The role of cupping in specialty coffee
The popularity of coffee is still growing, but the definition of what makes a ‘good’ cup of coffee is complex.
It might be tempting to think that it is largely subjective, with so many types of coffee grown around the world, so many processes to consider throughout the value chain, and so many local and national preferences.
However, the sustainability of the industry depends on the value placed on certain types of coffee. Local economies can thrive or fail, depending on the desirability of their crop.
The growing preference for ‘specialty’ coffee, sold at a premium price, is making the quality question even more critical. The ability to distinguish specific characteristics that make some crops more desirable than standard commercial coffee has become a major consideration over the last 20 years.
Physical characteristics of the bean or cherry are not good indicators of flavor in the cup, so how is this important choice to be made?
Cupping, the process of grading coffee quality based on a tasting protocol, is often the basis of quality decisions.
Is it, however, reliable when the final judgement is made by consumers who have rarely seen roasted beans and almost never the green beans?
The evolution of coffee tasting
Although instruments have been created to analyze the quality of coffee cherries and beans, our senses remain the only practical test of flavor.
Less than 20 years ago, each coffee producing country had its own system for grading coffee. Taste wasn’t always included in the evaluation, so there was widespread confusion about what ‘quality’ meant.
The search began for processes that could be adopted for a harmonised world-wide system to evaluate coffee quality. Alongside our growing passion for specialty coffee over the last 15 years techniques that use our senses to assess coffee quality and flavor have developed.
The Specialty Coffee Standard is now widely used to define green coffee that can be considered ‘Specialty Grade.’
The Specialty Coffee Association (SCA) Cupping Protocol is used to grade specialty coffee. Its ten-point profile is more comprehensive than previous methods and it is used generally for Arabica coffee, rather than focusing on a single country of origin.
Cupping as a measure of coffee quality
Using a new cupping protocol that focuses on the sensory profile of coffee demands a new generation of coffee professionals who are trained in sensory assessment.
Tools such as the Coffee Wheel and ‘Le Nez du Café’ kit have been developed using a range of reference aromas to standardize the approach. Courses have also been created to develop taste-assessment skills in addition to sensory skills.
All of this has now been included in a widely-used six-day course and examination for ‘Q Graders’. Importantly, this has created a recognized language to describe coffee quality. This terminology has now been grouped in categories and structured to produce a Coffee Taster’s Flavor Wheel.
Inevitably there are now online tools and apps based on these approaches to support collaborative cupping and to create visual representations.
The cupping protocol
The standardized approach can be divided into two parts; sample preparation and sensory assessment.
The conditions for roasting, grinding and brewing the coffee beans are set and ten sensory assessments are made.
First, quality scores are given for fragrance/aroma, flavor, after-taste, acidity, body, balance, uniformity, lack of defects (clean-cup), and sweetness. Any defects are identified and an overall assessment is included in a total score.
Second, intensity ratings are given for attributes including fragrance, aroma, acidity and body.
Finally, more subjective descriptive terms are used about fragrance, aroma, flavor, aftertaste, acidity and body.
Cupping as a tool for decision-making
Cupping is the only approach to quality commonly used throughout the coffee value chain, from tree to cup.
Other measures, such as the number of defects or roast degree, are useful for specific stages along the chain but are only helpful as a quality measure when they are correlated with cup flavor. These measures certainly can’t answer questions about which is the ‘best’ coffee when cost of production is also a consideration.
The specialty coffee industry increasingly uses the cupping ‘Final Score’ as an indicator of value. Other than the fermentation method, this approach is only reliable when other parameters are consistent, on a single farm, for example. Cupping can therefore be a valid tool for helping to choose the location of a coffee farm, assessing the quality of coffee from neighbouring plantations.
It is more typically used to make decisions after harvesting concerning the variables involved in processing, fermentation and drying. Importers and roasters will also use tasting to value the beans.
The effectiveness of the method depends on the availability of cupping laboratories and qualified cuppers throughout the value chain. While sensory skills and processes can be developed though the Q Grader training course, it is only through experience that cuppers can develop their own mental reference library of coffee profiles and characteristics.
The full cupping protocol can be time-consuming, so large volume green coffee traders who do not focus on the high-end specialty market will use a ‘rapid’ method. These might be company-specific and won’t give comparable quality measures.
Dark roast and espresso-based drinks can’t be assessed using the same approach used for green beans, so roasters and retailers have developed their own tasting protocols.
Other parameters in coffee quality
The flavor profile must be the ultimate quality parameter for coffee. Physical and chemical characteristics alone are not reliable indicators of quality.
However, coffee cherry ripeness is known to be an indicator of quality that can be assessed using photographs of cherry colour throughout the ripening process, although this is normally variety-specific.
Sugar content or ‘brix’ (°BX) can also be used to determine ripeness and suitability.
The number of beans damaged during the pulping process can also be used as a measure.
Acidity, or pH, is also a good indicator during the fermentation process in pulped coffees, although this can vary, depending on conditions.
Bean temperature and moisture levels can also affect the final flavor.
Sensory assessment of coffee quality will continue to evolve and more reliable global tools for consistent cupping results will be developed.
Training cuppers with a revised Flavor Wheel will be a priority for coffee producing countries, ensuring consistency of quality decisions throughout growing and processing.
It will certainly need be extended to apply to Robusta coffee.
Above all, improved understanding between sensory experts, flavor chemists, and other scientists will improve our understanding of the complex business of assessing coffee quality in years to come.
* “Flavor as the common thread for coffee quality along the value chain” by Mario R. Fernández-Alduenda, from the Coffee Quality Institute, USA, is taken from: Lashermes, P. (ed.) Achieving sustainable cultivation of coffee, Burleigh Dodds Science Publishing, Cambridge, UK, 2018 (ISBN: 978 1 78676 152 1; http://www.bdspublishing.com)
By Mario R. Fernández-Alduenda, The Coffee Quality Institute
Excerpted from The Sustainable Cultivation of Coffee