Coffee Bean Classifier
Turn green-coffee measurements into a predicted cup, an origin-calibrated roast plan and a risk check before the first batch goes in.
Green Lot
Heirloom landraces, small dense seeds, jasmine and stone fruit. Switching origin loads a typical lot for it.
Ethiopian and Yemeni landraces: small, dense, floral, irregular screens.
Mucilage removed before drying: clean, bright, origin clarity, loud first crack.
Light roast dropped shortly after first crack to keep origin character.
For this origin, 1600 m counts as mid and 1900 m as high-grown.
Free-fall bulk density. Sound lots from this origin: 710 to 760 g/L.
Typical screens for this origin: 14 to 16. Size itself does not change the cup; uniformity does.
Ethiopia (Yirgacheffe, Guji, Sidama) · Heirloom / landrace · Washed
- Trade grade
- Grade 1 to 2 by cup and defects; size is not graded
- Altitude
- 2000 mHigh-grown
- Density
- 735 g/LHard · typical for origin
- Crop state
- Stable10.8% / aw 0.53
- Acidity type
- Citric, bright
Predicted cup
Expected in the cup
Phase plan
- 01ChargeHigh · 195–205°C
Dense, high-grown seeds need thermal momentum so the core keeps pace with the surface.
- 02Drying4:30–5:15 · to 160°C
Front-load the energy: dense seeds need a strong drying phase or the roast stalls later.
- 03Maillard3:30–4:15 · to 196°C
Water activity is in range; browning progresses predictably from yellowing to first crack.
- 04First crack196–201°C · loud and distinct
Clear, audible first crack: high internal pressure gives a reliable cue.
- 05Development1:25–2:23 · DTR 15 to 20%drop at 202 to 211°C · Agtron 65 to 78 · light roast
Short, clean development: drop 6 to 10°C after first crack to keep origin character.
- 06Rate of risePeak 18 to 22°C/min
Aim for a smoothly declining rate of rise from the peak to the drop. Avoid a crash after first crack; a stalled roast bakes.
- 07AirflowMedium at charge, rising
Dense seeds tolerate moderate airflow from the start. Moderate chaff; open the airflow from yellowing. Increase airflow at first crack to remove smoke.
Bean-probe values for a classic drum roaster at 60 to 70% batch load. Treat the temperatures as offsets from your own machine's baseline; the phase ratios and the order of decisions transfer directly.
What can go wrong
- Uneven roastLoworigin arrives irregular
Lot indicators
- Moisture and water activity sit in the stable window; the lot will roast consistently.
- High-grown for this origin (1900 m and up): dense seeds, lively acidity.