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Off flavor recovery from failed bung?

I had a rubber bung and thermowell fall into a batch of American Wheat. I fished out the temp. sensor but left the bung and thermowell in the carboy threw and airlock on, taped and insulated the temp. sensor to the side of the carboy and took the RDWHAHB approach. Unfortunately that seems to have been a mistake since the beer now tastes like the rubber bung. I noticed the off flavor before I transferred to the keg, but hoped that through carbonation the funky taste would be forced off but I was wrong.

To pre-answer some of the followups… all equipment including bung and thermowell were sanitized with Starsan solution, keg and lines were also freshly cleaned and sanitized. Pretty confident the flavor is from the bung and not some other issue that occurred during fermentation or transfer.

Has anyone had this happen before and were you able to save a batch from the off flavor?
I was thinking about adding some fruit to the keg or maybe some sort of dryhop but I’m not sure what direction to take here.

Any advise would be greatly appreciated to try to save the batch for a party next weekend.


That’s strange

I don’t think an off flavor would come from the bung being in the beer. If the bung was designed for brewing it would not be made of materials that would leach chemicals into food, or beer.

How long was the beer in the fermenter? Rubber/plastic/bandaid taste could be oxidation.

Could also be some kind of infection. If the bung was on for a while before it fell in it could have brought something from outside the fermenter with it. A wild yeast or bacteria?

I don’t think bungs are made to be in contact with wort or beer. They’re just an air tight seal.

The solid and drilled stoppers are gum rubber. So I think it’s possible they could impart a flavor.

The hollowed out bungs that NB sells (which look like the ones I get at my LHBS) just say plastic. No other description of materials. No mention of food grade or anything.

You can buy silicone bungs and stoppers but they cost a little more and I wouldn’t expect any flavor transfer from them.

Edited to add:

If it’s one of those orange caps I’ve seen used for thermowells I would have gotten that crap out of there as quickly as possible. That has a made in china plastic look about it to me.

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Maybe not so strange. I’m only familiar with the ones I get from my home brew store. Seem pretty innert to me

It wasn’t your typical drilled stopper, it was sorta clear and not like the ones I had used before. It came with the thermowell. I just sanitized and popped it into the carboy. Fermentation took about a week and was in a ferm chamber so the temp was set at 64 the entire time. I guess it’s possible that some contaminants fell in along with the bung.

Anyone know if there is a way to save it, still looking for ideas since the damage is already done.

If it doesn’t smell bad use it to wash your hair. If not dump it and try again. Life’s to short to drink crspoy beer

Sounds like silicone.

So ifn it may be silicone, you wouldn’t git a off flavor, I think DB has it, that there is an infection lurking in the shadows. It will get more pronounced as time goes on. Try another sample ASAP, if you have some camp den tablets, crush a small bit and mix with the left overs to kill any bug living in it. Cover and put it in the fridge. And in a couple of days, pull another sample and do a side by side comparison. You are trying to confirm its growing, or just dump it… Sneezles61

a leaking bowel

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