[denny]

I've gotta say I've never heard of anyone confusing tannic with metallic. And overcrushing along e will not cause either.

As long as you've been around surely you've heard someone misinterpreting an off flavor or palate sensation...... I'm sure its pretty dang common.    This is from Cicerone.org

Astringent: Tastes/Smells Like: Tart, vinegary, tannin, drying,puckering sensation, may feel powdery or metallic in the mouth, like sucking on a grape skin or a tea bag

#Wheaton's Law

Yep, I've heard lots of them. Just not that one.

[Fire Rooster]

If youdic can reach out to some trained judges to taste the metallic beer- they might offer better ideas than "spit-balling" on a forum.  Let us know if the equipment changes make a difference.  I use a copper immersion chiller and have no issues that have come up.

My thoughts.
Copper counter-flow chiller you have no idea what's going on inside, and stays wet
which would turn acidic over time.
Copper immersion chiller exposed to air stays dry therefore brown.

[denny]

If youdic can reach out to some trained judges to taste the metallic beer- they might offer better ideas than "spit-balling" on a forum.  Let us know if the equipment changes make a difference.  I use a copper immersion chiller and have no issues that have come up.

My thoughts.
Copper counter-flow chiller you have no idea what's going on inside, and stays wet
which would turn acidic over time.
Copper immersion chiller exposed to air stays dry therefore brown.

I think you're jumping to a conclusion. It's a possibility but far from a sure thing. Many people use copper CFCs without problem.

[Big Harry Deehl]

My thoughts.
Copper counter-flow chiller you have no idea what's going on inside, and stays wet
which would turn acidic over time.
Copper immersion chiller exposed to air stays dry therefore brown.

I agree completely.  I see green when I flush it and after 20+ years of service, it's gotta go.  My copper IC is still going to be around because it still looks good and I might use it occasionally.  Also, I'm going to avoid 34/70 and be more careful with my sparge (temps, closely check SG of runoff, and ph to avoid tannin extraction).  Cheers!

[Fire Rooster]

My thoughts.
Copper counter-flow chiller you have no idea what's going on inside, and stays wet
which would turn acidic over time.
Copper immersion chiller exposed to air stays dry therefore brown.

I agree completely.  I see green when I flush it and after 20+ years of service, it's gotta go.  My copper IC is still going to be around because it still looks good and I might use it occasionally.  Also, I'm going to avoid 34/70 and be more careful with my sparge (temps, closely check SG of runoff, and ph to avoid tannin extraction).  Cheers!

This reminds me times as a child I would disassemble everything,
and then reassemble.  One time I couldn't figure out how to
reassemble.  After that, every time something new came into the
house, mother would warn me many times not to take it apart.

With that thought in mind, I'm much older now and wouldn't cut
the CFC in many pieces, just in half (LOL). Or the bare minimum
cutting a piece from the end to see whats lurking inside.

Cheers

[BrewBama]

I wouldn’t cut it apart

[ynotbrusum]

Some clarification on concepts here - feel and taste are two different things, of course.  Astringency is a feeling, for example.

[goose]

I'm not as sold on the copper theory as others seem to be

Neither am I.  My brewing system has copper in it for the RIMS system and I never get metallic taste in my beers.

I have also read that some copper in the wort is good for yeast health.  Eventually, I am going to have to replace the copper as the walls will become thin from the acidity of the wort.  But so far so good after 26 years of brewing and the copper remains bright and not green inside again from the wort acidity.

[Fire Rooster]

We have a rare opportunity.

Big Harry Deehl could become a legendary Myth Buster, and cut sections
from the "middle" of the Copper counter-flow chiller and post pics.

Cheers

[Fire Rooster]

fyi

HEALTH:
"copper concentrations exceed an action level of 1.3 ppm in more than 10% of customer taps sampled, the system must undertake a number of additional actions to control corrosion."
source = https://www.epa.gov/dwreginfo/lead-and-copper-rule


YEAST:
It's my current understanding that copper for yeast shouldn't exceed .2 ppm.

Cheers

[Big Harry Deehl]

We have a rare opportunity.

Big Harry Deehl could become a legendary Myth Buster, and cut sections
from the "middle" of the Copper counter-flow chiller and post pics.

Cheers

Maybe I will, but wherever the oxidized portions are in the coil may not be in the cut area.  This homemade CFC is over 35 feet long which is likely much longer (2x?) than most CFC coils available on the market.  Wherever the oxidation exists, the one thing I do know is the boiling water I recirculate through it turns light green.  Let me see if I can figure out how to post a picture of this beauty...... it's @2' in diameter!!  I've forgotten how to attach an image.....
https://photos.google.com/photo/AF1QipMQlJIHs1nQseHa1zDCR8ZLmro1VD5tNwh0Y6--

[Fire Rooster]

We have a rare opportunity.

Big Harry Deehl could become a legendary Myth Buster, and cut sections
from the "middle" of the Copper counter-flow chiller and post pics.

Cheers

Maybe I will, but wherever the oxidized portions are in the coil may not be in the cut area.  This homemade CFC is over 35 feet long which is likely much longer (2x?) than most CFC coils available on the market.  Wherever the oxidation exists, the one thing I do know is the boiling water I recirculate through it turns light green.  Let me see if I can figure out how to post a picture of this beauty...... it's @2' in diameter!!  I've forgotten how to attach an image.....
https://photos.google.com/photo/AF1QipMQlJIHs1nQseHa1zDCR8ZLmro1VD5tNwh0Y6--

That's assuming corrosion isn't throughout center section of pipe.

Can't view image.  This site is not user friendly to share images.
I believe you can't attach an image, you have to link to it, which I see you did.
You have to set permissions to the image your trying to share.
I don't post many pics because sometimes it works, sometimes it doesn't
Others post pics at ease with some app. I've seen some trying to post pics
and give up. Perhaps others will chime in to help.

Cheers

[Big Harry Deehl]

See if this works.... its a thing of beauty!

https://photos.app.goo.gl/s4bEaAZ8dRByVxHd7

[Fire Rooster]

See if this works.... its a thing of beauty!

https://photos.app.goo.gl/s4bEaAZ8dRByVxHd7

Looks just like my garage floor did early last year, floor paint color, wear and all.
Was looking to go with epoxy, but last summer went with polyaspartic.

[MNWayne]

I'm going a completely different direction.  What's your water stats?  What hops?