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    • Practical sheets on processing

    The processes, sheet by sheet

    What is done to the coffee between the picked cherry and the green bean, process by process. One sheet per process: the principle, the sequence with its parameters, what it gives in the cup, what goes wrong. And everywhere the same rule, separating what has been measured from what is merely claimed.

    THE PROCESS SHEETS

    32 processes, from fruit to green coffee

    Each sheet carries the scene of its process, its details and its sources. To see two processes side by side, step by step, open the plate's comparator.

    The dry process

    The dry process

    The washed process

    The classic washed processMechanical demucilagingThe Kenyan washed process and soaking

    The intermediate processes

    The honeys, from white to blackPulped naturalDried pulped honeySemi-washedWet hulled

    Directed fermentations

    Fermentation in a closed tank, called anaerobicThe natural process in a closed tankCarbonic macerationLactic fermentationSelected yeastsKoji and fungal fermentationsMicro-oxygenationThermal shockCo-fermentation and infusionDouble fermentationExtended fermentation

    Drying

    Drying, from floor to ceilingThe patioThe raised bed and drying areasShade and greenhouse dryingMechanical drying

    After drying

    Hulling and resting in parchmentWet polishingSorting, from flotation to the optical sorterGreen coffee defects and their classificationMonsooned coffeeDeliberate agingProcessing wastewater and pulp
    About forty pickers scattered across a coffee plantation on a hillside, under the tall shade trees left standing. The women, in light blouses and long skirts, carry their baskets on their heads or rest them against the hip; wooden ladders lean against the tallest coffee trees. The dispersal of the figures shows how much the harvest is work for a large labor force spread across the plot.
    Picking at Las Nubes, Guatemala, 1875Eadweard Muybridge, photographic campaign in Guatemala, 1875, albumen print from glass negative, Metropolitan Museum of Art, New York, inventory no. 2005.100.781, 1875, Public domain (CC0, Open Access of the Metropolitan Museum)

    The dry process

    The whole cherry dried on its bean, with nothing removed from it. It is the oldest of the routes and by far the most difficult: nothing protects the bean during the three weeks it dries in its own sugar.

    The washed process

    The pulp is removed before drying. The mucilage, that sticky layer stuck to the parchment, is broken down in a tank and then washed off. This is the process that gives the cleanest cups, and the one that uses the most water.

    The intermediate processes

    In between lies a whole gradient: the coffee is pulped but part of the mucilage is kept, more or less, and dried with it. The honeys and pulped natural are degrees of the same idea, not distinct processes.

    Directed fermentations

    For about ten years, fermentation is no longer endured, it is conducted: closed tank, inerting, inoculation, dosed oxygen, thermal shock. It is the most active ground of the trade, and the one where the most is claimed without being measured.

    Drying

    The processing route decides what is taken from the fruit; drying decides how the water is removed from what remains. The two dimensions are independent, and that is the whole point of separating them: a washed coffee is dried on a raised bed exactly as a natural is, and the choice of support changes the duration, the evenness and the risk of mold far more than the choice of route.

    After drying

    What happens to the bean once it is dry and still changes the cup: resting in parchment, hulling, monsooning, aging, and all the sorting that decides what goes and what stays.

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