What Is Coffee Processing? A Complete Beginner's Guide

What Is Coffee Processing?

Coffee processing describes how coffee cherries are transformed into green beans that are ready to roast.

You will likely have heard a great number of terms used in processing language, and this can sometimes be overwhelming.

Here is the simplest explanation that I can come up with to lift the terminological veil:

There are three primary ways to process coffee:

1. Naturally Processed Coffee
2. Honey Process Coffee (sometimes called Pulped Natural)
3. Washed Process Coffee

Before you get mad at me and say that you have heard of anoxic, thermal shock, etc... Yes - these are processing methods too, but they are always applied within one of the three core processing types above: Natural, Honey or Washed.

I like to think of these as three nouns - a natural, honey, or washed process each describes a very specific framework. Everything else acts as an adjective layered on top of that foundation.

Note: In some producing countries, additional categories like wet-hulled processing exist, but these are regional variations rather than globally standard classifications.

Looking for our coffee collections based on processing method?

Check out our Natural Coffee Collection

Check out our Washed Coffee Collection

Differences Between Natural, Honey and Washed Coffee Processing

Natural Coffee Processing

In natural coffee processing, the whole coffee cherries are dried. Once dry, the coffee beans are hulled, and then packaged ready for shipment. Natural coffees are typically more fermentation-forward in their flavour expression, often exhibiting fruity, wine-like flavours.

(Photo of Naturally Processed Coffee Cherries by Basha Bekele)

Honey Coffee Processing

In honey coffee processing, the coffee cherries are pulped, leaving some or all of the mucilage on the beans, and then dried. Once dry, the remaining layers are removed during hulling, and the beans are packaged ready for shipment. Honey coffees are typically high in sweetness and lower in acidity, with lots of date and "honey"-like flavours.

Washed Coffee Processing

In washed coffee processing, the coffee cherries are pulped, fermented to break down the mucilage, and then washed clean. They are then dried, hulled, and packaged ready for shipment. Washed coffees typically exhibit clean flavours, very little fermentation-forward character, and a bright, effervescent acidity.

(Photo of Washed process coffee parchment)

Coffee Processing Comparison Table

Process	Key Trait	Flavour Profile	Risk Level
Natural	Whole cherry dried	Fruity, wine-like	High
Honey	Mucilage dried	Sweet, rounded	Medium
Washed	Fully cleaned	Clean, bright	Low

Why Does Coffee Processing Matter?

Coffee processing is arguably the most important factor in determining a coffee’s flavour profile. While terroir, variety and roast style all play significant roles, processing acts as the first major junction in shaping flavour, with everything else refining and directing that outcome.

How Does Coffee Processing Affect Coffee Flavour?

Coffee processing plays a major role in shaping how a coffee tastes. While origin, variety and roast level all influence flavour, processing determines the initial flavour trajectory and helps us to form our expectations - are we going to get a fruit-forward coffee, or a clean, floral coffee?

In simple terms, processing controls how much contact the coffee seed has with the fruit during fermentation and drying; this has a direct impact on flavour, body and clarity.

Photo: Stewart and Maun Simao operating a manual depulper in East Timor, photo of our fresh shipment of Hatuhei by Karst Organics. Read more on this here.

Natural Processing → More Fruit & Fermentation

In natural processing, the coffee is dried inside the whole cherry. This means the seed remains in contact with the fruit for an extended period, often for several weeks during drying.

During this time, sugars, organic acids, enzymes and other compounds from the fruit interact directly with the seed, as fermentation is taking place within the cherry itself.

Because the fruit is still intact for the duration of the fermentation, this provides a lot of sugar to fuel the fermentation, and so you can end up with a much more intense fermentation when compared to other methods (like washed coffee). This extended contact typically leads to more fruit-forward, boozy flavours, heavier body and more pronounced fermentation characteristics.

In addition to flavour, natural processing tends to increase perceived body and texture. These coffees often feel fuller, rounder and more syrupy on the palate compared to washed coffees.

However, this method also introduces more variability and risk at the producer level, and some farmers avoid natural processing for this reason. They also typically require significantly more labour hours per kilo to produce (due to the time spent turning, raking and attending to the cherries), which results in a higher cost to the consumer.

At its best, natural processing produces some of the most expressive, complex and unique coffees that the world has to offer.

Honey Processing → More Sweetness & Balance

In honey processing, the coffee cherries are pulped, removing the outer skin but leaving some or all of the sticky mucilage layer on the seed. The coffee is then dried with this mucilage still attached.

During drying, the remaining sugars, organic acids, enzymes and compounds within the mucilage interact with the seed. This still results in a fairly deep fermentation, but nowhere near as intense as natural processing. Because there is less fruit material involved, the fermentation is generally easier to manage and less likely to spiral out of control.

This style of fermentation often results in a profile that sits somewhere between natural and washed coffees. With honey processed coffees, you typically get elevated sweetness, a rounded body and lower acidity. This can provide luscious, complex coffees without the heavier, more boozy fermentation characteristics that naturals can produce.

However, honey processing still requires careful control. The sticky mucilage can make drying more difficult and increase the risk of uneven drying or over-fermentation if turning is not managed effectively.

Washed Processing → More Clarity & Acidity

In washed processing, the coffee cherries are pulped to remove the outer fruit, and the remaining mucilage is broken down through fermentation before being thoroughly washed away with water. Because most of the fruit material is removed early in the process, there is significantly less interaction between the fruit material and the seed itself during the drying stage. Fermentation still occurs, but the process is a lot more controlled and much less likely to go wrong.

Washed processing typically results in a much cleaner flavour profile, where acidity, florals and origin characteristics are more clearly expressed, with minimal fermentation influence.

In terms of body, washed coffees tend to be a bit lighter, silkier and can tilt in the direction of being tea-like, depending on origin and variety.

From a production standpoint, washed processing is often considered more consistent and predictable than natural or honey methods, particularly in regions with less stable drying conditions. However, it does require significantly more water than other processing methods, which can make it borderline unviable in producing countries like Yemen, where water is scarce.

At their best, washed coffees produce some of the most elegant and complex cups of coffee. At Harmony, we personally really enjoy washed processing, as we love to explore variety and terroir - washed coffees in tandem with varieties like Sidra and Gesha are excellent at this.

As a small, additional tidbit. I always find that washed coffees are incredible for experimenting with new coffee recipes. Having high clarity coffees mean that changes between approach are much easier to identify, so it's easier to spot in real time how your changes impact the final cup.

In Short

• Natural: Maximum fruit expression, heavier body, more fermentation
• Honey: Increased sweetness, balanced profile, moderate body
• Washed: High clarity, bright acidity, clean finish

Photo of roasted washed Ethiopian coffee beans from The Coffee Legends, roasted by us.

What Role Does Fermentation Play in Coffee Processing?

Almost every coffee you will ever drink has undergone fermentation. While the word can sound intimidating, fermentation is simply a natural biological process where microorganisms break down sugars — in this case, within the coffee fruit.

During processing, fermentation plays a key role in:

• Removing mucilage (in washed coffees)
• Influencing flavour development
• Contributing to sweetness, acidity and overall complexity

The duration, environment (oxygen vs no oxygen), and temperature of fermentation can all dramatically impact the final cup profile.

This is where terms like anaerobic, carbonic maceration and thermal shock come into play — they are all adjectives used to describe different ways of controlling fermentation, and provide more detail on what has happened during processing.

Why Is Drying Important In Coffee Processing?

Drying is one of the most critical stages in coffee processing.

Poorly dried coffees can introduce serious defects, such as mould, over-fermentation and uneven flavour development. They can also result in high water activity, meaning the seed (coffee bean) remains biologically active. This can lead to rapid and unpredictable changes in how the coffee roasts and expresses its flavour.

Drying coffee is a fine art, particularly in equatorial regions where conditions are highly variable.

If coffee is dried too quickly, it can significantly reduce flavour potential. Conversely, coffees dried too slowly are at greater risk of fermentation-related and drying defects.

Over the years, coffee producers have developed various methods to improve consistency and control during drying. The main ones are:

• Parabolic Drying - Coffee is dried inside a covered environment, protecting it from rainfall while allowing controlled airflow and temperature.
• Mechanical Drying - Coffee is dried using machines that control heat and airflow, allowing for fast, consistent drying.
• Patio Drying - Coffee is spread on concrete, tiled patios or tarpaulin and sun-dried, turned regularly for even drying.
• Raised Bed Drying - Coffee is dried on elevated mesh beds, allowing airflow above and below for more even drying.

At Harmony, we have a preference for a mixture of parabolic and raised beds. This makes it easier to track drying time and maximise consistency across batches.

This isn't to suggest that one method is better than another - it's simply our preference.

What Are Coffee Cherries?

Coffee cherries are small fruits that grow on the branches of coffee plants. They are often red when fully ripe, but can also ripen yellow, pink or purple depending on the variety.

Above: Photo of ripe coffee cherries by Omwani Coffee

Within a typical coffee cherry, there are two green coffee seeds (beans). These are what we roast to produce the coffee you drink.

Above: Naturally processed coffee cherries after drying.

Does Coffee Processing Affect Caffeine Level?

To answer this, it’s best to take a brief moment to remind ourselves what caffeine is, and why it exists.

Simply put, caffeine is a natural compound produced by the coffee plant. To the plant, caffeine acts as a natural insect repellent — it is an intensely bitter compound used to deter pests. At higher altitudes, where there are fewer pests, there tends to be slightly less caffeine per coffee bean, while at lower altitudes, where pest pressure is higher, there is often slightly more caffeine.

Once the coffee cherries have been picked and separated from the plant, there is very little that processing can do to influence the caffeine level (assuming the process does not involve decaffeination).

There is one exception to consider, which is drying.

Drying does not change the absolute amount of caffeine in each bean, but it does reduce the overall weight of the bean as moisture is lost. This means that, proportionally, caffeine makes up a slightly higher percentage of the bean after drying, even though the total caffeine content remains the same.

Which Coffee Processing Method Is Best?

In short, there's no such thing as a 'best' coffee processing method. Each processing method has its advantages and disadvantages, and it also depends on who is being asked.

For example, if you own a coffee farm in a water-scarce region like Yemen, then natural processing is going to be the best. Whereas, if you own a coffee farm in a region with a less consistent dry season, washed processing is going to be better than natural processing.

As a consumer, we have the wonderful privilege of being able to enjoy each processing method and selecting which we like best, but as a rough guide I've produced a comparison table below:

Attribute	Natural Process	Honey Process	Washed Process
Clarity of Flavour	Low to Medium	Medium	High
Sweetness	High	High	Medium to High
Body	High	Medium to High	Low to Medium
Acidity	Medium	Medium	High
Fruit Expression	High	Medium	Low to Medium
Fermentation Character	High	Medium	Low
Cleanliness of Cup	Low to Medium	Medium	High
Processing Consistency	Low	Medium	High
Best For	Fruit-forward, wine-like coffees	Sweet, rounded, balanced coffees	Clean, bright, high-clarity coffees

NOTE - This table is based on my own personal experience, you may disagree with some of my opinions.

Common Coffee Processing Terms Explained

• Anaerobic / Anoxic: Fermentation without oxygen, often leading to intense, wine-like flavours. Anoxic is a more specific term that means much the same thing as anaerobic. We tend to use the term 'anaerobic' at Harmony over anoxic, as more people recognise this term, and we try not to overcomplicate this.
• Carbonic Maceration: Whole cherries fermented in a sealed, CO₂-rich environment. This processing method was popularised by Sasa Sestic during the 2015 World Barista Championship.
• Thermal Shock: Incredibly rapid temperature change (either from warm to cold, or cold to warm) during processing to influence flavour and offer exceptional control. Warm to cold is most frequent, because cold water baths act as a heat sink to rapidly slow fermentation.
• Co-fermentation: Adding other ingredients to the fermentation (i.e. fruits and spices) to influence the flavour of the coffee.
• Yeast Inoculation: Sterilising the coffee cherries with ozonated water and then adding specific yeasts like Saccharomyces pastorianus to catalyse the fermentation in place of natural atmospheric yeasts. This allows the producer to create very unique and intense fermentations to create new flavours.

Final Thoughts on Coffee Processing

Coffee processing is one of the most powerful tools in shaping how a coffee tastes, acting as the bridge between the raw fruit and the final cup. While factors like origin, variety and roast all play important roles, processing is what sets the initial direction of flavour — whether that’s fruit-forward and expressive like our Esmeralda Chiroso, or clean, bright and structured like our Diofanor Gesha.

Understanding the differences between natural, honey and washed processing gives you a much clearer lens through which to explore coffee. It allows you to make more informed buying decisions, better understand what you’re tasting, and ultimately discover the styles of coffee that you enjoy most.

There is no single “best” processing method — only different expressions of quality. The real value comes from trying a wide range of coffees and building your own preferences over time.

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