Detecting a strain of hops with your palate is one of those skills that elude even Master Cicerones. (Only Daredevil can do shit like this, please don’t front.) Detecting the types of fruits in a hazy IPA? Totally doable. Detecting whether or not a tap line is dirty? If a beer has been stored or packaged incorrectly? You can train yourself to do this, but you’re going to need to ruin your beer.
I’ve been using quarantine to improve my palate and general beer knowledge, or at least that’s what I've been telling myself to justify how I’m somehow spending more money on beer per month than gasoline. So I decided to perform an experiment used by Cicerones to detect off-flavors.
Aside from beers to skunk and desecrate, there were other ingredients I would require: butter extract and a green apple. These would come in later, because the first variable I needed to worry about when ruining my beers was my cat. I planned to leave a covered glass and a half-empty can full of a light lager in my apartment for 24 hours—in order to test the effects of light and oxygen on beer—but where could I possibly put them where she would be at a tactical disadvantage should she decide to investigate? This was the most complicated part of the experiment.
I poured a can of Tecate into a glass, affixed a paper towel to the mouth with a rubber band, and found a sunny spot on my desk where this guy could marinate or do whatever the fuck beer does when it goes through light and temperature changes for 24 hours. The remainder of the can was hidden on a kitchen countertop. I crossed my fingers and hoped for zero cat-related spills.
Miraculously, both beers were still upright the next morning. I immediately refrigerated them both to get to a normal serving temperature. After an hour, it was taste test time.
A freshly opened, 24-hour chilled can of Tecate would be my Control Beer. Imagine, for a moment, the idea of using Tecate as a palate cleanser. I’ll wait. (While you ponder, also consider that if you’re trying this at home, nearby water and/or the use of a spittoon is advised.)
Test #1: Acetaldehyde
Tecate has notes of green apple. Sniff the apple and then a glass of the Control Beer: Those waxy, Jolly Rancher-type notes are acetaldehyde. It’s a natural thing created by yeast during fermentation. If the brewer doesn’t complete the fermentation process (usually in lagers) this is the result.
Test #2: Diacetyl
Take an eyedropper full of the butter extract and squeeze three drops into another glass of the Control Beer. The beer should now smell like butterscotch—the same flavor of diacetyl,another common yeast byproduct that’s usually reabsorbed by yeast. A short diacetyl rest—a.k.a. allowing a beer to hang around at a few degrees higher than fermentation temperature—reduces those buttery flavors. This also can occur in dirty draft lines—if you’re having beer from a keg at a bar and didn’t order a mouthful of movie butter popcorn, they done ya dirty, because diacetyl is an ingredient in both.
Test #3: Trans-2-nonenal
Pour some of the beer left in the darkened or dim location. This is what happens when beer gets oxidized. The beer dies like a Lovecraftian horror. It’s flat, no carbonation. It should taste like cardboard. It should smell like the morning after a sorority party. It tastes like vomit. It smells like Karen needs to get someone to clean this shit up. Poorly packaged canned beers have this flavor profile.
Test #4: Lightstruck beer
She didn’t knock it over, but did the cat get to the lightstruck beer? Certainly smells like she did: There’s a heady aroma that suggests litterbox… or maybe it’s armpit? UV rays cause a reaction in the beer, essentially turning the sun into a Skunk Ray. You’ll taste this most commonly in beers that are packaged in clear or green bottles.
Test #5: Finish your Control Beer
I told you it would be a palate cleanser. You’re welcome.