Keg woes

[Sandimas]

I have 2 kegs, a budget and a King Keg, that keep getting infected. The beer that goes in is fine, and it's great for a week or two, then it looses any hoppiness and gets that horrible nail varnish / TCP taste. I know it's the kegs doing this as I half-bottle each batch and they're fine. Kegs are well cleaned and sanitised.

Frustrated by this, I borrowed my brother-in-laws budget keg which is virtually unused, and put a beer in that a few weeks ago. It was one of the best beers I've made with a subtle hoppiness, we were having a few pints a night over half term week, then back to work this week. Tried one last night and it had completely changed and the TCP taste is there. Can't believe that this one is infected too.

What am I doing wrong? I have no problem bottling, in fact some of my stronger bottled beers are over a year old.

Anyone else experienced this? Kegs were fine when I first started using them a few years ago.

 

[Honk]

What are you using to clean and sanitize the kegs? Anything chlorine based could give a TCP taste if not thoroughly rinsed away.

 

[braziliain]

Really sorry to hear this as changing to kegs has encouraged me to brew more.

Doing a bit of reading around it seems that acetone taste is most usually associated with high fermentation temps (this can't be the problem if it tastes fine in the bottles) but that it can also come from introduction of oxygen after fermentation.

Are you careful not to pick up O2 in transferring from FV to keg? Are you purging keg head space with CO2?

 

[Sandimas]

What are you using to clean and sanitize the kegs? Anything chlorine based could give a TCP taste if not thoroughly rinsed away.

VWP. But wouldn't it be there initially, and in the bottles too? Beer taste is fine for a few weeks then starts to get progressively worse.

 

[foxbat]

VWP. But wouldn't it be there initially, and in the bottles too? Beer taste is fine for a few weeks then starts to get progressively worse.

VWP is your culprit. It's a superb steriliser because it releases chlorine but that same chlorine is being converted to chlorophenols by the small amount of yeast that's still in the beer. I still use VWP on glassware because it's so easily rinsed off but I'd never use it on plastic (porous and relatively rough surface) because it killed one batch of beer for me years ago and that was enough. All that work down the drain. Never again. PBW or supermarket Oxyclean for cleaning and a good Starsan final rinse is all you need.

 

[Dads_Ale]

I’m with foxbat on this one.
I also found VWP does not get rid of the brown build up. I used VWP for ages to clean my boiler and it got browner and browner. One good dose of PBW and it came up like new.

 

[braziliain]

+1 for fragrance free Oxyclean and rinsing with water before sterilising with starsan.

 

[connor7932]

if your bottling half the brew,then kegging,do you have a lot of head space in the keg.
are you purging the O. out with CO2..

 

[peebee]

I do not consider VWP is all bad. But it certainly doesn't pay to ignore the instructions.

Trouble is, convinced you have an "infection" the instructions go out the window. I guarantee you dose too high and leave in contact too long which has the exact opposite effect to what you are trying to achieve. Mix according to the instructions. Don't leave in contact for longer than the suggested 15 minutes. Down the drain with it soon after mixing - after a couple of hours it is losing effectiveness (and has cooled right down anyway). VWP doesn't need many hours to turn stainless steel black either.

Like other here I'm moving away from VWP for anything containing rubber or plastic (including silicone rubber) and instead using sodium percarbonate and finishing with Starsan.

 

[Sandimas]

Maybe all is not lost then - I'll try Starsan and report back.

And no I'm not purging the O, not sure how to do that?

Thanks for all the help.

 

[Hoppyland]

And no I'm not purging the O, not sure how to do that?

For me, this could well be the problem. If the beer in your keg starts out with a headspace that is basically air then you have two problems. First, the air contains oxygen, so you will very definitely get a gradual deterioration in the quality of your beer due to the chemical effect of oxidation. But also, the air will contain biological contaminants - and some of these will thrive in an environment that contains oxygen, and will gradually produce off-flavours in the beer - including "medicinal" or "chemical" type off-flavours.
Presumably, you dispense the beer from your kegs using CO2 under pressure. Purging simply means to introduce CO2 into the headspace above your beer before you pressurise the keg, so that the inflow of CO2 flushes out the air. You could experiment to see if this is the problem when you next bottle some beer. Try filling 1 bottle only half-full, and maybe a second bottle 1/3 full, so that there is a fair amount of oxygen in the headspace. Cap them, so they are sealed, and leave for several weeks. See what the beer is like, compared to your usual full bottles.
If this is the problem, then your kegs have indeed had an infection. In which case you will have to totally dismantle them - down to every joint and seal. Thoroughly clean each component and sterilise (not sanitise!!) them.

 

[Sandimas]

Presumably, you dispense the beer from your kegs using CO2 under pressure. Purging simply means to introduce CO2 into the headspace above your beer before you pressurise the keg, so that the inflow of CO2 flushes out the air.

I haven't been priming my beer in the keg recently, just giving is a good dose of CO2 from a Hambleton-Bard cylinder to pressurise - is this the same as purging? Sorry not quite understanding what you mean by purging and how to do it with a keg with an S30 cap.

 

[Hoppyland]

Just pulled this from an American forum. It's the sort of infection I used to get years ago before I fully purged every time I transferred. I used to get this flaky, white floating crust, and a horrible taste (pear-drop, amylactetate). If your keg beer begins to taste really antiseptic/chemical after a couple of weeks then I suggest you take the top of without disturbing it too much, shine a torch in & see if there's any dubious-looking growth on the top of your beer.

 

[Hoppyland]

I haven't been priming my beer in the keg recently, just giving is a good dose of CO2 from a Hambleton-Bard cylinder to pressurise - is this the same as purging?

Oops - sorry, I just assumed that you meant a Cornelius-type keg, not a plastic pressure barrel. My fault entirely! Didn't read your post properly. No, purging is not the same as pressurising. When purging, you introduce CO2 into the keg, but at the same time allow it to vent and not build up pressure. So, the CO2 entering the keg displaces the air. I use a 6kg welding cylinder of CO2 so I can afford to use quite a lot of gas to flush all the air out.The principle is the same with a pressure barrel - but if all you have is HB cylinders then it would not be economic to use these to purge your headspace if it is large. A long, long time since I used a pressure barrel - but that's when I used to get problems. My suggestion would be to fill the barrel as full as possible, so that only a wee twist of the cylinder will introduce enough CO2 to flush much of the air out - with the pressure cap fitted only loosely so that the purged air can escape past the threads. I guess a little priming might be good as well - so you can periodically release the pressure, which will itself reduce the oxygen content in the gas above your beer.

 

[connor7932]

yes, i think you got one O of a problem.keg all the brew,or bottle it all.oxygen is life,
the space your leaving is like tapping a cask,and a week later it has a growth inside it.
better if you have cornys ,and pub gas bottle.pushing air out when injecting CO2.
pressure barrel,invest in a 10 liter one,xmas is coming.stock up!

 

[terrym]

First using a nearly new PB should discount any long term contamination lurking on the inside of the PBs. So if its a TCP taste surely that's chlorine related. And the only sources of chlorine are the original brewing water and VWP. But if the bottles are OK then you should be able to discount the brewing water which leaves VWP. So try something non chlorine based to sanitise as your first step and see how it goes.
That said I use VWP to sanitise and leave it in my PBs for some time (and neither do I purge out oxygen from the PBs after filling) and never suffer from TCP taste.

 

[Hoppyland]

First using a nearly new PB should discount any long term contamination lurking on the inside of the PBs. So if its a TCP taste surely that's chlorine related

Yep, that makes sense. Except..... We have such inexact communication on an internet forum. What exactly is a "TCP taste". Personally, I'm not sure - although I've certainly never tasted TCP, only smelled it. For me, anyone following the instructions on the bottle and using it as a mouthwash/gargle needs certifying (well, assuming thay survive the experience!!)
I've had some poor beers over the last 50 years, and some odd flavours/aromas. I've never experienced beer that smelled or tasted like TCP. Medicinal, possibly. Strange organic-chemical, yep. But TCP? Never, not even remotely similar, so I don't know how to interpret what the contaminant is.
The Candida/Mycoderma infection that I was suggesting produces a strange smell - unfamiliar to anyone who has never smelled amyl acetate - therefore possibly unclassifiable to them (pear drops/nail polish remover might be analogues). On the other hand, I use loads of neat bleach as my main sterilising agent, and I've never thought it caused any problem with an off-flavour.
Yes, using a nearly-new PB should discount any long-term contamination problem - unless the problem is an aerobic organism that has been inadvertently transferred and has thrived because there is oxygen in the headspace of the new PB.
So, for me, the problem is unlikely to be an infection (but possibly so), and unlikely to be chlorine caused (but possibly so), but appears persistent. Then all that can be suggested is to go back to basics. Sterilise all the kit, and try to avoid chlorine contamination in future.