Bottle cap soaking causing metallic off-flavors?

[mywifehatesmybeer]

I've searched the threads, and I've surfed the web, and I can't figure out why many of my brews seem to have a metallic after taste. It's occurred to me this morning, though, that I store my bottle caps in a Star-San solution along with some other odds and ends (stoppers, air locks, etc.). They sit there from when I purchase them to when I cap bottles, and I was thinking maybe that could be the culprit?

Luckily, the metallic taste isn't so awful that I won't drink the beer (SWMBO disagrees, hence the username), but I sure would like to narrow down what it could be in order to get rid of it.

 

[flars]

Without having any other information, I would hazard a guess the metallic taste is more likely to be from your brewing water rather than the bottle caps.

Sanitizing with Starsan takes less than two minutes, but storing your equipment in the sanitizing solution can cause some degradation, especially to plastics.

 

[chewse]

I've searched the threads, and I've surfed the web, and I can't figure out why many of my brews seem to have a metallic after taste. It's occurred to me this morning, though, that I store my bottle caps in a Star-San solution along with some other odds and ends (stoppers, air locks, etc.). They sit there from when I purchase them to when I cap bottles, and I was thinking maybe that could be the culprit?

Luckily, the metallic taste isn't so awful that I won't drink the beer (SWMBO disagrees, hence the username), but I sure would like to narrow down what it could be in order to get rid of it.

I think you have hit on a point. The last couple of brews I've done, I have used left over caps from previous brews. I noticed that on a few of the caps, rust had started. This, I believe, was caused from previously soaking the caps in Star San and drying them off but not used. The Star San may, directly or indirectly, cause the metal on the inside of the caps to break down allowing for rust.

 

[Subdivisions]

It's a mild acid so it could eat away any oxidized metal layers that are protecting it. Star san works in minutes. No need to leave them soaking for long periods.

This thread seems to verify what you're seeing.

https://www.homebrewtalk.com/showthread.php?t=485477