Kegged beer went off ?

[Chuckie]

Hi Guys,
I've only been kegging for a while, but have just had an odd case of beer going off in the keg.
I brewed an IPA and popped it in the keg 5 days ago.Force carbonated for 2 days.
On the 3rd day it tasted great. On the 4th day it was still great.
On the 5th day it tastes and smells like rubbish.
The beer has lost all it's bitterness, it now tastes "sweet" and has almost no flavour.
And it smells, best as I can describe, like B.O. (body odour!).
It was a keg I hadn't yet used but I did give it a full sanitise.
The only thing I can think of is that this is the first time I have had all 4 kegs in the fridge full and I have a 2 tap setup on the front of the fridge. I did changeover the taps on the 4th day a few times to try different kegged brews.
Is it possible I had some cross contamination back into the effected keg ?
The lines all have quick connects on the and I figured that since the kegs are pressurised nothing would go "back" into the kegs.
Its a bit of a mystery and I'll no doubt have to ditch the keg contents, but I just don't want it to happen again.
Cheers,
Andrew
:unsure:

 

[NewtownClown]

could it be the tap/lines are dirty?

 

[Liam_snorkel]

is the tap hooked up to the correct keg? h34r:

 

[Chuckie]

Tap lines were originally flushed with sanitised, but not in between changing between kegs. ie Beer from one keg was in the lines when changing kegs. Yep, tap is hooked up to right keg.

 

[mmmyummybeer]

Seems strange to go that bad in one day. Do you clean your lines regularly? That's what I'd look at first.
The beer will flow back when swapping kegs if you hook a keg up under a higher pressure then up to a keg of lower pressure, as the pressure in the line will push back into the lower pressure keg until the pressure equalises. Shouldn't be a problem for contamination though if the lines are clean and all the beers good, more of an issue is getting your super hoppy IPA in your English mild etc.
Have you cleaned all the lines and tried the keg again or tested the keg itself.
Also has anyone else tried the keg, the sweetness could be diacetyl which can be from oxidation and infection especially dirty beer lines. Some people can be supper sensitive to it while other people can't taste it at all. No idea sorry on the BO?
Also another trick which someone posted here is to wash your glasses with bicarb and not in the dishwasher. Try the same beer that's regularly going through the dishwasher with one you regularly have washed with bicarb and rinsed , it blew me away when I tried it. It can make a big difference if you've had a hoppy beer too long and the hops have dropped out.
Anyway sorry probably a bit OT and not much help, and hope your the future kegs stay delicious.

 

[Chuckie]

Should I be stripping down and cleaning the beer taps when I change kegs, or is running santiser through them enough ? I don't think I can easily strip them down, they are Celli taps bolted to the front of the fridge.
Do I also need to pull the keg spigotts apart when putting a new brew in an empty one ? I've just been cleaning inside the keg and running santiser through the spiggots.
I opened the effected keg and it didn't smell as bad as the beer from the tap (could be wrong about that though). So I resealed it, purged the 02 attached the CO2 lines and ran santiser through the beer line.
I'll leave it for a few hours and taste test again.
Thanks for your advice guys. EVERYTHING is helpful, so don't hesitate to put in your 2c worth.
Cheers

 

[manticle]

At least flush them with hot PBW or sodium percarbonate, rinse, then starsan. Don't just starsan - you need to clean first.

 

[Chuckie]

I usually clean them out with clean water, then soak them overnight full of sodium percarbonate solution, rinse, then I give them an hour full of Phosphoric Sanitiser and rinse again.

 

[SnakeDoctor]

What works for me is a few litres of hot sodium perc in a keg (that I also happen to need to clean) through each tap, rinse the keg properly, make up a few litres of sanitiser in the keg (because I need to sanitise the keg anyway), through each tap again, done.


I am pretty lazy though.