Metallic off flavours

[Brewer #334545]

Hey everyone,
I brewed a lager a while back, it was unfortunately a massive underpitch. It took 2 weeks to pressure ferment then I cold crashed for 2 weeks before kegging.
When it was chilled I took a few samples and sometimes notice a metallic aftertaste. Anyways when originally in the keg the metallic taste was very noticeable and disgusting, its a week later now and only on the finish or very noticeable through a bad pour thick head. Any ideas?
Im leaving on a work trip the next three weeks and hoping it’s solved by then. No new equipment for me this is just unexpected development.
Thanks.

 

[Minbari]

any copper in the fermentor?

 

[Brewer #334545]

No I’m stainless everywhere hot and cold

 

[Minbari]

No I’m stainless everywhere hot and cold

that was my only thought. I made a copper chill coil once upon a time. beer tasted like a rotten penny.

learned my lesson, went all stainless after that.

 

[HighVoltageMan!]

What kind of yeast? S23 can throw a metallic flavor under pressure. When yeast start to autolysis it can produce a metallic or even a meaty flavor.

Just another reason to hate S23.

 

[Megary]

Just a wild guess here…but does the flavor dissipate as the glass sits and warms up? I’m wondering if the beer is over carbonated. Excess CO2 can leave a bite that *might* be described as metallic.

 

[Ward Chillington]

Tell me about your water? Where did it come from and how did you handle it? What's the mineral content like?

 

[Brewer #334545]

What kind of yeast? S23 can throw a metallic flavor under pressure. When yeast start to autolysis it can produce a metallic or even a meaty flavor.

Just another reason to hate S23.

Escarpment Pilsner, I brewed a lager and kegged a couple days before, was a repitch. No metal taste on the last one

 

[Brewer #334545]

Tell me about your water? Where did it come from and how did you handle it? What's the mineral content like?

Detroit water ca < 40 ppm and everything else in the teens, treated with campden. 20+ batches and never had an issue

 

[Minbari]

Escarpment Pilsner, I brewed a lager and kegged a couple days before, was a repitch. No metal taste on the last one

how was the yeast handled before it was re-pitched? maybe alot of dead yeast?

 

[Brewer #334545]

how was the yeast handled before it was re-pitched? maybe alot of dead yeast?

I have a Kegmenter with a floating dip tube. I filter my lagers because I do double batches and have extra kegs sitting in my basement fridge that I can bring up and serve relatively quick and clear in the kegerator.
Once the floating dip tube starts to gurgle I just pour whatever is in the filter housing into a sanitized mason jar. It’s never given me issues before.
Would autolysis fade though? It’s has gotten from a unpleasant pint down to an subtle after taste in a week. I tried some locally grown Saaz and magnum this batch but I don’t know if hops could do something like this

 

[Brewer #334545]

Just a wild guess here…but does the flavor dissipate as the glass sits and warms up? I’m wondering if the beer is over carbonated. Excess CO2 can leave a bite that *might* be described as metallic.

It’s on 10 psi, fermented at 15 psi ~70F it’s natural carbonation was almost spot on. Don’t think carbonation is an issue

 

[HighVoltageMan!]

Some yeast don’t perform well under pressure. 34/70, Diamond and 2124 all are excellent under pressure. I had the same metallic flavor with S23. Over time, as the yeast dropped, the metallic flavor was reduced, but never went away completely.

 

[The Brew Mentor]

Sometimes it's easy to put a finger on things and sometimes, not so much.
Based on your original post and comments after, I'd go back to your "massive under pitch".
You stressed the yeast, they had to perform and reproduce under unfavorable conditions.
That and then you filtered this which can add another set of conditions and potential issues.
I'll bet most of the off flavor will fade in a few weeks, and then drink through it.
I drank through many not so great beers pondering what I needed to change earlier on.
Cheers,
Brian

 

[Ward Chillington]

Detroit water ca < 40 ppm and everything else in the teens, treated with campden. 20+ batches and never had an issue

I was going to suggest iron content in the water. Is there a chance that this city water changed a source or some line construction added iron sediment to the water?

 

[Brewer #334545]

Some yeast don’t perform well under pressure. 34/70, Diamond and 2124 all are excellent under pressure. I had the same metallic flavor with S23. Over time, as the yeast dropped, the metallic flavor was reduced, but never went away completely.

This was a repitch, no issues the first round.

 

[Brewer #334545]

Sometimes it's easy to put a finger on things and sometimes, not so much.
Based on your original post and comments after, I'd go back to your "massive under pitch".
You stressed the yeast, they had to perform and reproduce under unfavorable conditions.
That and then you filtered this which can add another set of conditions and potential issues.
I'll bet most of the off flavor will fade in a few weeks, and then drink through it.
I drank through many not so great beers pondering what I needed to change earlier on.
Cheers,
Brian

That’s my hunch also see how it turns out

 

[Brewer #334545]

I was going to suggest iron content in the water. Is there a chance that this city water changed a source or some line construction added iron sediment to the water?

Haven’t noticed anything in my glasses of tap water, the reports are only quarterly. No issues with a batch from 2 weeks before

 

[Ward Chillington]

Haven’t noticed anything in my glasses of tap water, the reports are only quarterly. No issues with a batch from 2 weeks before

Ok then...strained yeast is the consensus.