Processing, properly

What process is deciding

Under a cherry’s skin and pulp sits mucilage, a sticky, sugary layer on the parchment, the papery shell around each seed. Every process decides how long that fruit stays on, and what the microbes get up to.

Washed and natural, properly

Washed: the cherry is pulped and the mucilage ferments in tanks, usually something like twelve to thirty-six hours, until it washes off. Natural: the whole cherry dries on patios or raised beds, raked often, for up to about four weeks.

The washed route

Put a washed coffee through the mill in order.

1. Pulp the cherry
2. Ferment off the mucilage
3. Wash it clean
4. Dry the parchment

Pulp, ferment, wash, dry. A natural skips all four and dries inside the whole fruit, and puts more things at risk.

Same farm, two lots

One lot washed, one natural, same farm and day. Which tastes more of fruit?

Answer: The natural. More time in the fruit puts more fruit in the cup, and washed lots from the same farm read cleaner and brighter.

Honey, by color

Honey pulps the cherry but leaves mucilage on as it dries. Costa Rican mills name it by color: white and yellow a little, red more, black nearly all. Each draws the lines differently; the more that stays, the nearer a natural.

Two red honeys

Two mills both sell a red honey. Why might the coffees still differ?

Answer: Each mill draws the lines differently. The lines are loose, each mill a law unto itself: some go by how much mucilage stays on, others by how slowly and how shaded the coffee dried.

Indonesia’s shortcut

Rain makes weeks of drying a gamble in Sumatra and much of Indonesia, so farmers dry the parchment a couple of days, hull it while still damp, then dry it bare: wet-hulling, or giling basah. Money sooner, and a bluish bean.

India’s monsoon

Months under sail to Europe left Malabar coffee swollen and pale. Now natural beans lie in open-sided coastal sheds for 12–16 weeks of the June–September monsoon to swell, turn straw-gold and lose acidity: Monsooned Malabar.

Out of the monsoon

After 16 weeks in the monsoon wind, the coffee’s acidity has…

Answer: Dropped a long way. Weeks of damp sea air mellow the bean as the voyages under sail once did, leaving a heavy-bodied cup, often with a note of spice.

Anaerobic, and other adventures

Some lots ferment in sealed tanks or bags with the air shut out, so other microbes win: anaerobic fermentation. Carbonic maceration ferments whole cherries under CO2; a world barista champion used one in 2015.

Which process, which cup

Join each process to the cup it tends to give.

• Washed — Clean and bright
• Natural — Fruity and sweet
• Wet-hulled — Heavy, earthy, low in acid
• Anaerobic — Winey, sometimes boozy

The fruit left on the seed, and the microbes dining on it, decide most of this: washed reads clean, natural fruity, wet-hulled heavy, anaerobic winey.