Problems arise when you take a specific yeast out of its sweet spot. Raise the temperature too high, and your cooler temperature loving lager yeast could yield banana flavors (esthers) or you could end up with the dreaded black sharpie or plastic-y flavor (phenols). Running beyond the desired temperature range can also yield up ‘hot alcohols,’ as the yeast quite literally, goes nuts. That’s not to say that these bi-products are always bad; the smokey and clove-like (phenols), as well fruity (esthers) flavors of German hefeweizens are derived from them.
But when esthers serve up bananas, you’re not tasting banana—you’re tasting what tells your brain you think you’re tasting banana.
That from one of SCHB’s titans, Scott Ruddich, who is unusually absent tonight. After launching a plan with a friend to start a brewery someday, he began attending The Keystone Hops and then, SCHB, where he dove into the seemingly paradoxical nuances of beer.
“They both have their advantages,” he says, pointing out that the more social Keystone Hops, with larger meetings, offers a high amount of general feedback, while Stoney Creek is much more technical in their feedback.
He had to apply such an examination to one of his own beers at a previous meeting that saw members squaring off against each other with two homemade brews apiece.
On that day, Ruddich’s sharpie heavy Tripel fell out of the gates against Mike Urban’s refreshingly crisp Kölsch.
Ruddich says he was felled by contamination caused by not having his wort at a high enough temperature when he pitched his yeast. The weaker fermentation activity resulted in less carbon dioxide being put off, which can, if the fermentation goes long enough, “clean up” the beer by blowing off unsavory elements—tell that to anyone who still thinks beer isn’t refined.
Though his beer that day offered an obvious example, he stresses how important it is to be able to recognize when a beer is off, whether it’s just plain bad or—important for contest entry—if it has fallen out of the desired range for a particular style.
“Even though we have our formal recipes, it’s good to bring a lot of stuff with known flaws, so they can recognize and prevent the same errors in their brewing,” he says.