What is pulping in coffee processing?

Pulping is the mechanical removal of the outer skin from a coffee cherry, exposing the mucilage-coated parchment below. It's the first step in washed, honey, and pulped natural processing, and happens at the wet mill immediately after cherry intake.

The pulping machine - typically a rotating drum or disc with a rough surface - passes cherries through a gap calibrated to cherry size. Friction and pressure remove the skin as each cherry passes through, leaving the bean in parchment with mucilage attached.

Calibration matters: too tight a gap and beans get cut or chipped; too loose and skin isn't fully removed. The quality of pulping - how cleanly the skin is stripped without damaging the bean - has a direct effect on fermentation efficiency and defect rates in the finished lot. After pulping, coffee moves to fermentation tanks (washed), to drying beds with mucilage intact (honey), or to mechanical demucilage machines.