persistent metallic taste from kegged beer, even with water

Wondering if anyone can shed any light on this problem that has been plaguing me for months and months and months. If my beer sits in the line for more than a few seconds, it has a horrible metalic taste that is unpalatable. Tried many different lines, got new perlick taps, tried picnic taps, various disconnects, poppets, kegs, beer posts, etc. Did some tests using tap water today, and found the following:

1) Tap water is normally alkaline PH = 7.7. Once it touches the clean stainless inside a keg it drops to 6.7 or thereabouts. Thats even before i close lid and carbonate. Water taste is ok or maybe slightly different but i cant be sure.
2) tap water under co2 pressure gives same horrible metallic flavour as beer when left in line for a few minutes. PH of water is 6.3 afer being under about 10psi for few minutes, then gas released and water taken from keg (not under pressure, tipped out)

So there seems to be 2 irregularities. One is the PH drop when water is contact with keg, and the other is the flavour which doesnt appear to be related to the beer, given the water experiences it. Maybe my CO2 is contaminated???? Seems unikely but I have put myself through the mill and thats the only thing thats constant.

My process is sound and my beer is ok out of the bottle when naturally carbed. Please help! I'm trying to keep my spirits up but this is a tough one! I've read a few posts with similar problems but the original poster has never closed out the thread with a solution? Hope they didnt give up.

 

Could be carbonic acid from the CO2...???

 

Try something like this to eliminate the possible contamination http://www.northernbrewer.com/brewing/in-line-sanitary-filter.html

I use them on my CO2 tanks as it is cheap insurance.

 

try splittin a batch between keg and bottle if ur bottles are fine then it is ur kegs but if bottles are metallic tasting too try using store bought water and see what happens

 

I've got one of these lying around - will give it a try, thanks.

 

I'm having the same problem, did the sanitary filter work for you?

 

Believe it or not I haven't really solved it. I haven't convinced myself it could possibly be a contaminated co2 tank, which is still the same one from a year ago. I've just realized it could be overcarbonation so I am testing that theory at the moment.

 

I think I got the same issue hope some one can help

 

I had the same issue. Had to dump 5 or 6 batches until I fixed it. I never did find out what the cause was, but I eventually ran through my entire process and made about a dozen small changes, including building a keg cleaner to ensure the keg was properly rinsed, fermented cooler (proper temp control), changed the hose that connected the false bottom to the cooler in the MLT that I wasn't sure was food grade (my primary suspect), and I installed a CO2 filter. Huge relief to find that the next batch of beer was outstanding. Nearly gave up on this hobby over that issue...

I wouldn't hesitate to install a CO2 filter and put a check value on the gas line. Perhaps replace the regulator if you suspect that you've had beer pushed into it.

 

You say if the beer sits in the lines for a couple of minutes the beer taste bad. Usually that means your beer lines are the problem. Even with the most expensive beverage lines I could find, I still taste it. I have to pour out the first 2 oz of beer, and then I'm good.

 

Same issue.

Double batch: Kegged 5 gallons, bottled 5 gallons.

Bottled taste normal. Kegged taste like metal.

I JUST exchanged my Co2 tank and this was the first batch.

So what is it? I've been kegging for 6 years and never had this issue.I really feel like it must be a co2 tank issue.

I'm going to exchange the tank--has anyone else found that the the CO2 tank was to blame? Is it possible? Is there liquid grade vs welding grade Co2?