Natural Process Coffee

What is the natural coffee process?

A coffee bean is the seed inside a fruit known as a coffee cherry. Natural processing keeps that fruit intact while it dries; hulling, the mechanical removal of the dried outer layers, comes afterwards. The defining feature is therefore what surrounds the seed during drying, not whether the coffee touches water at any point.

Producers may clean and sort cherries using water before spreading them out. That does not turn the coffee into a washed coffee: the skin and flesh still remain during drying. In the washed process, those fleshy layers are removed before the main drying stage.

Natural processing also differs from the honey process, where the skin is removed but some sticky mucilage, the sugary coating around the parchment-covered seed, remains. For the wider framework, start with coffee processing methods.

From ripe cherry to green coffee

The basic sequence is straightforward, but each stage needs attention:

1. Harvest and sort. Remove unsuitable fruit and foreign material, including leaves and twigs.
2. Begin drying promptly. Spread the cherries rather than leaving fresh fruit waiting in sacks or unmanaged heaps.
3. Manage the drying layer. Turn the cherries, maintain airflow and protect them against rewetting.
4. Check the endpoint. Measure representative samples rather than judging the whole lot by its appearance.
5. Hull and grade. Remove the dry fruit coverings, then clean and sort the unroasted green beans.

This is a production method, not simply fruit left outdoors until it looks dry. Good naturals depend on deliberate control throughout the drying period.

Sundried Natural

A sundried natural is whole-cherry coffee dried using solar heat and circulating air. On a patio, cherries lie on a prepared surface, commonly concrete or brick, and workers move them with rakes or by hand. Turning exposes different surfaces and helps prevent persistently damp pockets.

The patio must be clean and suitable for the local climate. Bare earth introduces contamination concerns, while an impermeable surface can retain moisture beneath the coffee if poorly managed. Rain protection is not enough on its own: producers must also manage ventilation and spread the coffee back out when conditions permit.

Patio drying is not automatically inferior to raised-bed drying. FAO guidance reports that differences between drying surfaces can be small and inconsistent, while weather and the way equipment is used have substantial effects. A well-managed patio should not be dismissed merely because another coffee’s description mentions raised beds.

Some producers combine sun drying with mechanical drying. Research on Brazilian natural coffee has examined precisely this combination, including controlled resting periods between drying stages. The important distinction remains that the coffee is processed as whole fruit; “natural” need not mean exclusively sun-dried from start to finish.

Raised Bed Natural

Raised-bed naturals follow the same whole-cherry process, but the drying surface is elevated and permeable, usually mesh or matting supported by a frame. These structures are often called African beds. Their practical advantage is that air can circulate beneath the coffee as well as above it.

Elevation also keeps the drying fruit away from direct soil contact. However, a raised bed still needs appropriate loading, regular turning and protection from rain. Putting cherries on mesh does not remove the risks associated with wet weather or neglected fruit.

The useful comparison is operational rather than a ranking of prestige:

Both systems require active management; neither provides a quality guarantee by itself.

Turning and drying time

Two to six weeks is a useful broad description, not a production recipe. Kenya’s Agriculture and Food Authority gives this range for naturals, with the duration depending on country and climate. The International Trade Centre gives the same broad interval.

Sunshine, humidity, air movement, layer thickness and rainfall all affect progress. Consequently, a drying duration printed on a coffee bag tells only part of the story: it does not establish whether the coffee dried evenly or reached an appropriate final condition.

How often are cherries turned?

There is no single schedule suitable for every drying site. FAO’s mould-prevention guidance suggests turning four times daily where possible, while Codex calls for constant turning during daytime. These are general management recommendations, not interchangeable specifications for every climate and lot.

The shared principle is to avoid leaving a damp, static layer. Producers need to adapt their routine to weather and drying behaviour rather than treating a turning count as proof that the work is complete.

When is drying finished?

The endpoint should be measured. FAO’s Lao coffee manual describes natural processing to approximately 12% bean moisture, while Codex requires coffee intended for transport to be uniformly dried below 12.5% moisture. These figures concern moisture content, not the percentage of the cherry that has disappeared.

Representative sampling matters because one reading cannot establish uniformity across an entire lot. Codex recommends sampling different points and using instrumental measurements as drying approaches completion. The practical question is not “Has it had enough days?” but “Is it sufficiently and evenly dry?”

Fermentation, flavour and the risks of getting it wrong

Dry processing does not mean fermentation is absent. Microorganisms remain active while sufficient moisture is available in the fruit. A peer-reviewed processing experiment by De Bruyn and colleagues found different microbial communities and chemical profiles under wet and dry processing, including abundant acetic acid bacteria and yeasts in the dry treatments.

That study provides direct experimental evidence that processing conditions affect coffee chemistry. It does not establish a universal formula linking a particular microorganism, drying duration or chemical measurement to a named flavour in every finished cup. Its findings came from a specific case study, not every natural-producing region.

What does natural coffee taste like?

Naturals are commonly associated with fruity flavours, pronounced perceived sweetness and a heavier body. Body means the drink’s sense of weight or thickness in the mouth. These are useful expectations when choosing coffee, but not promises attached to every bag labelled natural.

It also helps to separate fruit character from fermentation defects. World Coffee Research’s sensory lexicon distinguishes fruit attributes from fermented, acetic, musty and mouldy characteristics. “Fruity” should not become an all-purpose defence for an unpleasantly tainted cup.

Over-fermentation and mould are different problems

Uncontrolled fermentation can damage flavour; mould growth is a separate spoilage concern. Delayed processing, badly managed drying and rewetting can compromise the coffee before it reaches the roaster. Later processing cannot reliably restore quality already lost through poor handling.

Certain moulds can also produce ochratoxin A, a food-safety contaminant addressed by Codex’s coffee code of practice. This is why drying control, sorting and dry storage are more than cosmetic quality measures. It is not a reason to assume that natural coffee as a category is unsafe.

Regions known for naturals

Brazil, Ethiopia and Yemen are established examples of countries where natural processing is prevalent. The International Coffee Organization associates the method particularly with locations where water is scarce, while the International Trade Centre highlights low humidity and low rainfall as favourable conditions.

Naturals are not confined to those countries, nor are they exclusive to arabica. FAO describes dry processing across several producing origins and its extensive use for robusta. Country, species and processing method are separate pieces of information, so check each rather than allowing one to stand in for the others.

For UK readers choosing a bag, my recommendation is to favour a clear description over elaborate terminology. Use this checklist:

• Is the coffee identified as whole-cherry natural, rather than pulped natural?
• Does the description distinguish patio drying, raised-bed drying or a combined system?
• Are the tasting notes appealing to you, rather than merely impressive-sounding?
• Is there useful information about the producer and handling, beyond a long drying duration?

These are reading and buying criteria, not a certification scheme. The best use of “natural process” is as a clue to how the coffee was made, followed by a judgement of the particular coffee rather than the label alone.