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Coffee Bean GuideQuality Life Coffee中

Coffee processing

Coffee beans are the seeds of a fruit. How the skin and pulp are removed, how long it ferments and how it dries all change the taste. In general, less fruit contact means a cleaner, brighter cup; more fermentation brings sweetness, fruit and winey notes.

Classic

WashedThe skin and fruit are removed, the parchment ferments in tanks to break down the mucilage, then it is washed and dried.

Acidity: +2
Sweetness: ±0
Body: -1
Fermentation: -2

NaturalWhole cherries are dried with the fruit intact for about 2–4 weeks, so sugars and fermentation from the fruit carry into the bean.

Acidity: ±0
Sweetness: +2
Body: +2
Fermentation: +1

HoneyThe skin is removed but some sticky mucilage is left on during drying.

Acidity: +1
Sweetness: +2
Body: +1
Fermentation: ±0

Pulped naturalCommon in Brazil: cherries are pulped and dried with the mucilage on, much like honey processing.

Acidity: ±0
Sweetness: +2
Body: +1
Fermentation: ±0

Wet-hulledTypical in Indonesia, especially Sumatra: the parchment is hulled while the beans are still wet, then dried.

Acidity: -2
Sweetness: ±0
Body: +2
Fermentation: ±0

Refined

Kenyan double washedThe Kenyan way: after fermentation and washing, the parchment is soaked or fermented a second time, giving very clear acidity with blackcurrant and savoury notes.

Acidity: +2
Sweetness: +1
Body: ±0
Fermentation: -1

Experimental

AnaerobicCherries or parchment ferment in sealed tanks without oxygen before being finished as washed or natural.

Acidity: +1
Sweetness: +1
Body: +1
Fermentation: +2

Double anaerobicWhole cherries ferment anaerobically, then the pulped beans ferment anaerobically again.

Acidity: +1
Sweetness: +2
Body: +1
Fermentation: +2

Carbonic macerationBorrowed from winemaking: tanks are flushed with CO₂ so the cherries ferment from the inside.

Acidity: +1
Sweetness: +2
Body: +1
Fermentation: +2

Yeast inoculatedSelected yeast strains are added to steer fermentation, for more consistent results or particular fruit and floral notes.

Acidity: +1
Sweetness: +1
Body: ±0
Fermentation: +1

LacticConditions are set so lactic acid bacteria lead the fermentation.

Acidity: -1
Sweetness: +1
Body: +2
Fermentation: +2

Thermal shockAfter fermentation the beans are washed alternately in hot and cold water so they absorb more aroma.

Acidity: +1
Sweetness: +2
Body: ±0
Fermentation: +2

KojiUses koji mould, as in sake and soy sauce.

Acidity: ±0
Sweetness: +2
Body: +1
Fermentation: +2

Barrel agedGreen coffee or fermenting coffee rests in used whisky, rum or wine barrels and takes on spirit and oak aromas.

Acidity: ±0
Sweetness: +1
Body: +1
Fermentation: +2

Co-fermented (infused) InfusedOther fruit, juice, spices or nutrients are added during fermentation.

Acidity: +1
Sweetness: +2
Body: +1
Fermentation: +2

Decaf

Swiss Water decafRemoves about 99.

Acidity: -1
Sweetness: ±0
Body: ±0
Fermentation: ±0

Sugarcane (EA) decafCaffeine is removed with ethyl acetate made from fermented sugarcane.

Acidity: ±0
Sweetness: +1
Body: ±0
Fermentation: ±0

CO₂ decafPressurised CO₂ selectively removes caffeine while keeping more of the original flavour.

Acidity: ±0
Sweetness: ±0
Body: ±0
Fermentation: ±0

+/− show general tendencies compared with typical coffees; actual taste also depends on origin, variety and roast.