The day before yesterday, at the last minute, I offered to give a class on the sensory perception of beer for my friend Scott Kerkmans, Instructor and Director of the Brewing Industry Operations Program at Metropolitan State University in Denver, Colorado (https://msudenver.edu/beer/faculty/).
Two things fascinated me about teaching the class.
The first was the opportunity to use Skype to bring me into a classroom 1700 miles away from home. I could run the Keynote presentation (that’s Mac’s Powerpoint) from my computer, and make comments on each slide as I presented them. I could hear the class as I did this, so I could answer questions and respond to their thoughts. It wasn’t as good as carrying out a class in person, where I can see the students’ reactions and clarify my statements as needed, but it worked! So you may see me doing this even more in the future…
The second was that, for the presentation, I looked into the question of the different flavors of beer, and how they engage the trigeminal system. This question led me to the Beer Flavor Map created in 2016 by Lindsay Barr, MS and Nicole Garneau, PhD to supersede the existing beer flavor wheels. Here they are holding up the map and celebrating its creation, from their twitter page (https://twitter.com/beerflavormap):
The purpose of this map is to give people into beer a vocabulary to describe their experiences. This standardization of vocabulary was the purpose of the original flavor wheel, made by Ann C. Noble at UC Davis for wine.
As with the wine wheel, I had to keep reminding myself that the Beer Flavor Map is not based on the biology underlying our ability to sense these flavors, but rather on an attempt to put similar flavors together and to give them names relating them to other flavors, for example “wheat” or “lemon.”
Yet what makes this map important, and different from all other maps and wheels that I have seen, is the inclusion of “mouthfeel” as a separate “place” (to continue the map analogy). By mouthfeel the mapmakers mean trigeminal sensations. Here is the “Mouthfeel” section of the map:
“Irritation” and “Afterfeel” are both functions of the temperature (TRP) receptors on the trigeminal nerve. “Effervescence” is primarily a function of the touch receptors on the nerve, though the relationship of “Effervescence” to “Carbonation” brings the temperature receptors into play as well—carbonation activates TRPV1, the “hot” receptors (note “Burning” under carbonation). “Body” is also a function of the touch receptors, but there can be confusion with the “Afterfeel” characteristics, which are a function of TRPV1, at least with respect to astringency and slipperiness.
So exciting to find a diagram for flavor descriptors that acknowledges the contribution of the trigeminal nerve to the overall flavor experience!