Kyle & I have been blessed as far as our brewing disasters are concerned. Only once have we encountered the distinct flavor of phenol and we weren't sure what it was at first.
Kyle and I had just sat down to enjoy what we had waited patiently for, a new home-brew to devour and hand out to our family and friends, another bragging point, notch in the belt… however as we both toasted to one another and tilted the pint glasses toward our maws, we both withdrew quickly, sharing a knowing glance.
Now we didn't know what was wrong at first, just that whatever it was it wasn’t right. Very distinct band aid flavor was present - which after doing some trolling of the brewing forums we discovered was phenol our band-aid medicinally scented foe.
Phenols are very commonly described as medicinal, band-aid when described in negative terms and smokey, clove-like when described positively.
What can cause this aroma?
Some belgian yeast strains
Over chlorinated water
Cholorophenols are generally thought of as the medicinal unwanted flavor/aroma, while Bromopheonls are generally those described as smokey or clove-like within the certain belgian styles.
Acceptable Styles for Phenolic Tastes: Wheat, Some Belgian Styles
So in short - swirl your glass, smell your beer if it doesn’t smell right - have a sip or three anyway. Savor the mistakes along with your successes - because the bandaid flavor is something every brewer gets to know. Your shelves may be a bit lighter once you throw out the brew but your brewing palate and skill set will thank you for it.