Washed
Cherry pulp removed, bean fermented briefly in water, then washed clean.
Cup: bright, clean, acid-forward, linear.
Educational
Understanding what's in the cup.
Fermentation school.
Every coffee has a base process. Anaerobic fermentation is not a fourth type — it is an over-layer that can sit on top of any of them. What follows is the full stack: the three base processes on which every lot is built, the anaerobic layer we dial on top, and the co-ferment innovations re-writing what specialty coffee can do.
The short version: a "process" describes how the cherry leaves the fruit. An anaerobic hold describes what happens before that — and the two are not alternatives. A washed coffee can be anaerobic. A natural can be anaerobic. A honey can be anaerobic. Each combination tastes different; each is a deliberate choice at the farm.
Tier 01
The three base processes
How the coffee leaves the cherry. Every lot — ours, anyone's — starts here.
Natural
Cherry dried whole in the sun. Fruit ferments with the bean inside.
Cup: fruit-forward, heavy body, wild, low clarity.
Honey
Pulp removed, mucilage left on the bean to dry. Named for the sticky texture.
Cup: middle ground — structure plus sweetness.
Tier 02
The anaerobic over-layer
Sealed-environment fermentation applied before the base process. Not a replacement — a layer.
Anaerobic Washed
Cherry held in sealed environment (often 72h) before the usual wash.
Shift: cleaner than a natural but layered with florals, tropical esters and a wine-like depth the washed base never reaches alone.
Anaerobic Natural
Sealed-environment hold, then dried as a natural.
Shift: the most fermented profile — stone fruit, port, balsamic, cooked cherry and warm spice, almost liqueur-like in density.
Anaerobic Honey
Sealed hold, partial-pulp removal, mucilage-on drying.
Shift: amplified sweetness over structured body — honey, peach, caramel and a subtle vinous tension on the finish.
Anaerobic is a dial, not a choice. The same lot can be run three ways from the same tree.
Tier 03
Advanced fermentation variants
A growing family of research-grade techniques. Each one introduces a deliberate variable — a microbe, a gas, a temperature swing, or an added substrate — on top of the anaerobic layer.
Yeast anaerobic
A selected yeast strain (e.g. Saccharomyces cerevisiae) is inoculated into the sealed environment. Predictable profile, repeatable lot after lot.
Koji anaerobic
Koji mould (Aspergillus oryzae, borrowed from sake brewing) is introduced during fermentation. Breaks down proteins; adds umami depth and long, sweet finishes.
Carbonic maceration
Environment purged with CO₂ rather than simply sealed. Intracellular ferment inside whole cherries. Borrowed from Beaujolais.
Lactic fermentation
Pre-inoculated with lactic-acid bacteria (Lactobacillus). Creamy, yoghurty body; a softer acidic frame.
Thermal shock
Controlled hot/cold cycling during fermentation. Stress activates distinct metabolic pathways — and distinct volatile profiles.
Fruit & substrate
Fruit pulp, juice or wine lees added to the environment — melon, peach, mango, passion fruit. Foreign sugars feed the microbes and graft new esters onto the cup. The most expressive, most divisive variant.
From green to cup.
A roast is time plotted against temperature. Every decision — where to slow the rise, when to drop — is a choice about which flavours to hold and which to burn away. Here is the curve we run, and the three zones it passes through.
Zone 01
Drying
Bean loses its moisture. Grass-like aromas burn off. Thermal momentum builds for what's next.
Zone 02
Maillard & caramelisation
Sugars brown. Amino acids react. Most of the flavour complexity in the final cup is built here.
Zone 03
Development
After first crack — where flavour is balanced, acidity is tuned and body is set. With heavily fermented lots we run a longer, lower-temperature development to preserve the volatile esters the environment worked so hard to build. The drop is a judgement call.
The dial-in.
Three variables. You change one at a time. That is all there is to brewing well — the rest is taste, time and patience. Our favourite recipes live at the end of Our Story; here is the reasoning behind them.
Ratio
Grams of coffee to grams of water. 1 : 16 is a starting point for pour over. Stronger? Lower the ratio. Weaker? Raise it.
Grind
The surface area water can touch. Finer = more extraction, more body, more bitterness risk. Coarser = cleaner, lighter, risk of sourness.
Time
How long water is in contact. Adjust with grind, not with stopwatch. A 3-minute pour-over that tastes sour was probably ground too coarse, not brewed too short.
If a cup tastes sour, extract more (finer grind, hotter water). If it tastes bitter, extract less (coarser, cooler, shorter). One variable at a time.
How we taste.
A cupping is a controlled-environment tasting. Every coffee is ground the same way, brewed the same way, at the same time. The noise of technique is removed so the coffee itself can speak. Here is the protocol we run on every arrival.
1 : 18
Grams of coffee to grams of water. The SCA cupping ratio — the one we run every morning. Typically 12 g of coarse-ground coffee to 216 g of 93 °C water, five cups per lot.
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01
Grind & smell
Nose on the dry grounds. First impressions — sweet, green, fermented, muted?
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02
Pour
Hot water at 93 °C, 1:18 by weight. Steep four minutes, a crust forms on top.
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03
Break
Stir the crust, lean in. The burst of aroma is the most concentrated the cup will ever smell.
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04
Skim & slurp
Remove floating grounds. Slurp aggressively — aeration spreads the liquor across the palate.
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05
Score
Rate fragrance, flavour, aftertaste, acidity, body, balance, uniformity, clean cup, sweetness, overall. SCA 100-point.
The spoon
Brass cupping spoon →
Weighted, deep-bowl, SCA-standard. Ships free in every Anaerobic welcome kit — also available in our accessories shelf.
The scorecard Free cupping sheet (print-ready) →SCA 100-point format, five cups per lot, defect grid included. Print, clip and score.
These 42 compounds are what controlled anaerobic fermentation layers on top of a traditionally-processed coffee — not a replacement, a supplement. The full wheel lives in Our Story · Chapter 4.
Words to know.
Terms we use across Anaerobic — on labels, on the site, in conversation. Not exhaustive. Useful.
- Altitude
Elevation of the farm, usually m.a.s.l. Higher altitude slows cherry maturation → denser beans → more complex flavour.
- Cherry
The fruit of the coffee tree. The bean is the seed inside.
- Cupping
Standardised tasting protocol — see Module 04.
- First crack
Audible cracking during roast as the bean expands and fractures. Marker for the start of Zone 3.
- Lot
A traceable batch from a single farm, day, process and drying method.
- Mucilage
Sticky, sugar-rich layer between the cherry skin and the bean. Honey keeps it on; washed removes it.
- Process
How the cherry leaves the bean — washed, natural, honey. See Module 01.
- Single origin
Coffee from one farm or cooperative, not blended across origins.
- TDS
Total dissolved solids. Measured with a refractometer; tells you how much coffee made it into the cup.
- Varietal
A cultivar of Coffea arabica (Bourbon, Typica, Gesha, Sudan Rume, Heirloom…). Like grape varieties for wine.
- Yield
In brewing: extraction yield, the percentage of the coffee dissolved in the water. 18–22 % is the target window.
- Washed / Natural / Honey / Anaerobic
See Module 01. The first three are base processes; anaerobic is an over-layer that can be applied to any of them.
You've read the manual. Now choose a door.
Three ways to go deeper — the working notebook, the long-form chapters, or the roast itself.
01 · Journal
Dispatches from the farm and the roastery.
Long-form essays, producer interviews, harvest notes and the occasional failure. The working notebook behind every lot.
Read the Journal
02 · Our Story
Seven chapters on how Anaerobic was built.
From first curiosity to forty-two compounds. The long version of why we do this — written like a magazine feature, not a catalogue.
Read the story
03 · Shop
Every coffee, tagged by process and tier.
Filter by anaerobic layer, origin, altitude, varietal. Start wherever your palate takes you — the guide is only useful if it ends in a cup.
Shop the roastBetter knowledge, better cup. Start with a bag →