Processing – a look at where coffee flavour begins

Coffee flavour starts taking shape long before roasting. One of the biggest factors influencing taste is how a freshly picked coffee cherry gets from the tree to a dry, export-ready bean — in other words, how the coffee is processed. The same variety from the same farm can taste completely different depending on which method the producer chooses. Over the years, we've even carried the same coffee both as washed and as natural. Take Danche, for example, which at the time of this post's publication is available as a natural.

Let's go through the most common methods, and why they taste so different in the cup.

Natural

Natural — also known as the dry method or sun-dried method — is the oldest and most traditional way of processing coffee. In the natural process, the whole cherry is dried with its skin and fruit flesh still intact, on concrete patios or raised drying beds. The cherry essentially "steeps" in its own fruit as it dries over several weeks, which pushes flavour and sweetness into the bean.

Taste — fruity, full-bodied, sweet

The result is typically a heavier-bodied, rich and fruity cup with noticeably less acidity than washed coffee. The risk lies in consistency: if drying isn't even and carefully managed, the coffee can taste fermented or unclean. Done well, though, natural is one of the most interesting ways to taste a coffee's fruit character.

Try a natural-processed coffee: Danche Natural

Washed

In washed — or wet-processed — coffee, the skin and fruit flesh (the mucilage layer) are removed mechanically right after picking. The beans are then fermented in water, usually for 12–48 hours, to loosen the remaining sticky parchment layer. After fermentation, the beans are washed and dried.

The washed process is the most common method in the world and is often the safest choice in humid or unstable conditions. Because no fruit flesh is left to dry on the bean, the risk of spoilage or quality loss is significantly lower than with the natural drying process.

Taste — clean, bright, acidic

The result is typically a clean, refined, acidic cup, where the character of the variety and growing region comes through clearly, without the sweetness the fruit flesh would add.

Try a washed coffee: Siko Washed

Image: Honey-processed coffee beans on the left, natural-processed coffee beans on a drying bed on the right.

Honey process

Honey process sits between washed and natural: the skin is removed mechanically, but some or all of the mucilage (that sticky fruit flesh) is left on the bean while it dries. The more mucilage that's left on, the closer the result moves toward a natural-style coffee — sweeter and more full-bodied.

The amount of mucilage left on the cherry is often described using additional labels like "yellow," "red," or "black" honey.

• Yellow Honey = only a little fruit flesh
• Red Honey = more fruit flesh
• Black Honey / Full Honey = a lot of fruit flesh

Try a honey-processed coffee: La Catarata

Fermentation is at the heart of every method

And that's not quite everything. You've probably come across various fermentation terms on your coffee journey too, so let's unpack those as well.

Fermentation happens in some form in every process described above: in washed coffee it takes place in water tanks as the mucilage is removed; in natural and honey it unfolds more slowly, alongside drying, while the fruit flesh is still on the bean.

In recent years, though, producers have started taking this stage into their own hands, developing more precise ways of controlling it. Cherries can be fermented in their own sealed tanks before the actual drying begins. These controlled fermentations have become their own category, one that can be combined with any of the base processing methods mentioned above.

Image: washed coffee beans fermenting in a barrel.

Anaerobic fermentation

The word anaerobic means oxygen-free, though with coffee it's rarely a fully oxygen-free environment. Whole or pulped cherries are sealed into airtight tanks, where fermentation takes place under controlled, near-oxygen-free conditions. The process typically takes anywhere from a few hours to a few days, depending on the intended result. With oxygen removed, microbial activity shifts: different acids, alcohols and aromatic compounds form than in open, oxygen-present fermentation. In practice, this often boosts sweetness and fruitiness, and at its most intense can bring in notes that get described as "funky," winey, or even "boozy."

Thermal shock

In this method, cherries are exposed to sudden temperature changes during or at the end of fermentation — for example, submerged first in hot water and then quickly into cold, or the reverse. The thermal shock halts or triggers microbial activity in a controlled way and breaks down the cherry's cell structure, which can bring extra sweetness and more intense, sometimes exotic aromas to the cup. This method is often used alongside anaerobic fermentation.

Co-fermented

Here, something extra is added to the fermentation tank alongside the cherries — fruit, fruit juice or peel, sometimes yeast strains or other microbial cultures. These additions change the course of fermentation and bring flavours to the cup that wouldn't develop from the cherry alone. Co-fermented coffees tend to be the boldest and most experimental in flavour profile, and they're also a hot topic of debate within the industry — for and against.

What all three have in common is tight control: temperature, time and the microbial environment directly determine whether the cup ends up clean and balanced and fruity, or leans wilder, toward overripe fruit. Done well, these methods bring layers to a coffee that traditional washed or natural processing can't reach — done poorly, the result can taste stale, boozy, or unbalanced.

Why this is worth knowing when buying coffee

The processing method often says even more about a coffee's flavour profile than the roast level.

• If you're after a bright, acidic cup and like to drink your coffee black, washed coffees are worth exploring.
• If you prefer full-bodied, sweet, fruity cups — maybe with a splash of milk — natural- and honey-processed coffees are likely more your style.

Browse our full range and filter coffees by processing method: All coffees →