[A]fter more than twenty years as the go-to tool for evaluating coffee, the Coffee Taster’s Flavor Wheel has received its first update by the Specialty Coffee Association of America. Though, really, update is too soft a word for the changes. The wheel was gutted, knocked down, and excavated down to its round foundation. The reconstructed wheel was built on the same research that created the Coffee Lexicon, a scientific instrument being used by World Coffee Research to develop the next generations of coffee plants. The new wheel is that project’s most significant document to be aimed at the coffee industry’s non-scientist members.
Starting with its design, the new wheel shows the update is a stark change. Where the old wheel was actually two wheels (one describing faults and taints; the other, tastes and aromas) the new poster drops the defect side and presents a single wheel focused on flavor. The wheel even ditches the divide between tastes and aromas. Instead of five rings of categories, it has three: nine base categories, sixteen groups, and eight-six attributes. The old wheel had just fifty-two attributes (counting just the outside ring on each side). Not only were attributes added, some were replaced. For example, the old wheel included apricot and blackberry in the berry-like group. The new wheel has blackberry, raspberry, blueberry, and strawberry. Similarly, burnt is no longer an attribute, but there is a burnt group that includes smoky, ashy, acrid, and brown, roast.
The flavor descriptions come from the Coffee Lexicon, which was developed for World Coffee Research by a team at Kansas State University’s Sensory Analysis Center. It took that team more than a year to identify and evaluate 111 attributes, including flavor and textures. Peter Giuliano, a senior director at the SCAA, calls it the biggest study ever done on coffee flavor. “Halfway through that project, it became clear that this research underpinned what the flavor wheel was supposed to be,” he says.
The old wheel, created in 1995 by a small team lead by Ted Lingle, was a watershed moment for coffee. Giuliano calls it “paradigm busting,” because for the first time there was a common tool and language to evaluate coffee. Nothing about the development of the wheel was scientific. Even the coffee literature it relied on was informal and thin. Giuliano points out that only ten documents were used as sources for the wheel. That was all they had, along with the deep experience of the team. There was nothing else to pull from, and that they created a tool that’s supported the explosive growth of the specialty coffee industry for two decades is even more remarkable considering these limitations.
With the Coffee Lexicon offering, for the first time, a scientifically validated approach to describe flavor, the SCCA moved to create a new wheel. The lexicon, as robust as it is, is like an operating system: powerful but not intuitive, even for pros. The wheel is like an app, and the SCAA asked the Food and Science Technology Department at the University of California, Davis, to help them design it. More than seventy professional tasters and sensory analysts took part in a study that plotted the different attributes, showing how the tasters sorted them. This created the categories and groups that organizes the wheel.
In many ways, this hard-science approach validates a lot of the decisions made on the original wheel. For instance, Lingle and his team placed the groups syrup-like, chocolate-like, and vanilla-like next to each other. The UC Davis research plotted those with each other, and the new wheel has vanilla, brown sugar, and cocoa grouped together. (The professional cuppers likely thought of flavors in terms of the old wheel, so the groupings might be the old timer’s looks showing up in the new generation.)
An element of the old wheel that has been left out is the interior ring, which, for aromas, included enzymatic, sugar browning, and dry distillation. Giuliano says these rings were attempts to diagnose where the attributes originated, but with little or no scientific research to draw on, it was informed speculation. Because WCR’s research hopes to pinpoint the molecular compounds that create coffee’s different attributes, this information may be included in future iterations. Likely though, it will join the information about defects and taints in other SCAA materials, leaving the Coffee Taster’s Flavor Wheel a purely descriptive tool.
The SCAA is revamping its cupping curriculum, training materials, and other literature over the next year to bring everything in line with the new wheel. Posters of the wheel are available on the SCAA’s website in February.
—Cory Eldridge is Fresh Cup’s editor.