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.
Coffee Blending – ‘A Science of Flavours’
Just like an artist, with tubes of paint and pallet can create all the subtle colour changes of the spectrum, so too can coffee blenders have a similar ‘tool base’ to create shades of flavours. Blending is a very serious business, where blend recipes hold high value and the science is exacting. Though the majority of coffee comes from the same varietal Arabica, with lesser volume from other choices, the flavour and structural characteristics inherent within each bean, from different global locations, vary dramatically.
We all acknowledge that the common grape varietal Chardonnay, grown in France, South Africa, Australia or California, will produce obvious and diverse finished wines, though the varietal is common. This is due to soil, micro-climate, altitude, season, temperature, and rainfall. Then of course, there is the makers mark. So too, these variables are highly applicable to coffee production around the globe.
Characteristics such as body, acidity, fruit and other variable flavours, along with size, density, and colour are also relevant to the coffee bean. These diverse characteristics present the blender with thousands of blend options, both good and bad, as they are combined together. The challenge in creating successful blends is in using all the available characteristics and applying them in a balanced and harmonious manner, creating a bigger and better flavour experience in the cup. While single origin coffee is an interesting beverage option – to note and enjoy one location’s individual characteristics – it is important to understand that the global market is driven by the consumers palate, which demands the best possible coffee experience. Blending can achieve this objective.
Coffee blenders diligently work with the variables of each season and each shipment of beans, to maintain a consistent and reliable product. There is no doubt that a blended coffee brings forward a richer coffee experience and is critical to the success of espresso infusion.
