How Coffee Beans Are Dried After Washing

Once coffee cherries are washed and pulped, the beans still hide inside a sticky, protective layer called the parchment — and that parchment holds onto around 15% water. That’s too wet for safe storage. If you’ve ever wondered why freshly processed coffee needs days under the sun or in a machine, this is the step that makes or breaks the beans’ stability before export.

The goal is simple: dry the parchment-covered beans down to 11% moisture. That precise level keeps the beans stable, prevents mould, and avoids quality loss. Go too low — like 10% — and the beans lose their signature blue-green colour and start to degrade.

Why Drying Happens Inside the Parchment

Right after washing, coffee beans are encased in a thin, papery layer known as the parchment shell (or endocarp). This layer shields the green bean and locks in remaining moisture — usually around 15%. Until that moisture drops to about 11%, the beans remain vulnerable to mould, fermentation, and physical damage. That’s why the post-wash drying phase focuses entirely on reducing water content while keeping the parchment intact.

How the Drying Process Works

Drying parchment coffee is a slow, controlled process. The beans are spread out in a single layer — traditionally on concrete patios, stone slabs, wooden tables, or trays — and left to dry under the sun. This mimics traditional drying methods, where exposure and airflow do the work over many days. But environmental factors like rain or harsh sunlight can complicate things.

Larger farms or regions with unpredictable weather often use mechanical dryers instead. In these systems, beans are placed in climate-controlled chambers where conditioned air circulates evenly around them. Yet in sunnier, drier climates, producers still rely on the original method: sun drying.

Sun Drying: Time, Technique, and Caution

When drying outdoors, workers spread the parchment coffee in a thin, even layer and turn it regularly to ensure even exposure. This manual turning is crucial — without it, beans underneath may stay too wet. The process takes approximately 12 to 15 days under the sun. During this time, the layer must be flipped multiple times daily. One critical rule: never let the sun get too strong. If solar radiation spikes, the beans must be covered to avoid cracking the parchment. Once the parchment dries to 11% moisture, the beans are stable — but the outer shell stays on until just before export.

What Is Parchment Coffee?

After drying, the beans are encased in that dry, crinkly parchment layer — earning them the name “parchment coffee.” This protective shell keeps the beans safe during storage and transport. The parchment doesn’t get removed until just before roasting, during a step called milling or hulling. Most coffee worldwide is traded and stored as parchment coffee, especially when it’s being kept for months before export.

Storing Parchment Coffee Safely

Because coffee-growing countries often need to export year-round — not just immediately after harvest — parchment coffee is stored for weeks or months under strict conditions. Heat is a major threat: temperatures that are too high will degrade the beans. Humidity is even riskier. At 70% relative humidity, mould and stale flavours set in fast.

For that reason, parchment coffee isn’t usually stored at the farm unless there’s no alternative. Instead, it’s moved to climate-controlled warehouses. Highlands-grown beans are especially sensitive to humidity and should be stored at elevations close to their origin. Under proper conditions, arabica beans shouldn’t sit in storage for more than 12 hours, while robusta can last slightly longer if humidity and heat are controlled.

Frequently Asked Questions

What is the ideal moisture level for dried parchment coffee?

The target moisture content is 11%. This level ensures the beans remain stable, protect their quality, and avoid mould or degradation during storage and transport. Going below 11%, such as to 10%, risks damaging the bean’s colour and structure.

How long does sun drying take for coffee beans?

Sun drying typically takes 12 to 15 days. During this period, the beans must be spread in a thin, even layer and turned regularly to dry uniformly. Workers often cover the beans during peak sunlight to avoid overheating or cracking the parchment.

Why is the parchment layer not removed immediately after drying?

The parchment protects the green coffee bean from physical damage, moisture, and odours during storage and transport. It is usually removed just before roasting in a process called hulling or milling, which reveals the green bean underneath.

Can coffee be dried too much?

Yes. Over-drying coffee beans to below 11% moisture — such as 10% — can cause the beans to lose their natural blue-green colour, become brittle, and suffer quality loss. That’s why precise moisture control is essential during drying.

Where is parchment coffee usually stored?

Parchment coffee is stored in climate-controlled warehouses, not on the farm, to avoid exposure to heat and humidity. Arabica beans are ideally kept at elevations similar to where they were grown and should not be stored for more than 12 hours in hot or humid conditions.

Recommended FrontStreet Natural-Process Coffee Beans

Explore FrontStreet Coffee’s selection of naturally processed beans that highlight the impact of careful drying. The FrontStreet Ethiopia Humbera is a stellar example of Ethiopian highland coffee, featuring delicate floral aromas and complex fruit notes when sun-dried properly. For a bold yet fruity profile, try the FrontStreet Yirgacheffe Red Cherry, made from fully ripe cherries dried on raised beds to enhance sweetness and acidity. Another standout is the FrontStreet Sidra from Colombia, which undergoes a unique double anaerobic natural process to deliver explosive tropical fruit flavours. All are excellent examples of how drying — including sun exposure and controlled fermentation — shapes the final cup. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.