Funky Phenolics!!

[Richee]

I received feedback from the brews I entered into the SOBA comp (Porter and APA). Both of them contained a phenolic aroma/flavour which let them down!! Good that I know this and now it gives me something to focus on. I’m interested in advice on how to correct this problem. From my research possible causes for the phenols are:

-Chlorophenols in municipal water supplies and residue from chlorine-based sanitizers.
-I don’t use chlorine based sanitizers I use Iodophor so I’m ruling this out.
-Pretty sure our water is low in chlorophenols?
-What about the interior of the hose I use to fill my HLT/mash tun, that’s probably made from PVC, I’ve taken to not using the hose to fill both now.


-Phenols extracted from the mash and during the sparge.
-Not oversparging, I stop the sparge when the runnings reach 1010.
-Not sparging above 170F, usually by the time it hits the mash tun I’m sparging at 74-75C.
-It’s recommended not to use alkaline water for the sparge, my normal tap water is pH 8 just on the alkaline side. Research indicates pH 6.0 being the upper cutoff here.

-Phenols derived from certain yeast strains that produce aromatic alcohols.
-I wasn’t using a Bavarian wheat yeast so could probably rule this one out. Although I was using an older Wyeast 1968 and American Ale II.


-Wild yeast contamination (particularly harboured within plastic based equipment).
-This is a possibility, I do keep all equipment very clean and most of my gear is stainless steel.

-Smokey phenols from smoked malts.
-I can rule this out as no smoked malts were used in the making of these beers.

Any advice would be most welcome

Richee

[Kieran Haslett-Moore]

Anouther possibility is stressed yeast, what are your pitching processes like?

Im told the problem you are describing was the most common one found during judging.

[Kieran Haslett-Moore]

Also I found that Idophor introduced all sorts of odd flavours into my beer, me, barge poll, idophor. Others love it tho.

[Sparky]

Similar result with my beers, am looking around and trying to get my head around "phenolic" aromas and flavours.

Phenolic appears to describe many mostly unwanted aromas and flavours that can be found in beer. Most confusing for me, I need to get my taste buds tuned.

Current plan involves making several changes to the process, noting them and then doing the same brew again after tasting with more changes if needed.

[Horace]

According to www.bjcp.org you can add a tiny amount of chloroseptic to a clean beer to recreate the taste ( suspect it is chlorine bleach). Find the study guide - it's quite handy./ interesting

Chloropenols are detectable in tiny amounts so wouldn't take much to change the perception of your beer.

From BJCP:

Phenolic
This is an aroma and taste often compared to Band-aids (tm), medicine chest or disinfectant.
Chlorophenols are particularly offensive members of this family with bleach-like flavors in addition to
the ones listed above. High levels of phenols are generally produced by bacteria or wild yeast, both of
which indicate a sanitation problem. Phenols may also be extracted from grain husks by overcrushing,
oversparging or sparging with hot or alkaline water. Chlorinated water and sanitizer residue are
possible sources of chlorophenols. Phenolic flavors are generally never desirable, the exception being
the clove-like, vanilla-like or slightly smoky flavors and aromas in Bavarian wheat beers and some
Belgian ales.

I'll try attach the whole thing

[Richee]

Yes the stressed yeast suggestion is a possibility. I use liquid yeast, propogate then pitch, saving abput 800 mL in steralised jars for later propogation and pitching. The age and viability of these may not be suitable!!! I'm going to be careful and only maintain a fresh stock (< 2 months). I will also try a batch using dry yeast.

Iodophor seems to work okay for me.
The BJCP info is good, I'm looking more closely at my alkaline sparge water? How important is this? Does anyone alter it??

Richee