Posted on April 28, 2017
The Color of Coffee Can Display its’ Flavor Profile
The color of a coffee bean can say a lot. Different colors come from different roast durations. Minute differences in roast can have outsize effects on coffee’s flavor, acidity, body, and aftertaste1 So, determining the exact color of a coffee bean after a roast can tell a manufacturer a great deal about what the coffee will taste like.
For the average coffee drinker, telling a coffee’s attributes from the color of its roast is a neat party trick, It’s a way to show off to their friends that they’ve read about the eight strictly defined SCA color grades, Very Light to Very Dark—a way to build up self-esteem. In short, the stakes are low. For a manufacturer, however, the SCA color grades are their brand. It’s why people buy their coffee. Keeping color consistent is essential to retaining customers. In short, the stakes are high.
SCAA Scale Is Used to Classify the Colors of Coffee
That’s why coffee roasters rely on the SCCA scale to rate the color of their beans during the production process. By matching the color of a bean to a printed sample, they can determine within a reasonable margin of error whether each batch has been properly roasted.
This method has its drawbacks, however. To start, exact color matches are difficult between textured materials. The differences in surface texture of coffee beans and vinyl printouts affect human color perception. Also, human beings are inherently subjective at assessing color. Color perception differs between different observers, or even between the same observer at different times of day. Sample preparation and measurement can cost manufacturers valuable time if they are not done properly. Saving data from tests takes up even more time, as it must be initially recorded and then entered into one or more data storage systems.
Spectrophotometers Can Measure Coffee on the Agtron Scale
To correct this, many coffee roasters have turned to using the HunterLab ColorFlexEZ Coffee spectrophotometers to determine the color of their roasted beans. These instruments measure color with extreme precision and can be delivered programmed to display their results according to the SCAA scale. HunterLab even invented the HCCI (Hunter Color Coffee Index), with input from roasters worldwide, to improve upon the SCAA scale. By using instrumental measurement, they eliminate the subjectivity inherent in human observers. The data can be transferred easily from these machines to a central location, such as a hard drive or the cloud. The machines take fast, reliable measurements, and samples can be quickly prepared, and a single measurement can report the SCAA number, Roast Classification, and HCCI number.
Full article with photos available here: