Chlorophenol issue.

[robcj]

I’ve been brewing for nine years. I’ve brewed four beers this year and two of them have exhibited a distinct medicinal or Aspirin-like aftertaste that I associate with chlorophenols. I'm confident that it isn't excessive hop bitterness or astrigency--I unfortunately know those characteristics well enough from brewing experience.

I also know the typical cause of chlorophenols is chlorine or chloramine in brewing water. I treat my tap water with Campden. I still remember the taste of chlorophenols due to the chloramine in my tap water from my early days of brewing, before I treated my water. That taste was very much like plastic or Bandaids. This new taste is different but still in the same family.

Here's what was common between the four batches:

- Also treated water with CaCL and acid malt.
- Brewed on a Grainfather with the same process.
- Fermented at the same temperature of 19C (66F).
- Transferred under pressure to kegs that were previously filled with Starsan and purged.
- Fined with gelatin and burst carbonated.
- Turned around in 2 weeks.

Here’s what was different:

- The two without the aftertaste were Pilsner and Hallertau Mittelfruh SMaSH lagers fermented with 34/70.
- One with the aftertaste was a 2-Row, Vienna, Crystal 15 and Citra / Amarillo pale fermented with US-05.
- The other with the aftertaste was a 2-Row, Wheat and Lemondrop / Idaho 7 wheat fermented with Wyeast 1272.
- The two with the aftertaste were fermented in the same fermenter.
- One of the lagers was fermented in that same fermenter but before the pale and wheat.
- I don’t know which fermenter I used for the first lager which was brewed before the other beers.

Here’s where I’m at:

- I don’t think it’s my brewing water because I treat it and perceive this flaw to be different than the flaw expressed by untreated water. Also, two of my recent beers using the same water did not exhibit the flaw.
- I don’t think it is a due to recipe or ingredients though I acknowledge that the beers with flaws both featured 2-Row, more expressive hops and ale yeast. I also know that different beers can mask different flaws but I doubt that my clean and simple SMaSH lagers are burying a taste that my more complex and hoppy ales can’t hide.
- I don’t think it is fermentation temperature. I control my temperature and these beers were all fermented at the same temperature.
- I think an infection of some sort is possible, likely centred on that specific fermenter or maybe my pressure transfer equipment.
- I also wonder if my use of untreated tap water to make my StarSan solution could be contributing chlorophenols? I use the solution liberally throughout all parts of the brewing process. Should I use Campden on my water for StarSan?
- Does anyone else have any ideas?

I have another lager in the other fermenter right now. I wish I had used the same one as that would have been a good if unintentional test.

 

[Yooper]

I went through something similar a while back. I had 10 gallons of band-aid beer, and couldn't figure it out. I eventually traced it back to a contaminated yeast starter.

In your case, though, it sounds like different (fresh) yeast strains. Still, if it's not chlorine that's the only thing I can think of- a low contamination creating infection somewhere.

The fermenter was what they had in common?

 

[robcj]

Thanks for your reply, Yooper. You are right—they used the same fermenter. I have another SMaSH lager in the other fermenter right now. If it doesn't exhibit the aftertaste—I'll know within a week—then it will be further evidence that it is a low-level contamination with the specific fermenter. (Though it won't eliminate the possibility that it is recipe-related.)

Regardless, I'm going to go on a bit of an extra-aggressive cleaning and sanitization blitz this weekend across everything—Grainfather, fermenters, fermenting chamber, kegs, tubing, etc.

I'm also going to switch to RO water for my StarSan. Like many brewers, I use it a lot—including after I clean my Grainfather and when I purge kegs before filling them. This will at least negate the possibility of chloramine contamination due to StarSan, however small that may be. It will also increase the longevity of my StarSan solution, I think.

 

[IslandLizard]

I doubt the chlorine/chloramines from the non-dechlorinated water used in your Starsan cause flavor/aroma problems, as the carry-over is (or should be) minimal.

I do dechlorinate all my tap water used in brewing (and soup), including used in the bucket of Starsan, with a pinch of K-meta, while filling the vessel. My tap water is fairly soft, so using RO water won't make much difference here. It does turn cloudy though, within hours or a day.
Still use it fine for weeks, months even.

Your problem indeed seems to point to contamination somewhere. It's very possibly in repitched yeast, although that wouldn't account for the off flavor in your US-05 batch if that was pitched from dry (and fresh).
Could well be a biofilm in your fermenter, transfer tubing, etc. What are your fermenters? How do you clean them?

 

[robcj]

Thanks for your input, IslandLizard. I agree that the water used for my StarSan solution is unlikely to be the problem but I went ahead and bought some RO water, primarily for the StarSan I transfer between kegs when purging them.

I sampled my latest beer, a NZ Pilsner (Pilsner, Vienna, Wheat with Motueka hops and 34/70 yeast) while pressure transferring it to a keg and it didn't exhibit the phenolic aftertaste (in fact it was amazing--Motueka is really interesting). So it's either a contamination, likely in a fermenter, or something gone wrong with specifically with my ale recipes, but I doubt the latter given the variety of ingredients I've used.

I don't harvest or reuse yeast—it's always new.

I spent most of the day yesterday deep cleaning everything (and I mean everything from brew day equipment to serving equipment—even my gas lines) and I noticed one of my fermenter lids had a sour smell even though it looked visually clean. So the answer to your question about how I clean my fermenters may just be "not well enough."

If the NZ Pilsner continues to taste great as it carbonates over the next couple of days, I'll be happy. I'm planning to brew a pale ale this weekend—that will be the true test.

 

[robcj]

I’m following up to report that the NZ Pilsner stayed true—no chlorophenol flavours.

Even better, I did brew an ale as promised two weeks ago—specifically a Mosaic NEPA—and I’m very pleased to say that it looks like it might be my best beer yet. None of the off flavours I experienced with the two other recent ales.

I feel confident attributing my earlier issue to a tricky infection of some kind that I eliminated with some aggressive cleaning and sanitation. Although I would suggest that the vast majority of chlorophenol issues experienced by newer brewers will be the result of failing to address the local chlorine- or chloramine-based treatment of their source water, I think infection is a cause worth considering when chlorophenols are affecting a more experienced brewer.

I’m really happy because this is turning out to be a banner year for brewing for me. I fixed an oxidation issue I was having by implementing closed transfers and transitioning to cold crashing in kegs instead of fermenters—and now I believe I've addressed this issue too.