Phenol/Chlorophenol Smell and Taste

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SOB_OCDAVE

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Before I begin I want to state that I have read every post on the web site about pheholic off flavors. I am also a 10+ year homebrewer of all-grain beers and very methodical/precise with my techniques. With that being said:

Recently I have been experiencing a metallic, off-flavor in my beers. Never had this problem before, so I am completely confused. I can smell the off flavor and taste it and it really bothers me when i burp and the smell permeates my mouth and sinuses! Yuck...

I have had professional brewers sample my beers and they say its chlorine related. I use water from Watermill Express, a 12 step process that removes everything from the city water supply and leaves almost nothing but high quality drinking water. There is a trace of Magnesium (.1 mg/L) and Sodium (1 mg/L) with a 5.5 ph. NO CHLORINE SMELL OR TASTE.

I sampled my last batch (spiced pumpkin ale) through each transfer from kettle to primary, from primary to secondary, and from secondary to keg. No phenol or other off-flavors detected. I used a closed transfer from corny to corny with a C02 tank and everything on the cornies and hoses were stripped down and cleaned with oxiclean and sanitized with star san.

Just like my previous batch that I put in 100 bottles, this batch, 2-5 gallon corny kegs, had the same nasty phenol/chlorophenol taste as the last few batches. I am stumped... How can this happen after bottling/kegging when everything is clean and sanitized? Could it be something in the C02 tank? Could it be something that is undetectable until the beer is chilled? Please help!! Might have to retire this hobby if I can't find a solution... Thanks, David
 
Chloramine might be be perceived until after fermentation.

Maybe try a batch from another water source? Or add some campden tablets to your water and mix it up right before using.

If nothing else has changed, and experts state their opinion, it's a reasonable place to look.
 
How are you cleaning the kegs? You could have residual chlorine/chloramine from cleaning/sanitizing them if you are using a different water source.
 
How old are your Hoses? My neighbor served me a beer a few weeks ago,and it had a distinctive rubbery/ chlorophenol aroma and flavor. He had just cleaned out his lines with Oxy/Starsan, but we changed out the lines with some new tubing he had anyways, and the flavor was gone. Im not sure how good Oxy/star-san are for beer lines, I've switched to LLC from Five star.

When was the last time you took apart your disconnects too?

To me it sounds like an issue with the kegs, the lines, the faucets or all three.

If you can, hook up a new disconnect with new tubing and a new picnic tap. if its still there, inspect the Kegs and popets.

Sounds super frustration, best of luck.
 
I break down the cornies everytime I fill them. I inspect the inside of the dip tube and run a rifle cleaning pole w/ swab through it to get out any build up. All o-rings are new, the poppets are clean and sanitized, the lines in my kegerator are the new 3/16" accuflex with the glass lining and they are only a few months old. I use star san and don't rinse with city water. I just turn them upside down to drain and when I fill them i always see the foam come out the top. I use the same water for brewing as i do for my sanitizer because the city water makes the star san solution cloudy, and that bothers me.

I can only think of one possible problem, and that would be my sparge water temperature is to hot, maybe in the 180-190 deg range. Could this cause a phenol or other similar effect on the chilled beer that is undetectable at room temperature?

I am quite puzzled my fellow brewers. I appreciate your responses. Any other comments or experieces with this same issue would be very much appreciated! Thanks, David
 
Well, it should be easy to figure out if it is polyphenols that are being extracted from the mash or sparge. Take samples at each stage of the process through kegging, and stick them in the clear plastic cups used for e.g. brewing compeitions, and put them in the fridge covered for a day or two.

Taste each sample and figure out when the flavor kicks in. At the very least, that will help you identify what step to focus on.

If it is caused by infection of some sort, then there will be a bit of a delay between where the problem is introduced, and where you taste it. But from your description, it doesn't sound like an infection.
 
Thanks, but I would be very surprised if it were an infection. I've had to pour out a 5 gallon batch back in the day because I got a little relaxed on my sanitizing methods. Won't do that again, it hurts my heart!

Anyway, when I brew tomorrow I will pay more attention to my sparge water temperatures. Hopefully it's something simple that I stopped doing and have just overlooked. The old saying, "back to basics" maybe very applicable here!
 
You said you sampled it before it went into the keg right? and there was no off flavor,but after being in the keg you noticed it?

If this is the case, It would seem be something to do with the packaging and dispensing, but not necessarily to do with the brewing process.

May be if you can, releas the pressure from the keg and syphon a little beer directly out of the keg and see if the flavor is still there.
 
I had that same flavor over several consecutive batches. I think I narrowed it down to fermentation temperature. What do you use to control fermentation temps? Are you positive it's holding the temperature you expect? I had the fermentation cooler I use overheat once and blow hot air instead of cold... totally ruined that batch with the phenol flavor I had in my trouble batches. I'm not sure if it was just the temps or if my water chemistry had anything to do with it, but once I got a fermentation chamber and started adjusting water chemistry the off-flavors went away.
 
From what I've read, chloramines are pretty hard to filter out. Maybe try another source for water with the next batch and see if that works.

That said, I've never heard of "metallic" are a chlorophenol characteristic. I've always read "medicinal or plastic like a band aid".
 
If you want to eliminate chloramines (or chlorine) from your water, try adding about 16mg per gallon of powdered vitamin C (ascorbic acid) to your strike/sparge water when you start heating it up. This will clean up all the chlorine and chloramine in your water by the time you get ready to dough in/sparge.
 
@hibbleton, I have a nice 15 Cu. Ft. chest freezer that has a Johnson Analog controller regulating my temps. I have it dialed in to hold my temps at about 65 deg. F. I check the glass fermenter twice daily to make sure the temp. strip on the carboy stays under 70 deg. F. Once primary fermentation slows down I adjust the temp a little at a time to keep it around 68 deg.

On another note, i brewed a pale ale this weekend and paid very close attention to my mash temps (152) my ph (5.1) and my sanitation. I also used RO water with an addition of gypsum (9 gr.) and calcium chloride (4.2 gr.) and 1/2 a campden tablet for 10 gallons of water the night before.

It should turn out good but i will continue to be vigilant until the beer is in my belly!
 
About a year ago I had a rash of horrible tasting beer much like what you are describing. It was always an overpowering rubbery, plastic-y aroma and flavor and stayed on your palate for a long time. At first I thought it was US-05 combined with bad fermentation, but it came up in other yeasts. What was also very odd was one batch (an IPA) had the problem, but I used the yeast cake in a subsequent batch (barleywine), and that beer is awesome. Unfortunately, I had to basically trash every "soft" thing (fermentor, hoses, siphon). The flavor has gone away. Sometimes I think I taste it, but its either in my head or I am just hyper-sensitive. I tasted a chai beer a friend brewed and it had the same flavor/aroma, but that was most likely the cloves from the beer.

In the end, all I can pin this down to is a series of unfortunate infections. I got away from tap water for any critical steps, went 100% RO for brewing, careful of my surroundings when racking to the bottling bucket (like close all the windows and make sure you have no breeze!) and meticulous cleaning of carboys after a beer is done.

Hope you solve the problem!
 
Thanks adc123 for the vote of confidence! I too had a few bad batches that were unacceptable to my standards but others said were "ok". I know I am more critical of my beers because I know how good they can potentially be. I am in the process of replacing all my plastic and silicon transfer hoses. When it all comes down to it, the smallest things like basic sanitary practices can make a world of difference. Stay on your game and be relentless in your pursuit of the perfect beer!
 
This is an update to my off flavors perceived to be phenolic in nature:

I have isolated the problem to exactly one specific area in my brewery, the CO2 tank! I have two new batches that have developed this strange metallic flavor about 2-3 weeks into carbonation. I stripped down my entire kegerator, replaced the beer lines, broke down the faucets and cleaned and sanitized it all before reassembling. The beer tasted fine the first week and ok the 2nd but on the 3 week is when this off flavor started to appear. I suspect there is some machine oil or other contamenents in the bottle that is gettting forced into the keg and causing the beer to get this metallic flavor. I am going to install an in line HEPA filter between the CO2 bottle and the keg to see if the next batch has this weird flavor. I will keep you all posted but think about checking your CO2 bottle if you have experienced this same problem. Cheers!
 
I wanted to revist this thread I started some time ago. My previous assumption that my CO2 tank was the culprit of my off flavor was completely wrong! I have since moved my brewing operation from South Texas to Marietta, GA. The water here in Cobb County is great right from the spicket but i am still finding the strange off-flavors that i descibed in my first post. Metallic, after taste, copper penny flavor, etc. Not really phenolic or astringent but slightly medicinal. Anyway...

It hasn't appeared in every batch and I think I know why. I was using filtered water pushed through an inline carbon filter simliar to one made for an RV or external filter for a refridgerator. The active charcoal inside takes care of the cholorine (and our city water supplier uses chlorine not chlorimine to treat). I also added 1 crushed campden tablet to the HLT just incase.

So my first brew was a blonde ale, simple and delicious no off flavors, just a little chill haze which dropped out after a few weeks in the keg. My next batch was an aggresively hopped IPA. Same water treatment as the blonde ale but the only difference was at kegging when i had to make a fresh batch of star san for the IPA.

The new batch of star san was mixed in the recommended amount with straight tap water (unfiltered/untreated) which was not the case with the previous batch used to santize the keg containing the blonde ale. This IPA was wonderful upon sampling at each stage of fermentation all the way into the keg. And then after being on the CO2 for a week it was ruined! That nasty metallic flavor was there like a bad disease.

So I grabbed a growler to take some of the blonde ale to a friend's house and before i did i dunked it into the star san solution used to sanitize the keg containing the IPA. I emptied the liquid, chilled the bottle in the freezer, and then filled it with the blonde ale.

So the next day i took the growler of blonde ale my friend's house who was brewing that day and we tasted it. And I wouldn't believe it if it hadn't happened to me, but with in 24 hrs. the blonde ale had already developed that same metallic flavor that the IPA had. I was embarrased because i had been talking it up as one my best ever! So i chuckled and said "Well, you know homebrew doesn't travel well." lol

So, when i got home that evening I poured myself a glass right off the tap and it was wonderful, no detectable off flavor or metallic twang!

Long story short; DO NOT MIX STAR SAN WITH CHLORINATED TAP WATER AND USE IT TO SANITIZE ANYTHING IN YOUR BREWERY!!!!!!! ESPECIALLY YOUR BOTTLES OR KEGS!!!!! Only mix with distilled or RO water. This will also fix the cloudy solution people have asked about. Store your solution in a keg or glass carboy and use sparingly. I strain mine when i'm done and return it to the container for next time.

I hope that people who have experienced this problem and were as baffled as i was read this post and follow my suggestion. I am in the process of contacting FIVE STAR Chemical Co to discuss the issue with a chemist to see if there is more detailed info to backup my findings. CHEERS!
 
It’s interesting to learn that it only takes a few mL of tapwater to screw up a batch. I’m guessing you’re particularly sensitive to phenol. Do others taste this off flavor?
 
I would say its a very distinctive taste that is not pleasant at all. My palate is pretty good but this off flavor punches your taste buds and lingers on the roof of your mouth as well as the sides of your tongue. I can only describe it like sucking on a brand new copper penny. I call it metallic taste and after taste. Also, another poster on HBT stated that when he burbs the flavor permeates his nose and mouth. I also experienced this and it is very unpleasant. As unlikely as it may seem i am convinced, unless someone proves otherwise, that chlorinated tap water and StarSan is the cause of this off flavor. Which I might add is not listed in any publication or technical beer making guide known to the hobby. You have been warned!! Cheers.


Sent from my iPhone using Home Brew
 
I finally figured out the culprit for this problem. It was simply the soaking of the oxidized copper immersion chiller in the star San solution for too long. I assume most people sanitize their chiller before dropping it in the boil, but I was soaking for hours until the thing looked like a shiny brand new penny. I have recently realized through some research that something called pacification occurs and unwanted metal ions are transferred from the copper to the star San and then to the wort or beer. I'm no chemist but it finally makes since why some beers had this metallic flavor and some didn't. Because sometimes I would use a fresh batch of sanitizer and/or not soak the chiller. I have yet to experience any of the metallic off flavors since selling my immersion chiller and switching to a counter flow. Cheers to all who have had this experience and I hope your home brews are better after you read this.
 
Glad you found the reason! This one makes a huuuuge amount of sense.

For what it's worth, I think many (most?) people, including myself, do not sanitize their immersion chillers before putting them into the boiling wort. The boiling does it for you! I typically put mine in with about 10 minutes left on the boil, although I don't think an entire 10 minutes is necessary.
 
I finally figured out the culprit for this problem. It was simply the soaking of the oxidized copper immersion chiller in the star San solution for too long. I assume most people sanitize their chiller before dropping it in the boil, but I was soaking for hours until the thing looked like a shiny brand new penny. I have recently realized through some research that something called pacification occurs and unwanted metal ions are transferred from the copper to the star San and then to the wort or beer. I'm no chemist but it finally makes since why some beers had this metallic flavor and some didn't. Because sometimes I would use a fresh batch of sanitizer and/or not soak the chiller. I have yet to experience any of the metallic off flavors since selling my immersion chiller and switching to a counter flow. Cheers to all who have had this experience and I hope your home brews are better after you read this.

Glad you found your problem. :ban:

You didn't need to get rid of the IC to cure this problem, however. Most IC users just put the coil in the boiling wort with 10 - 15 minutes left to go in the boil. No need to place it in StarSan or any other sanitizer.

An acid sanitizer (like StarSan) removes the protective oxide layer from the copper coil. That's why it gets nice and shiny. The removed oxide ends up as copper ions in the sanitizer solution. Cu ions can then get into the wort from the "contaminated" sanitizer. Another possible source of Cu in the wort is from the coil itself which no longer has the oxide layer, so some Cu may get dissolved in the wort from the coil itself. Not sure which of these potential paths for Cu into the wort is the more important.

Brew on :mug:
 
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