup. Roasters carefully cup and taste coffee before purchasing and roasting to ensure they're able to achieve the desired flavour profile.

Washed Processed Coffee

Washed coffee is one of the most popular processing methods among specialty coffee roasters. This involves de-pulping the coffee after picking, then fermenting the coffee in water tanks to soften and remove the sticky mucilage. The beans are then washed clean with more water, before being dried and shipped to roasters.

If you wash away the layers of pulp and mucilage, you’ll get very clean, crisp and acidic flavours from your coffee, with medium amounts of body and low sweetness.

Some regions will take this process one step further by fully washing their coffee. Fully washed coffee is similar to washed coffee, but instead of leaving the coffee in tanks to ferment after depulping, the mucilage is essentially pressure washed away and the coffee is immediately moved to drying patios. Fully washed coffee relies on the cherries taking in enough flavour from the climate, altitudes, and soils to produce quality in the cup- no pulp or mucilage will be adding sweetness or variety. Because of this, fully washed coffee is generally thought to be the most accurate representation of an origin.

Natural Processed Coffee

Natural processed coffee is the simplest and oldest way to get delicious flavour from an origin. Coffee cherries are picked, laid out in the sun on concrete slabs or raised beds to dry, then the dried skin and pulp is dry milled (pulled off) to get to the green beans inside. This is a slow process and can take as long as 3-6 weeks.

Flavour from natural processed coffee is affected heavily by the drying pulp; bright, juicy and fruity flavours carry through with heavy body and sweetness. Over time, natural processing has become considered a lower-quality method by some. It can be a challenge to source consistent natural processed coffee; as fruit ripens, ferments and matures at different rates, flavour can be unpredictable. However, there are equally as many people who believe natural processing has the potential to create more flavourful coffees.

Honey Processed / Pulped Natural

Two processes that are almost identical in practice; they're known as different things in different regions. Honey processed coffee sits right in between natural processed and washed coffee. With this method, the outer layer pulp is removed but leaves the sticky mucilage intact before drying in the sun. The amount of pulp left on the beans and some environmental factors can be controlled to achieve the desired flavours from the crop.

With the mucilage left intact to add depth of flavour, honey processed coffee often tastes like someone has put honey and brown sugar in your cup of coffee. These coffees often have medium levels of body and sweetness, a nice balance between the heaviness of natural processed coffee and crispiness of washed coffee.

Swiss Water Decaf

Historically, decaffeinating coffee involved chemicals ripping out all caffeine and taking a lot of the decent flavour with it. Swiss Water Decaf is special - this process involves soaking coffee in water tanks and gently heating the coffee to release the flavour and caffeine.

This caffeinated flavour water is passed through multiple carbon filters over ten hours to remove the caffeine in the water but allows the flavour to travel through. Once recombined with the green beans, the flavour you get from Swiss Water Decaf is remarkable.

Mountain Water Decaf

This Decaf processing method is essentially similar to the Swiss Water with the key difference that it is currently only performed at the ultra-modern Descamex plant in Mexico, using clear, pure water from the glacier-topped mountain of Pico de Orizaba.

During the Mountain Water Process, the batch of coffee is steamed to increase porosity before being soaked in hot water as part of the decaffeination process to extract the caffeine. This also brings forth the elements we want in the final coffee product, such as fruity acids, sugars, and fats and oils. This solution, containing both caffeine and tasty molecules, is referred to as ‘Green Coffee Extract’.

The Extract is next passed through a charcoal filter. The filter is designed to collect just the larger caffeine molecules, allowing the water and the tasty stuff to pass through. — now 99.9% caffeine-free.

This decaf extract now becomes the water base in which future batches of beans are soaked. Already at the maximum saturation of the good stuff, the extract will now dissolve just the caffeine from this second batch of beans. The cycle can then continue until an entire lot of coffee has been decaffeinated.

Why different methods are chosen

Different regions around the world have different processing methods for their coffee depending on what infrastructure they’ve invested in, what environmental variables they’re relying on and the traditions the farms have formed in processing their coffee.

When a farm is in a region where water is readily available in large amounts, they may opt to wash their coffee as it produces a quality cup consistently. If a farm doesn’t have access to the copious amounts of required water to wash their coffee, they may consume less and chose the honey process. If machinery infrastructure to wash their coffee is lacking, they can choose to simply natural process their coffee, which still produces phenomenal flavour with the right attention and care.

It really is up to the farms themselves, choosing what they have available to them, and how to showcase their coffee best.

Which is the best coffee processing method?

We explore a variety of coffee processing methods when sourcing our coffee at Allpress. As with everything we do, it’s a flavour first approach. There’s a natural processed Ethiopian in our blend The Good Brew, and a washed Brazilian in both the Allpress Espresso Blend and A.R.T. Espresso Roast.

Like most stages of the coffee journey, there is no clear winner when it comes to the best processing method – it all comes down to the unique tastes of the drinker. We don’t have any preferred coffee processing method; they all have their own unique strengths which you can explore with the single origins in our rotating Coffee Galaxy!