Keg woes: TCP taste

[Sandimas]

I've posted before on this, but now have a stainless-steel minikeg in addition to 3 plastic kegs which has further perpelexed me!

• My plastic-kegged beer develops a TCP-taste after a few weeks in the keg. In all 3 kegs, 2 budget bottom-tap kegs and a top-tap Rotokeg.
• It's not the beer: I often half-bottle batches, and the bottled versions are always fine, even 4 months after bottling. The kegged beer is like nail varnish by then.
• The plastic kegs are carbing up fine, I usually only add a bit of priming sugar and use an external CO2 bottle to pressurise.
• I recently acquired a stainless-steel 10L minikeg, the beer in there is not developing the TCP taste.
• To try to eliminate the problem, I bleached the bejesus out of one of the plastic kegs before Christmas, rinsed well multiple times, and filled it 3 weeks ago.
• I also added CO2 via the top-cap straight away, and released a little, to try to purge the keg of oxygen.
• And guess what: the beer that was initially fine 3 weeks ago is starting to develop the TCP taste.

I can't think of anything else to try. The plastic kegs never used to do this, but started doing it after 3-4 years of use.

Any thoughts before I send 3 kegs to the recycling centre?

 

[Buffers brewery]

Camden tablets?

 

[An Ankoù]

In my experience, TCP taste comes from either chlorine interacting with hops in the boil, or a wild yeast infection. The first happens immediately and the second develops over time, but is usually discernible towards the end of fermentation. As you've bleached the holy beggorah out of your PV it should have killed everything within twenty yards. If you hadn't washed the bleach away properly, it would just taste of chlorine (swimming baths) rather than TCP. I'm at a loss. I think the wild yeast infection is getting in there somehow. Don't send the kegs to recycling. I'm sure we can pin this one.

Do you a convenient and safe gamma source?

 

[soupdragon]

The only time I've had that TCP taste was when using the metal mini kegs. I used to use the "no rinse" chemipro oxi stuff. Once I started rinsing it out the taste disappeared. The kegs I used to have were a pain to drain properly due to the lip in the centre of the keg.
All I can suggest is to keep rinsing after using the bleach?

Cheers. Tom

 

[ppsmith]

I've had TCP flavour once in a batch of beer that I bottled. Local wisdom at the homebrew club was that the chlorine based cleaner I had used hadn't been rinsed properly and the chlorine had reacted with hop phenols to produce TCP - hence that specific flavour. Tasted like a beer that had had a shot of Laphroaig thrown into it.

If you're using a chlorine based sanitiser (bleach, VWP etc) maybe swap out for Starsan or some other non-rinse sanitizer?

 

[The Baron]

just a thought dismantle the taps and rinse really well as any infection/contamination can usually be found in the taps sometimes

 

[strange-steve]

It's going to be one of these:
1. Wild yeast contamination
2. Bleach not rinsed well enough
3. Chlorine in the water

 

[Sadfield]

As mentioned, strip down all the taps seals etc. If you're cleaning regime is identical between bottles and kegs, then it'll be the kegs themselves that are the issue.

How long are plastic pressure barrels expected to last for? Expanding and contacting most plastics will degrade them.

I struggle to see how a chemical contamination would build over time, which points to brettanomyce contamination that's taken residency. I'd question how it got into three separate kegs, and also be looking at your fv and general cleaning routine.

 

[Dads_Ale]

just a thought dismantle the taps and rinse really well as any infection/contamination can usually be found in the taps sometimes

I will second that. If you have the taps where the body rotates over time the beer can get between the seals. This doesn't get removed during cleaning and will become a source of infection. My mate had to ruined batches from this.
They can be difficult to get apart but it is worth the effort. Before reassembly I find a thin smear of food grade silicone grease on the seals prevent the ingress in the future although I would still take apart every few brews just to double check.

 

[foxy]

I've posted before on this, but now have a stainless-steel minikeg in addition to 3 plastic kegs which has further perpelexed me!

• My plastic-kegged beer develops a TCP-taste after a few weeks in the keg. In all 3 kegs, 2 budget bottom-tap kegs and a top-tap Rotokeg.
• It's not the beer: I often half-bottle batches, and the bottled versions are always fine, even 4 months after bottling. The kegged beer is like nail varnish by then.
• The plastic kegs are carbing up fine, I usually only add a bit of priming sugar and use an external CO2 bottle to pressurise.
• I recently acquired a stainless-steel 10L minikeg, the beer in there is not developing the TCP taste.
• To try to eliminate the problem, I bleached the bejesus out of one of the plastic kegs before Christmas, rinsed well multiple times, and filled it 3 weeks ago.
• I also added CO2 via the top-cap straight away, and released a little, to try to purge the keg of oxygen.
• And guess what: the beer that was initially fine 3 weeks ago is starting to develop the TCP taste.

I can't think of anything else to try. The plastic kegs never used to do this, but started doing it after 3-4 years of use.

Any thoughts before I send 3 kegs to the recycling centre?

Something which we all may come across, happened to me recently, it was something I did which at the time I knew that I shouldn't have done it. Bottled, could smell band aid, should have followed my first train of thought and abandon. Didn't, and regret it, tried to recall what it was I did to set alarm bells ringing. Ended up tipping the lot and cleaning the bottles, I really do think it was brettanomyce.
Hope this helps.
https://londonamateurbrewers.co.uk/wp-content/uploads/2015/05/Complete_Beer_Fault_Guide.pdf

 

[Sandimas]

I should have added, this has plagued me for the last few years and I haven't touched the kegs in 18 months. I thought I'd give it one last go. So I gave them a real deep clean, stripped down the tap, bleached everything: it's spotless.

To those who mention water, chlorine, Camden tablets etc why is this just happening with the kegged beer? As I said, I half-bottle some batches and they are absolutely fine, it's the same beer from the same batch that goes off after a few weeks in the kegs.

That's the bit that's perplexing: it seems to be my method/equipment rather than the beer. And it's happening with 3 separate plastic kegs (old), but not the new stainless steel minikeg,

Brettanomyce does sound like a possibility, and I had a real bad infection across all my kit about 5 years ago that I managed to clear up. Still can't explain why it isn't in the bottles though?

 

[Drunkula]

My tcp/band aid problem came from chlorophenols cause by chlorine and bleach. If you're bleaching your plastic barrel then it's going to leach into the plastic. You could try doing a soak with campdened water to neutralise it.

In the pdf that Foxy links to there's a section on chlorophenols and it says tasting it is genetic which I never knew and some people are completely unable to taste it which would hint towards why some people say they never have a problem using bleach.

I did a test where I dipped my finger in thin bleach and licked my finger and it didn't taste like tcp, then when I swilled my mouth out with my tap water the taste immediately smashed your around the chops - it was crazy strong and lasted for ages. My tap water stinks of chlorine when you pour a glass and first get it up to your beak.

So I'd fill the barrel, wakk in a campden tablet or two and leave it to soak and of course campden your water for brewing.

 

[Sandimas]

So I'd fill the barrel, wakk in a campden tablet or two and leave it to soak and of course campden your water for brewing.

This has got me thinking. I don't use Camden tablets as I have a 3rd tap on the sink with an inline water filter (recently renewed) that removes Chlorine etc. I use this for all my brewing. However, because of the filter, the flow rate is quite weak, so I tend to use water from the main tap to rinse the barrel. I wonder if it's this, I'll try a Camden tablet in there next time.

 

[kelper]

@darellm How much chlorine would you use to clean a barrel?

 

[JockyBrewer]

As others have said, as it develops over time the most likely thing is a wild yeast infection.

Take the taps off, split them apart and clean/bleach them.

While I know your bottles and the stainless keg seems to be ok, I’d also consider looking upstream and doing the same for any hoses, siphons, and taps - take them apart to the smallest part and clean/bleach. Ball valves in particular need splitting apart.

Good luck.

 

[JockyBrewer]

Also I highly recommend this stuff as an alternative to bleach: Five Star Io Star 16oz

 

[Bill_g]

I had a problem with my first fermenter which was plastic. I found that it had some deep scratches on the inside I assume from the way the beer kit was packed with items inside the fermenter. I replaced it with a stainless steel fermenter & touch wood have had no TCP flavours since. Plastic is generally unavoidable in the overall process but I now prefer it not to be in contact with the beer for long durations. I wonder if the pressure barrels have some defect which has become infected? A narrow crack or scratch would be very hard to properly sanitise and perhaps could be a hiding place for a yeast or bacteria.
I'm afraid I have little patience for dubious kit and just bin it. To me it's not worth the waste of huge amounts of time and brewing ingredients.

 

[Sandimas]

I'm afraid I have little patience for dubious kit and just bin it. To me it's not worth the waste of huge amounts of time and brewing ingredients.

I'm reaching that point very rapidly: this was a last-ditch effort after a real deep clean including tap strip-down, but the TCP taste is getting worse day by day. I may just leave it to see if there's any visible sign of infection after a week or so. I'm also going to try a bottle from the same batch of beer tonight just to check it's not the beer: every time I've done this in the past it's only been the kegged part of the batch that has gone off.

 

[kelper]

I'm reaching that point very rapidly: this was a last-ditch effort after a real deep clean including tap strip-down, but the TCP taste is getting worse day by day. I may just leave it to see if there's any visible sign of infection after a week or so. I'm also going to try a bottle from the same batch of beer tonight just to check it's not the beer: every time I've done this in the past it's only been the kegged part of the batch that has gone off.

How much chlorine did you use?

 

[Sandimas]

How much chlorine did you use?

Sorry, saw your post before but it confused me: I didn't use any Chrlorine, I was talking about Chlorine in the tap water.