What is depulping in coffee processing?

Depulping is the mechanical removal of the outer skin and most of the fruit flesh from coffee cherries, leaving the seeds (beans) still encased in parchment with mucilage attached. It is the first stage in washed, honey, and pulped natural processing - the point at which the coffee transitions from whole fruit to the parchment stage ready for fermentation, washing, or drying.

Depulping is performed using a pulping machine - a device with rotating drums or discs that squeeze the cherry, forcing the seeds out through an aperture while the skin and pulp are expelled separately. The quality of depulping matters: a well-calibrated pulper set to the correct size for the cherry being processed removes skin cleanly without damaging the beans or leaving excessive pulp attached. A poorly calibrated pulper cuts beans, leaves skin fragments attached, or crushes cherries rather than cleanly separating them - all of which introduce defects.

For smallholder producers, depulping machinery is often shared through a cooperative or washing station, making it one of the key service inputs that cooperative membership provides. The timing of depulping after harvest is also critical - cherries should be depulped as soon as possible after picking, as fruit that sits too long begins fermenting in cherry before any controlled processing can begin.