Grading Coffee Beans
It is important to the global buyers of coffee beans, that the recognized grading standards apply to both size and quality, being relevant to the measure of the number of defects found present in a sample of 300 gram. Coffee beans are considered ‘normal’ when they produce an agreeable or satisfying product for the consumer. Defects, which may affect the flavour profiles of the ’satisfiable position’, reduce the overall grading of the ‘commercial lot’ from this position, and are measured by the number of defect beans and foreign matter present. A buyer, anywhere on the globe, places their trust on this system of measurement, backed-up by a sample in-hand, to ensure the ‘delivered lot’ is equal to the previously accepted sample. The defects, in increasing volume, become noticeable in solution and lead to unpleasant flavours. Hence a coffee company only grade 1 or 2 beans, becomes more likely to produce a more satisfying cup of coffee, (based on more positive flavour profiles present).
Defects in coffee beans are classified into five classes -
1 – Non coffee defects – stones, sticks, earthen particles
2 – Non bean defects – parchment, husks, dried cherry skin
3 – Irregularly formed beans – broken, processed nipped, shell beans, insect affected
4 – Irregular visual bean appearance – black beans, light green/immature beans, spongy, etc.
5 – Off-tastes – found only by cup testing, once roasted and brewed
While the world’s coffee growing regions vary in their classification terminology, the green bean purchasers have learnt their craft and are aware of the label system discrepancies and variables. The overall rule remaining is that higher grade beans produce a finer cup for the consumer – A very good reason to qualify your purchase from your supplier.
