Coffee cherries have thick outer skins and a layer of mucilage that slows down the evaporation of moisture, resulting in a longer drying process.
Drying Coffee Cherries:
Because of their thick skin and high moisture content, coffee cherries should be spread thinly—about 3–5 cm thick—on drying patios. During sunny days, the cherries should be turned every 3–4 hours to ensure even drying. The drying process is considered complete when the moisture content reaches 10–12%.
Mechanical Drying of Coffee Cherries:
Freshly harvested, wet coffee cherries should not be placed directly into dryers. Instead, they should first be partially sun-dried for 4–5 hours, allowing surface water to evaporate. At this stage, the cherries typically have an initial moisture content of 40–45%.
Table 8: Coffee Cherry Drying Stages
|
Stage |
Drying Time (hours) | Drying Temperature (°C) | Duration (hours) |
Notes |
|---|---|---|---|---|
| 1 | 0 – 20 | 70 – 75 | 18 – 20 | The first stage depends on the initial moisture content of the cherries. |
| 2 | 20 – 24 | 50 – 55 | 3 – 4 | — |
Technical Summary:
-
Stage 1: Dry at a higher temperature (70–75°C) for 18–20 hours to quickly remove surface moisture.
-
Stage 2: Lower the temperature to 50–55°C for 3–4 hours to allow uniform drying and stabilize remaining moisture.
-
When finished, the final moisture content should reach 10–12%, suitable for storage or hulling.