Depulping equipment and settings

This topic covers the equipment and settings used in depulping coffee cherries, how the process works, and why calibration is essential for quality and efficiency in washed coffee processing.

Coffee Basics Nerds
May 25, 2025
2 min read

Article 2 of 12 in Wet Processing (Washed) Details/

What is Depulping?

Depulping is the removal of the cherry’s outer skin and most of the pulp before fermentation.
It is the second major step in washed coffee processing after sorting.
The goal is to expose beans with mucilage intact while minimizing damage.

Types of Depulping Equipment

1. Traditional Drum/Disc Pulpers

Use a rotating drum or disc with roughened surface.
Cherries pressed against a stationary plate; skin removed.
Widely used on smallholder farms.

2. Eco-Pulpers

Newer machines with water-saving designs.
Mechanically strip skin and pulp with minimal or no water.
Reduce environmental footprint.

3. Large-Scale Mechanical Pulpers

High-capacity units for estate or cooperative mills.
Handle large cherry volumes efficiently.

Key Equipment Settings

Drum/Disc Pressure: Too tight → bean damage; too loose → incomplete pulping.
Feed rate: Must be adjusted to avoid overloading.
Water flow (if used): Regulates movement and cleanliness of cherries.
Calibration: Regular checks prevent high defect rates.

Best Practices for Depulping

Ensure cherries are processed within 6–12 hours of harvest.
Regularly clean equipment to avoid contamination and off-flavors.
Separate lots to maintain traceability.
Re-run partially pulped cherries if necessary.

Risks of Poor Depulping

Over-pulping: Cuts into beans, leading to defects and lower grading.
Under-pulping: Leaves too much skin/pulp, complicating fermentation.
Inefficient calibration: Inconsistent results, lower quality.

Lasting Importance

Depulping equipment and settings directly affect processing efficiency and bean integrity. Proper calibration ensures cherries are depulped cleanly, supporting consistent fermentation and protecting specialty-grade quality.

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