Open any specialty coffee bag and somewhere on the label you'll find a word like "washed", "natural", "honey", or "anaerobic". For most people, these are noise. They sit between the country of origin and the tasting notes and seem like the kind of detail only a barista should care about.
They actually matter more than the country of origin in how the cup will taste. A natural-processed Ethiopia and a washed Ethiopia from the same farm are radically different coffees. If you've ever bought "Ethiopia" expecting one flavour and got the opposite, processing is usually why. This guide explains what each method is, what it does to the bean, and how to use the label to pick a coffee you'll like.
The processing problem
Coffee is the seed of a fruit. The cherry has a sweet, sticky fruit layer around it, a slimy pectin layer (called mucilage), and a parchment skin. To get from a freshly-picked cherry to a green bean ready for export, you have to remove all of those layers without spoiling the seed.
You can do this in several ways, and the method you choose determines:
- How much of the fruit's sugars and acids get absorbed into the seed during processing
- How quickly the bean dries (and thus how stable it is in storage)
- Whether wild fermentation happens, and if so, how much
Those three variables produce the categories below.
Washed (fully washed, wet)
The clean, sharp method. Cherries are de-pulped (the outer fruit removed mechanically), then the beans sit in water tanks for 12–48 hours while enzymatic fermentation breaks down the remaining mucilage. The beans are then washed clean and dried on patios or raised beds.
Because the fruit is removed early, very little fruit character transfers to the seed. What you taste in a washed coffee is the seed itself — clean, structured, with whatever acidity and origin character the variety brings on its own.
Tastes like: clarity, brightness, defined acidity. Apple, citrus, black tea, florals. A "clean" cup.
Good for: filter brewing where you want to taste the bean clearly. Espresso when you want clarity over body.
Classic examples: Washed Kenyan SL28, washed Colombian Caturra, washed Ethiopian Yirgacheffe.
Natural (dry-processed)
The oldest method. Whole cherries are spread on patios or raised beds and dried in the sun — fruit, pulp, mucilage and all — for 2–4 weeks. The fruit ferments and partially absorbs into the seed during this period.
Done well, natural processing produces sweet, fruity, sometimes wine-like cups with a heavier body. Done poorly (uneven drying, mould, over-fermentation), it produces vegetal or boozy off-flavours. The technique requires consistent weather and constant raking.
Tastes like: stone fruit (peach, apricot), berries (blueberry, strawberry), tropical fruit (mango, papaya), honey, fermented notes. Bigger body than washed.
Good for: filter when you want a sweet, fruit-forward cup. Espresso when you want sweetness and body. Often great as cold brew.
Classic examples: Natural Ethiopian Sidamo, natural Brazilian Mundo Novo, natural Yemeni heirlooms.
Honey (semi-washed, pulped natural)
Halfway between washed and natural. The outer fruit is removed mechanically (like washed), but the mucilage is left on the bean during drying (like natural). The mucilage looks like honey on the parchment — hence the name.
The amount of mucilage left on determines the sub-category: white honey (most removed), yellow, red, black honey (most retained). More mucilage = more fruit character + more risk.
Tastes like: a balance — sweetness and body from the mucilage, but the cleaner acidity of washed processing. Often: stone fruit, caramel, brown sugar.
Good for: people who find natural coffees too wild and washed too austere. A versatile middle ground.
Classic examples: Costa Rican honey-process lots, Salvadoran honeys.
Anaerobic (fermented in sealed tanks)
The newest, most experimental category. Cherries (or de-pulped beans) are placed in sealed stainless steel tanks with the oxygen displaced — often replaced with CO2 or simply allowed to depressurise as fermentation begins. Sealed fermentation runs 48 hours to several days, sometimes with added inoculants (specific yeast or bacteria strains).
Anaerobic fermentation produces compounds that don't exist in conventional processing — esters, lactic acid, sometimes alcohol-adjacent aromatics. The results can taste wildly different from anything else in coffee: strawberry candy, lychee, white wine, kombucha, rum.
Anaerobic is also where most processing experimentation is happening right now. Producers in Colombia, Costa Rica, Ecuador, and Panama are pushing the technique into territory that overlaps with natural wine or craft beer.
Tastes like: intense, sometimes funky, often divisive. Tropical fruit, fermented notes, "wild" character. Either you love it or you don't.
Good for: filter brewing as a single origin. Cuppings and tastings. Probably not your daily drinker unless you really love the style.
Classic examples: Colombian Cauca anaerobic naturals, Costa Rican Hacienda Sonora anaerobic honey lots.
How processing affects roast development
From the roaster's side, processing changes how we approach each bean. Washed coffees can handle longer roast development without losing their character — the cleaner sugar profile takes browning well. Natural coffees are roasted more conservatively because the fruit sugars caramelise faster and can tip into bitterness. Anaerobic lots get the most cautious treatment of all; the volatile fermentation compounds are easy to roast away if you push too hot.
This is why processing on the label is useful even if you don't know all the terms — it tells you what the roaster was working with, and helps you predict roast level. Most washed lots run from light-medium to medium roast. Most naturals stay light. Most anaerobics are roasted very light to preserve the fermentation character.
Matching method to taste preference
The easiest map:
- Want clarity, citrus, tea-like brightness? Reach for washed.
- Want sweetness, fruit, body? Reach for natural.
- Want balance and don't know what you like yet? Reach for honey.
- Want to be surprised, and you've already tried the other three? Reach for anaerobic.
Which Tone coffees use which process
Our core tones are mostly washed and honey-processed Central and South American lots, blended for consistency. Bright and High lean on washed components for their acidity; Dark and Low include naturals for body and chocolate notes.
The numbered series is where you'll find the more experimental processing — naturals, anaerobics, extended fermentations. The current №07 Panama Esmeralda Geisha is a natural-processed Geisha; previous drops have included a Colombian anaerobic and a washed Ethiopian Heirloom.
Frequently asked
Is one processing method "better" than the others?
No. Each method produces a different style of cup, and the "best" method depends on the bean's origin, the producer's skill, and what you want to drink. A skillfully-processed coffee in any method beats a sloppy coffee in a trendy method.
Why are natural-processed coffees often more expensive than washed?
They take longer to dry (2–4 weeks vs 1–2 weeks for washed), require more manual labour to rake and monitor, and have higher spoilage risk. The labour and yield cost shows up in price.
What does "fermented" on a label mean — is it bad?
All coffee is fermented during processing — it's intentional. "Fermented" on a label usually means extended or controlled fermentation, often anaerobic. It's not a flaw; it's a flavour direction. If you don't like wine-y or funky notes in coffee, look for washed lots instead.
Can I tell the processing from looking at the beans?
Sometimes. Naturals often look more uneven in colour and shape. Washed coffees tend to be more uniform. Anaerobics can show subtle colour shifts. But the bag label is more reliable.
Do darker roasts hide processing differences?
Largely yes. Past about a medium-dark roast, the roast character dominates and the processing-derived flavours fade. This is one reason specialty roasters keep most coffees on the lighter end.