How to Read This Guide
Grind size controls surface area and flow resistance. Finer grinds expose more surface area, extracting faster but resisting water more; coarser grinds extract slower with less resistance. Brew time and grind size are inversely linked — short contact time needs a fine grind, long contact time needs a coarse one.
The grinder calibration tables are sourced from Bluebird Coffee Roastery (South Africa), measured on factory-fresh grinders for filter brewing only. Espresso data comes from manufacturers and trusted reviewers. All settings are starting points — taste and adjust.
Extra Coarse
Looks like: Rock salt / peppercorns
Brew methods
Cold brew, cold drip
Extraction time
8–24 hours immersion
Flow behaviour
Minimal resistance; water moves freely around large particles, requiring long contact time to extract.
Coarse
Looks like: Coarse sea salt
Brew methods
French press, cupping
Extraction time
4 minutes
Flow behaviour
Low resistance; particles must stay above mesh filter pore size or fines will muddy the cup.
Medium-Coarse
Looks like: Kosher salt / coarse sand
Brew methods
Chemex, Clever Dripper, flat-bottom drippers
Extraction time
4–6 minutes
Flow behaviour
Moderate resistance against thick Chemex paper; pairs with bonded filter to slow flow for clean, even extraction.
Medium
Looks like: Beach sand
Brew methods
Automatic drip, Kalita Wave, siphon
Extraction time
4–6 minutes
Flow behaviour
Balanced flow; the safe default for percolation-based machines.
Medium-Fine
Looks like: Table salt / fine sand
Brew methods
Hario V60, AeroPress (standard), Moka pot
Extraction time
2–4 min pour-over; 1–2 min AeroPress
Flow behaviour
Higher resistance; flow noticeably slows. Moka pot range 360–660 µm.
Fine
Looks like: Granulated sugar
Brew methods
Espresso
Extraction time
25–30 seconds at 9 bar
Flow behaviour
High resistance is required to build pressure; flow is forced rather than gravity-fed.
Extra Fine
Looks like: Powdered sugar / flour
Brew methods
Turkish (cezve / ibrik)
Extraction time
3–4 minutes simmer, no filtration
Flow behaviour
No filtration; particles remain suspended and settle in the cup. Extraction is by heat and time.
Note on overlap: Ranges intentionally overlap because brew method, recipe, and grinder all influence the ideal setting. AeroPress is the widest-range device (320–960 µm), while espresso is the narrowest band — even a small drift causes over- or under-extraction.
Sources & Acknowledgements
Grinder calibration data courtesy of Bluebird Coffee Roastery (South Africa). Additional data from Honest Coffee Guide, 1Zpresso, Basic Barista, Baratza, Clive Coffee, Square Mile, Specialty Coffee Association, Counter Culture Coffee, Mahlkönig, and Specialty Batch.