Off flavor question

[arringtonbp]

I brewed an irish red quite a while back (7-8 months or so). It was clearly infected when I bottled it (pellicle, cloudy layer on top with quarter-sized bubbles). Oddly enough after it carbed up and cleared up, it turned out to taste pretty nice....

EXCEPT.....


It has a bad bitter metallic aftertaste. What type of beer infection can cause this? Is it possible it's not from an infection, but from a temperature or other type of issue?

 

[JPHussey]

BJCP Beer fault guide suggests that metallic off flavors of iron, copper, coins, or blood are cause for the possible actions:

Check water for metallic ions. Reduce water salts. Check equipment condition for rust. Make sure stainless steel equipment is properly passivated. Fully rinse sanitizer. Try using RO water and add salts as needed.

I had this off-flavor once and unfortunately was a new brewer so wasn't taking good notes. Looking back I think it was probably from a new aluminum pot I had.

It doesn't seem that infection is a cause of metallic flavors...infection seems to cause things like vinegary, sulfury, sour/acidic, plasticy, and DMS off-flavors, to name a few.

I know that metallic off-taste is pretty damn distinct so I'd check those things I listed above first.