Metallic taste from keg

[jbsg02]

I think I have a keg issue. I brewed an IPA and put it's been in the keg about 10 days. The first couple of days, the beer was GREAT, I was really excited to have 5 gallons of it, now I'm afraid something with my keg/CO2 has ruined my batch.

The flavor is very metallic and leaves the tongue very dry. But this only occurred within the last few days, so I know it isn't an issue in my brew day process.

Some people say carbonic acid will cause this, but I left a glass out and swirled it around until I got a lot of the CO2 out, and the metallic dryness was still there.

I had read someone mentioned they got this flavor when they were nearing the end of their CO2 bottle, and mine is about empty. I have a hard time understanding how that could be a cause though.

Maybe there is rust in my keg? Anyone else have a great beer turn metallic in their keg?

 

[thargrav]

This is almost always due to over carbonation.

 

[jbsg02]

This is almost always due to over carbonation.

will it also leave that dryness on the tongue?

 

[jbsg02]

I poured a glass and let it sit for nearly 3 hours so the carbonation would come out of solution. It still has an unpleasant bitterness that leaves a dryness on the tongue that wasn't there the first few days in the keg.

Any other things that could cause this?

 

[TwoGunz]

I've gotten that with newly carbed kegs and also with particular yeasts-- I loved Notty for awhile until I noticed persistent bite that disagreed with my palette

 

[jbsg02]

I've gotten that with newly carbed kegs and also with particular yeasts-- I loved Notty for awhile until I noticed persistent bite that disagreed with my palette

It was really good the first couple days in the keg, when it wasn't fully carbed yet. Fermentation was good, 1056 with a starter on a stirplate. Bummed that it went south so fast in the keg. I have had several bad kegged batches lately and my last brew I bottled is really good.

 

[erikpete18]

I poured a glass and let it sit for nearly 3 hours so the carbonation would come out of solution. It still has an unpleasant bitterness that leaves a dryness on the tongue that wasn't there the first few days in the keg.

Any other things that could cause this?

Trouble is that what you might be tasting isn't CO2 (which would all come out of solution), but dissolved H2CO3. Its the H2CO3 (carbonic acid) that can give it the bitterness flavor. Given enough time all that H2CO3 will convert back to water and CO2, but its possible that just because all of the bubbles are gone, doesn't mean the carbonic acid is.

All of this isn't to say that there might not be something else wrong. But, if I'm looking for the simplest explanation (and also as it turns out the simplest solution), I'd have to guess its just a carbonation thing. Give it a week or two to equilibriate everything, then try it again and see if its still tasting off. On a similar topic, I didn't see if you'd mentioned how you carbed this. Did you do the set-and-forget, or shaking method?

 

[jbsg02]

Trouble is that what you might be tasting isn't CO2 (which would all come out of solution), but dissolved H2CO3. Its the H2CO3 (carbonic acid) that can give it the bitterness flavor. Given enough time all that H2CO3 will convert back to water and CO2, but its possible that just because all of the bubbles are gone, doesn't mean the carbonic acid is.

All of this isn't to say that there might not be something else wrong. But, if I'm looking for the simplest explanation (and also as it turns out the simplest solution), I'd have to guess its just a carbonation thing. Give it a week or two to equilibriate everything, then try it again and see if its still tasting off. On a similar topic, I didn't see if you'd mentioned how you carbed this. Did you do the set-and-forget, or shaking method?

I did some light swirling when I first put it on gas, nothing vigorous. Had it at 30 psi for the first day then released gas and hooked it back up at 10 psi.

Interesting to hear your carbonic acid theory, I will give it some more time. Is this something common with force carbing?

 

[erikpete18]

It doesn't sound like its overcarbed, but it should balance out over time. I think the carbonic acid also reacts with other stuff in the beer at first, giving it some of those flavors. I know my first keg or two I was "sampling" and "checking for carb levels" right after I put it on gas and noticed a distinct bite. I can't say that it was carbonic acid or yeast in solution, but anymore I give it a good 3 weeks at serving pressure before I try any, and haven't had the problem since.

 

[masonsjax]

Some of my early beers that were lighter styles had a slight metallic taste which ended up being the unfiltered well water I was brewing with. I switched to filtered water and the flavor vanished.

[edit] I have also noticed a slight metallic quality when I use Amarillo hops as a flavor addition. I like it for dry hopping, but not so much for flavoring. I've only noticed it with Amarillo.

But yeah, you're probably tasting carbonic acid. Some people are sensitive to it.

 

[jbsg02]

Some of my early beers that were lighter styles had a slight metallic taste which ended up being the unfiltered well water I was brewing with. I switched to filtered water and the flavor vanished.

my water is good here, I used it before with good results, and this same beer was great the first 2-3 days in the keg

 

[jbsg02]

Update on this, the beer has gotten a lot better over the last week or so. It's still not as good as it was the first couple days in the keg, but, a lot of that metallic astringency has gone.

 

[gabrox5150]

it may well be metal from the keg dissolved by carbonic acid in trace amounts yet leaving bad aftertaste. I had that issue with coca cola like drink (pH close to 2,5) I was making and left it in metal container. The before/after storage in the container was abvious in the metal taste the container brought. I was brought to this page looking for ways to eliminate this contamination, my first track of solution would be using a high acidic solution like 2,5pH to buffer and neutralise the metal on the surface of the container, the problem is metal finishes to turn black in contact with acid and smells like burnt so there must be a good in between, not easy to find I think.