Methodology
Methodology
The protocol used to evaluate coffee roasts and produce RoastEval reports.
Scope of Evaluation
RoastEval evaluates the quality of coffee roasting, not the intrinsic quality of the green coffee.
An exceptional coffee can be poorly roasted, and an expertly roasted coffee cannot completely overcome limitations in the green coffee. RoastEval therefore focuses exclusively on assessing the roast itself.
Coffee Preparation
Coffee is evaluated between 1.5 and 3 weeks after roasting, allowing flavours to stabilize while preserving aromatic complexity.
Coffee is ground relatively fine in order to maximize extraction and fully expose roast characteristics for evaluation.
Brewing water is maintained at 100°C. Its mineral composition is standardized to the following targets:
- 150 ppm magnesium (Mg)
- 25 ppm bicarbonate (HCO₃)
Brewing Protocol
RoastEval uses a modified cupping protocol designed to emphasize brewing evenness and maximize the expression of roast characteristics.
- Grounds are stirred as water is added to ensure even saturation.
- Coffee steeps for approximately 10–25 minutes.
- Each sample is evaluated at approximately 12, 17, and 22 minutes as the coffee cools.
Roast Defects
Under-Roasting
| 5 | No noticeable under-roasting. |
| 4 | Slight lack of clarity or character without obvious defect flavours. |
| 3 | Underdeveloped bitterness (“metallic”). |
| 2 | Vegetal or brothy character accompanied by underdeveloped bitterness. |
| 1 | Wheaty or corny. |
| 0 | Grassy or green. |
Over-Roasting
| 5 | No noticeable roast-derived flavours. |
| 4 | Slight flattening of acidity with subtle fibre-like flavour and slight dryness. |
| 3 | Mild caramelization with bittersweet chocolate or burnt sugar notes. |
| 2 | Heavy caramelization with pronounced dryness. |
| 1 | Ashy or smoky. |
| 0 | Carbonized. |
Overall Roast Score
The overall RoastEval score reflects the combined assessment of under-roasting and over-roasting. Coffees receiving the highest scores exhibit neither under-roasting nor over-roasting, allowing their unique origin characteristics to be expressed with maximum clarity.
Report Generation
Every RoastEval report includes observations on under-roasting, over-roasting, and an overall assessment of the roast.
Reports may be published publicly or kept private at the submitter's request. Public reports contribute to RoastEval rankings.