Author Topic: First Time Kegging - Metallic Off-Flavor  (Read 7285 times)

Offline tschmidlin

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Re: First Time Kegging - Metallic Off-Flavor
« Reply #15 on: March 03, 2012, 04:28:45 PM »
That's not actually what he said.


" Feb 24 - Turned CO2 back on to serving pressure & drew samples...both beers tasted great
 Feb 25 - Poured pint of each & new metallic off-flavor in aftertaste was present (tried the Scottish Ale out of a bottle & it tasted great, no off-flavor)"

On the 24th he pulled samples which would have been line contents and they tasted great. My experience with line contamination is that I'll get a slug of bad beer first. After more is poured, the off flavor seems to subside.  It sounds to me like it's coming from directly the keg, but I could be wrong. This is why I always keep a cobra tap line handy for quick, alternate line testing.
I see what you're saying, but I disagree.  Since he didn't pull any beer when he first hooked up the kegs, the beer may not have been in contact with whatever is causing the off-flavor.  After pulling the first samples on the 24th it was in contact, and future samples initially taste bad but it clears up quickly when pouring.  If it was something in the keg it wouldn't get better after 6 oz, unless it was confined to the dip tube (which it won't be for long if that is the case).

He also says he "Disassembled, cleaned, sanitized, reassembled, & filled kegs".  But he doesn't say anything about doing the same with the kegerator.
Tom Schmidlin

Offline ctownbrewer

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Re: First Time Kegging - Metallic Off-Flavor
« Reply #16 on: March 05, 2012, 06:44:26 AM »
For the kegerator itself, I pumped hot water through the lines first to give them a good rinse. Then I pumped sanitizing solution through & let it sit for about 10 minutes. As it sat, I rinsed & sanitized the new forward sealing flow control faucets I bought along with the ball lock QDs.

I didn't do a beer line cleaner soak, since this was the first time any of the lines came into contact with beer...same with the kegs. I didn't do an oxyclean soak since they were brand new.

Offline bo

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Re: First Time Kegging - Metallic Off-Flavor
« Reply #17 on: March 05, 2012, 07:12:33 AM »
For the kegerator itself, I pumped hot water through the lines first to give them a good rinse. Then I pumped sanitizing solution through & let it sit for about 10 minutes. As it sat, I rinsed & sanitized the new forward sealing flow control faucets I bought along with the ball lock QDs.

I didn't do a beer line cleaner soak, since this was the first time any of the lines came into contact with beer...same with the kegs. I didn't do an oxyclean soak since they were brand new.

So you did this prior to sampling the suspect beer, correct?

Offline ctownbrewer

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Re: First Time Kegging - Metallic Off-Flavor
« Reply #18 on: March 05, 2012, 09:53:41 AM »
Yes. However, I just realized I mis-typed something in my timeline. It should read like this...

- Feb 23 - Put kegs in kegerator for 24 hours to cool to serving temp (didn't hook them up yet)
- Feb 24 - Cleaned/sanitized kegerator lines, faucets, QDs...hooked up kegs & sampled, both tasted great
- Feb 25 - Poured pint & noticed the metallic flavor
- Mar 2 - Conducted (3) 3 oz sample test & found samples 1 & 2 had metallic flavor, but it cleared up in sample 3

Do you have any idea of exactly how much beer would be sitting in the lines at one time? My lines are 3/16" in diameter & about 5.5' long.

Offline bo

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Re: First Time Kegging - Metallic Off-Flavor
« Reply #19 on: March 05, 2012, 09:58:58 AM »
For that length hose it's only about an ounce.

As I suspected, this isn't a dirty line problem.

Offline euge

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Re: First Time Kegging - Metallic Off-Flavor
« Reply #20 on: March 05, 2012, 10:03:20 AM »
Was there any sediment? Sometimes yeast/sediment tastes a little or a lot metallic. Hops too. So the first few glasses sometimes have that raunchy metallic flavor.
The first principle is that you must not fool yourself, and you are the easiest person to fool. -Richard P. Feynman

Offline ctownbrewer

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Re: First Time Kegging - Metallic Off-Flavor
« Reply #21 on: March 05, 2012, 10:16:12 AM »
During my (3) 3 oz pour experiment, there was no sediment that I noticed. The only sediment I ever had was in the very first 8 oz pour that I dumped.

I'm thinking maybe the 1 oz of beer in the line was enough to make that first 3 oz sample have a nasty metallic flavor. Then the second pour basically rinsed out some of that residue still in the line, which is why the metallic flavor was very subtle in that one. Then the 3rd sample tasted normal.

Does this make sense or do you think it could be something else? I'm stumped because that 3rd 3 oz pour matched the flavor profile of my bottled version.

Offline bluesman

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Re: First Time Kegging - Metallic Off-Flavor
« Reply #22 on: March 05, 2012, 10:39:32 AM »
During my (3) 3 oz pour experiment, there was no sediment that I noticed. The only sediment I ever had was in the very first 8 oz pour that I dumped.

I'm thinking maybe the 1 oz of beer in the line was enough to make that first 3 oz sample have a nasty metallic flavor. Then the second pour basically rinsed out some of that residue still in the line, which is why the metallic flavor was very subtle in that one. Then the 3rd sample tasted normal.

Does this make sense or do you think it could be something else? I'm stumped because that 3rd 3 oz pour matched the flavor profile of my bottled version.

It's possible. Try either cleaning or replacing the lines to isolate that variable. It's quick and easy.
Ron Price

Offline bo

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Re: First Time Kegging - Metallic Off-Flavor
« Reply #23 on: March 05, 2012, 10:44:37 AM »
Am I missing something, but wasn't this a new kegerator and new lines?

Offline ctownbrewer

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Re: First Time Kegging - Metallic Off-Flavor
« Reply #24 on: March 05, 2012, 11:10:54 AM »
Yes. Everything was brand new out of the box when the new kegerator arrived Feb 20th...Maybe they lied on the website when they said the lines were beverage grade.

Offline bo

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Re: First Time Kegging - Metallic Off-Flavor
« Reply #25 on: March 05, 2012, 11:38:12 AM »
It was new AND you cleaned it. I don't have a answer as to what the problem is, but I still don't think it's a line problem.

Offline tschmidlin

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Re: First Time Kegging - Metallic Off-Flavor
« Reply #26 on: March 05, 2012, 11:22:49 PM »
During my (3) 3 oz pour experiment, there was no sediment that I noticed. The only sediment I ever had was in the very first 8 oz pour that I dumped.

I'm thinking maybe the 1 oz of beer in the line was enough to make that first 3 oz sample have a nasty metallic flavor. Then the second pour basically rinsed out some of that residue still in the line, which is why the metallic flavor was very subtle in that one. Then the 3rd sample tasted normal.

Does this make sense or do you think it could be something else? I'm stumped because that 3rd 3 oz pour matched the flavor profile of my bottled version.
I think this is right.  It is pretty easy to test - get yourself a picnic tap and some line, hook it up and pour three samples.  Then hook it back up to the kegerator and do the three samples again.  Do them in that order.

If the picnic tap samples taste bad, it is in the keg/dip tube.  If they taste great, it is not there.

If the picnic tap samples taste fine but the kegerator samples are bad, it is between the keg and the faucet.

If all of the samples are good it was somewhere in the system but would appear to be gone by now.

Even if it is not caused by microbial contamination, there could be exposed metal somewhere that is causing the off flavor.
Tom Schmidlin