A coffee cherry is a fruit with two seeds inside. Processing is how the farm gets the seeds out and dry, and the method chosen changes the finished coffee dramatically. Two lots from the same trees, picked the same week and processed differently, can taste like different species.

Washed

The fruit is removed mechanically within hours of picking, the remaining sticky mucilage is fermented off in water tanks, then the beans are washed clean and dried.

Because the seed spends almost no time in contact with sugary fruit, very little fruit character transfers. What is left is the coffee itself: clean, structured, acid-forward, with the origin and varietal doing the talking. Washed coffees are what people mean by transparency, and they are the reference point for judging a terroir.

For brewing, washed lots are predictable and forgiving of small errors. They are the sensible default when dialling in a new grinder.

Natural (dry process)

The whole cherry is dried intact, fruit and all, often on raised beds for weeks. The seed sits inside fermenting fruit the entire time and absorbs a great deal of it.

The result is heavy, fruity, often boozy: strawberry, blueberry, rum, jam. Acidity reads lower and body reads higher. Done well it is spectacular. Done badly it tastes of compost and nail polish, because uncontrolled fermentation is a short trip to defects.

Naturals are more fragile in the cup. Their sugars are more soluble and they tip into over-extraction faster, so if a natural tastes muddled or boozy-bitter, try grinding a step coarser before anything else.

Honey / pulped natural

A middle path: the skin is removed but some or all of the mucilage is left on during drying. The names refer to how much was left and how much light the drying beds got.

Anaerobic and carbonic maceration

Cherries are sealed in tanks without oxygen, sometimes with CO₂ pumped in, and fermented under controlled conditions before drying. Removing oxygen changes which microbes are active, and the resulting flavour compounds are unlike anything the other methods produce.

Expect intense and polarising: cinnamon, tropical fruit, fermented pineapple, sometimes a savoury or funky note. Some people love these; others find the process buries the coffee. They are also expensive, because tank time and control cost money.

Wet-hulled (giling basah)

Mostly Indonesian. The parchment is removed while the bean is still wet, which is unusual and produces a distinctive result: very low acidity, very heavy body, earthy, woody, sometimes herbal. It is the reason a Sumatran tastes the way it does. Green beans from this process look bluish and strange.

How it changes your brewing

• Washed: your baseline. Dial normally.
• Natural and anaerobic: more soluble and easier to over-extract. Start a step coarser, and be suspicious of bitterness before you blame the machine.
• Honey: behaves close to washed, slightly sweeter and more forgiving.
• Wet-hulled: low acidity means the usual sour-versus-bitter diagnosis is harder. Lean on body and finish instead.