Metalic flavours in beer

[jason.loxton]

I have a noticeable metallic flavour in an amber that I brewed, which also seems to be lurking in the background of a very dark American stout (harder to tell though). Checking out Palmer and the Interwebs, it looked like the obvious culprits were metal from somewhere in my process or my water. The water is hard here, but not noticeable iron-rich. Where the story gets interesting is that I had a bottle that I pulled off of the keg early on (beer gun) the other day, and it was fantastic. That eliminates nearly all of the possibilities, both obvious (e.g., boil kettle, chiller) and less so (e.g., old grain, weird oxidation, etc.). The only clear possibilities that could have impacted the material pulled later from the keg, but not early on, that I can think of are 1) an infection somehow captured during the bottling process (e.g., beer flowing back up the bottling line during a drop in pressure, etc.), or 2) (much more likely) the kegs themselves. I cleaned both of them with Oxiclean, and Palmer mentions that this can produce oxides in copper that can be dissolved into the wort. Presumably it also can in stainless. (Although there is no evidence of rusting.) He advises avoiding Oxiclean and/or rinsing with Starsan or another acid-based cleaner. Wondering if anyone else has had issues with metallic flavours popping up post-kegging and, if so, what the culprit was?

[jeffsmith]

Not much help to offer, but I use PBW to clean and StarSan to sanitize all my kegs and have never run into an issue.

[Tony L]

I would blame your water, unless you boiled in a new Al pot that wasn't properly passivated .
I have been using oxiclean type cleaners and Star-San for 7 years with my kegs and never have had a problem
like that occur.

And it could be a problem that you didn't detect until later in the conditioning phase. A lot of off flavours will not
show up until later in the conditioning.

[jason.loxton]

What's mysterious is that just the beer still in the keg has the flavour, not that which I bottled from the keg post carbonation. They have both been conditioning for the same time, in exactly the same conditions (with the exception that half was still in the keg). It is a bit of a mystery...

[akr71]

Highly hopped beers can produce a metallic flavor if the sulphate:chloride ratio of your brewing water is skewed toward the chloride.

[jason.loxton]

Interesting. My water is actually pretty high in sulphate, but it is also quite heavily chlorinated. I use camden tablets to remove the chlorine, which I think produces chloride as a product. I wonder how large that contribution would be...

[Dirt Chicken]

Possibly the chrome plating has started to dissolve off of your shanks and,inner faucets. I plan to get perlicks soon as they won't have this happen, I have been told that acid rich brews and ciders will not been good on standard taps and shanks for the long term. Once brass is exposed, you will taste it, and not the first pints off a keg, bit after new beer has sat in the hardware for a but. Don't know,if this is the case, my best guess

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[akr71]

Interesting. My water is actually pretty high in sulphate, but it is also quite heavily chlorinated. I use camden tablets to remove the chlorine, which I think produces chloride as a product. I wonder how large that contribution would be...

When I've noticed it, it was not off-putting in anyway. Drinking from an aluminum can is more distasteful.

I think DC is on to something.