The dreaded chlorophenols...

[brewhaha]

So it's finally happened. I have a batch of Nut Brown ready for bottling but the gravity samples I've pulled have a medicinal/plastic taint to them.

My tap water is heavily chlorinated (as well as having very high bicarbonate levels) & so I predominantly use Tesco Ashbeck for the entire liquor volume. However, for some of my darker brews, I do use some tap water to help offset the drop in mash pH from darker grains. Normally I use Campden tablets to dechlorinate this but I completely forgot for this batch. Doh!

I now recognise this off flavour in 3 previous batches; a porter, California common & mild (all with a good chunk of dark grain so all used some tap water to some extent) but my notes say I used Campden tablets in all of these to dechlorinate.

Also, I have a previous batch of nut brown & 2 batches of red IPA that had a portion of Campden treated tap water & they came out fine.

So my questions are (sorry for the rambling!), why only the off flavour in some batches that use Campden treated tap water? What's everyone's protocol for using Campden to dechlorinate (i.e. mass used, time left to work, covered/uncovered etc.)? Is Campden just a bit hit & miss for this use?

 

[peebee]

I've recently had the "sticky plaster" medicinal taste. But I brew two kegs at a time - one keg had the taint, the other didn't. So in my case I had proof that the issue was caused by the keg, not the water or brewing gear.

So I'm beginning to suspect over-soaking, and subsequent inadequate rinsing, of plastic items in chlorine based cleaners/sanitisers like VWP (the SS kegs have a length of silicone hose inside them). Bleach as a brewery cleaner is becoming popular now and that needs a lot of rinsing to prevent it tainting the beer (it was once considered impossible to rinse off effectively).

 

[foxbat]

Another Ashbeck user here. For my darkest brews, eg. My RIS I use 100% Morrisons Yorkshire Vale instead to get the required mash alkalinity.

My approach to removing Chlorine is to not have it there in the first place. @peebee VWP on porous silicone? Did you really do that? aunsure....

 

[BeerCat]

I have had the same as @peebee recently. The keg tasted of bandaid yet the bottles were fine. Annoying to throw it away because of hygene.

 

[peebee]

... @peebee VWP on porous silicone? Did you really do that? aunsure....

Okay, I'll stop it! The porosity of silicone has caught me out before on something quite unrelated (oxygen) so I don't need much convincing that silicone is the demon.

 

[Sadfield]

I wouldn't rule out Wild Yeast as the source of plastic (Styrene), medicinal (4-ethyl phenol) or clove (4-Vinyl guaiacol) flavours. All can be easily confused with Chlorophenol (2,6-dichlorophenol) flavours from untreated water or cleaning agents.

 

[brewhaha]

I've recently had the "sticky plaster" medicinal taste. But I brew two kegs at a time - one keg had the taint, the other didn't. So in my case I had proof that the issue was caused by the keg, not the water or brewing gear.

So I'm beginning to suspect over-soaking, and subsequent inadequate rinsing, of plastic items in chlorine based cleaners/sanitisers like VWP (the SS kegs have a length of silicone hose inside them). Bleach as a brewery cleaner is becoming popular now and that needs a lot of rinsing to prevent it tainting the beer (it was once considered impossible to rinse off effectively).

I steer clear of VWP & the like now for that very reason. Rinsing off a chlorine based cleaner with chlorine heavy water seemed futile!

Another Ashbeck user here. For my darkest brews, eg. My RIS I use 100% Morrisons Yorkshire Vale instead to get the required mash alkalinity.

My approach to removing Chlorine is to not have it there in the first place. @peebee VWP on porous silicone? Did you really do that? aunsure....

That's a really good idea. Co-op's own brand water is fairly heavy on bicarbonate as well & that's round the corner. Will try that for my upcoming stout.

I wouldn't rule out Wild Yeast as the source of plastic (Styrene), medicinal (4-ethyl phenol) or clove (4-Vinyl guaiacol) flavours. All can be easily confused with Chlorophenol (2,6-dichlorophenol) flavours from untreated water or cleaning agents.

The flavour is pretty consistent across all 4 problem batches. Would flavours from wild yeast not vary more dramatically, even if it's producing the same phenols?