What is the design principle of coffee flavor wheel? Get to know the new coffee flavor wheel

I guess you've all seen this master image at some point, and it's the Coffee caster's flavor wheel--the old version of the coffee caster, proposed by SCAA in 1995. The new version was designed by SCA (Speciality Coffee Association, SCAA and SCAE were officially merged into SCA in 2017) and WCR (World Coffee Research), and proposed in 2016 as an innovation.

Unlike the old version of the flavor wheel, which integrates biological, physical and chemical perspectives, the new version of the coffee flavor wheel, based on sensory science, re-adjusts the connection between aroma and taste, and the correspondence between defective flavor and positive flavor, further accelerating the coffee industry to establish a common language.

Old coffee flavor wheel

In 1995, Ted Lingle, part of SCAA, published the first version of the coffee flavor wheel (i.e., the old version of the flavor wheel that had been in use for more than 20 years) as a supplement to The Coffee Cup Handbook. Prior to this, coffee practitioners around the world had no consensus on coffee flavor and coffee communication language, which made fine coffee repeatedly blocked in the process of global promotion. Inspired by the wine flavor wheel, Ted Lingle combed the logic of flavor generation, starting from the essential characteristics of coffee, through planting, processing, roasting, extraction, sensory, flavor vocabulary classification, and finally sorted out the intuitive tools of span.

The old coffee flavor wheel integrates the common flavors of coffee, with the left wheel being the defective flavor and the right wheel being the positive flavor. Defective flavor refers to improper handling, transportation, storage or baking of raw beans, resulting in deterioration of protein and organic acids, resulting in adverse flavor spectrum. For positive flavor, take Aroma block of the right wheel as an example, we will find that the arrangement of aroma corresponds to the stage of aroma generation.(Enzymatic products are mainly produced in the planting and post-processing stages, caramelization and dry distillation reactions are produced after the first explosion and the second explosion respectively), coffee roasting process (Light baking to deep baking, aroma will vary according to enzymatic, caramelization and dry distillation reactions), degree of extraction (the order of aroma substances dripping from low to high, that is, the substances of enzymatic reaction will drip out the fastest), molecular weight of aroma chemicals (the smaller the molecular weight, the easier it is to volatilize, and the easier it is to be perceived).

New coffee flavor wheel

In recent years, innovative processing methods have blossomed, and post-production has focused on fermentation control, which makes the flavor presentation have more obvious fermentation feeling, even wine tonality. At that time, the negative impression of fermentation holding is no longer applicable to today. The coffee flavor round updated in 2016 has been adjusted to a general description such as Fermented and Overripe. Fermented does not understand whether the attribution is positive or negative flavor.

Although the old version of the coffee flavor wheel detailed the flavor into two rounds, the obvious difference between the defective flavor and the positive flavor misled the user's understanding of the positive flavor and the negative flavor to some extent, that is, only knowing that the flavor is opposite, it is easy to produce a black or white judgment.

SCA invited sensory scientists from WCR, Kansas State University and Texas A & M University, along with representatives of the coffee industry, to test and analyze hundreds of coffee samples from more than 13 countries and select the most representative 110 flavors to compile into Sensory Lexicon, which served as the basis for the new flavor wheel. However, tactile words that are not easy to measure, such as Astringent, Texture and Mouthfeel, have been eliminated by sensory scientists in the new version of the coffee flavor wheel.

Design principle of new coffee flavor wheel

The Sensory Dictionary integrates a large amount of coffee flavor data, and SCA invites Jean-Xavier Guinard and Molly Spencer to analyze deeper relationships and organize them into more intuitive reference tools.

Jean-Xavier Guinard and Molly Spencer independently tested 30 long-term coffee drinkers without professional sensory training and 40 coffee experts to objectively synthesize their perceptions of coffee flavor. Taking Fruit as an example, participants recognized that Blackberry, Raspberry, Blueberry and Strawberry were all included in Fruit/Berry flavor, while Berry was under Fruit.

Jean-Xavier Guinard and Molly Spencer used the AHC method of agglomerative hierarchical clustering to sort the data according to how close they were to each other, and to identify the largest categories. Then MDS multidimensional scaling was used to sort, and the multidimensional relationships among flavors were transformed into planar links.

relationship between classes

Through the new version of the flavor wheel, we found that floral, Fruity and Sweet are adjacent, that is, the connection is stronger, and the three are roughly equivalent to the defective flavor of the old version of the flavor wheel-Others are located at both ends, meaning that the respondents think that the two are very different.