How many times in life would craft beer drinkers pay money to drink tainted Coors Light?! Apparently more than once as we had requests to do this event again.
Jered McGivern is a professor of microbiology at Lakeland University (Plymouth/Sheboygan). He approached me with some Siebel Institute sensory tasting kits (aka flaws and extreme flavors). I have done the facilitated version of this class several times as a BJCP judge and having attended the World Brewing Academy . I suggested that I accept the viles only if (a) we could use it as a fundraiser for his Europe Travel Course this summer and (b) he helped me facilitate the event. Obviously, Jered is a standup guy and we proceeded.
Ticket sales at first were nothing for the first month, but as the date approached we complete sold out of the advance session (which also included the basic session). We ended up faciliatating 24 different people through this tasting. I like how Jered "school themed" this by calling each workshop Beer Flaws 101 and 201.
We took roll-call to kick off the event then Jered gave a brief 15 minute lecture on smell, taste and these flaws. Coors light was dosed using a fancy pipette (watch the video here). Most of these sensory trainings standardize on using 3 times the tasting threshold for that particular compound. (see the charts). The basic training session we tasted:
4. Isoamyl acetate (found in bananas and hefeweizens)
5. papery (trans-2-nonenal)
The two core flaws are Acetaldehyde and Diacetyl which show up for immature fermentations, incomplete fermentations or even infected tap lines. Acetaldehyde comes across as a green apple flavor/aroma. All beer goes through a stage that creates this, but the yeast always cleans it up in a mature fermentation. Diacetyl is created by the breakdown of acetolactate which almost all beer create but it is very prevalent in English ales and most lagers. It is described as a buttery flavor and is, in fact, the exact compound used to flavor oils and sold in movie theaters as popcorn butter. (bacteria-produced diacetyl-flavored oil doesn't have the same ring as movie theater popcorn butter, does it?)
After taking a 10 minute break we came back and tried these compounds:
1. Isovaleric Acid (old cheese, usually from old hops)
2. Geraniol (flowers, usually from hops high in certain oils)
3. Peat like (clean dirt)
4. barnyard (4-ethyl phenol) (horse blanket)
5. Butyric acid (vomit)
inventors brewpub advance beer flaws
Here was another slide that Jered used in his presentation. It shows how closely related many compounds actually are and it drastically changes the taste threshold detection as well. In this case these are phenol-based compounds.