Persistant off-flavors from a corny

[sarsnik]

I've had three batches that I put into one of my cornys that ended up developing off flavors a couple weeks after pressurizing.

They've developed a distinctive medicinal or phenolic taste and smell - not subtle at all. The keg, when empty, also smells similar. It took about a week and a half after kegging it for the taste to become noticeable. This was post fermentation, so I torn between whether it's an infection or if it's residual soda flavors leeching from the keg (I don't know why stainless would retain flavors, let alone smells)

Things I've tried:
After first batch went bad, I assumed I just didn't sanitize properly. Disasembled everything, sanitized, then kegged another batch.

After the second went bad, I thought maybe it was residual flavors leeching from the keg, so I filled the keg with b-brite for about 24 hours, inverting it a few times.

After this third batch failed, I'm at a loss of what might be causing it. Any help would be greatly appreciated - I don't want to have to trash this keg it if continues to fail.

 

[foodplusbeer]

I don't know if it's possible, but I've always wondered if you can fill a corny part way with some water, and lay it sideways over a gas burner to heat the side. If it's possible my guess would be that the boiling water and steam will kill whatever you've got in there. Anyone know if this can be done?

 

[sarsnik]

I was contemplating trying that, but the rubber would certainly burn. Better off just dumping in boiling water.

I was also considering running caustic through all the stainless parts.

I am also fairly certain that this isn't caused by my system - I've brewed three other successful batches that were fine in my other 2 kegs.

 

[foodplusbeer]

you could pull off the rubber gaskets, and just put a little but of water in it. Again, not sure, but as long as you dont have direct heat on the rubber parts, I dont think that the heat from the steam inside would cause any trouble to them.

 

[CidahMastah]

Why are we boiling in the keg again? How about just PBW with 160 water? Lid off and guts tossed into the keg.

Have you tried one step?

I have found that of you do a PBW soak overnight, replace all the seals the keg will be pretty clean but may have some off smells in it. One step however does a great job of removing off smells and flavors from kegs etc. Starsan doesn't do that.

use hot water from your tap and make up the one step. Soak in the keg until the off flavor disappears. Usually a few hours is fine, but 24hrs should do it. You might as well daisy chain your kegs up and swap from one to the next and get them all done over a week or so.

YMMV

 

[mjohnson]

I'd probably replace all the o-rings to eliminate that vector. Another thing - do you use the same disconnects/lines on the same keg each time? If so, maybe you're cleaning the keg just fine, but the hookups are the problem.

Just trying to think outside the box.

 

[pfgonzo]

I agree, double check your lines. Swap to a diff set if you have them.

As for the corny, strip it down, place the guts in a small bucket/bowl of hot oxi/pbw and let it set. Fill the corny to the top with the same for a few hours, and then quickly upend it into a bucket. Let it set upside down for a few more hours to get the top. That should clean it pretty thoroughly.

New gaskets, and star san the thing and you should be golden. If you're still getting off flavors, it might be your brew/ferment system, and not the keg.

 

[sarsnik]

I did all that cleaning with b-brite, but the consensus is that I should try PBW instead? Or possibly one step? Would scrubbing the inside with BKF and/or sodium bicarbonate aid in removing residual smells, or is it possible they're trapped under the surface?

Concerning the lines and disconnects - I know that the lines have differed from each batch. The keg actually has been in two different kegerators. I can't be sure I've used different disconnects. What sorts of infections can I get post-fermentation, out of curiosity?

 

[Gduck]

Those rubber gaskets can absorb some flavors and harbor all sorts of stuff. They can be hard to effectively sanitize once they've soaked up something nas (and if they leech some flavor, like soda, they never give that up). O-rings are cheap, get a new set for the keg. All the cleaning you've already done to that keg has essentially eliminated the inside stanless and dip tubes as culprits.

 

[Golddiggie]

Are you cleaning/sanitizing with chlorine based products/solutions? What are you using for water?

 

[CidahMastah]

I did all that cleaning with b-brite, but the consensus is that I should try PBW instead? Or possibly one step?

I have never used b-brite. But my inkling would be that if the keg is clean, try using one step. If that stuff wasn't so much more $ than what I can buy star san for I would use it all the time. I dont like the foaming of starsan, and it doesn't absorb odors like I have noticed with one step.

When I switched to starsan I noticed my kegs retained the smell of the preceeding beer than when I used one step.

 

[luhrks]

starsan is a Sanitizer, not a cleaner.

You clean with PBW etc first and then use starsan to sanitize the keg before you use it.

 

[CidahMastah]

starsan is a Sanitizer, not a cleaner.

You clean with PBW etc first and then use starsan to sanitize the keg before you use it.

I am well aware (see post 5)

 

[luhrks]

Read the entire thread before replying? Perish the thought.