What's your brew kettle and fermenter ?
"and some other copper elements"
What are they ?
I use 3 keggles (HLT, BK, MT) for the brew day and I ferment in a 10 gallon Corny keg.
The BK has a pickup tube and whirlpool "arm" of copper. MT is all stainless but there is copper tubing that carries the water from the HLT to my Phil Listerman brass whirly gig sparger (Circa 2002..... a real antique that you old timers will remember). CFC and IC are copper.
All malt stored in sealed HDPE containers (Vittles Vaults and other similar). Most batches are WY Barke Pils malt. I don't taste metal in the malt
I have loved my homemade copper CFC because hop pellets cannot clog it and I have always been worried that SS plate chillers would clog. Might be wrong? But the green oxide is definitely in my copper CFC and it seems logical that on my more delicate beers it could show up more in the taste. Any thoughts on plate chillers and clogs and / or stainless immersion chillers as part of my solution? Who is using these SS chillers and how effective are they vs copper? Also is it an expectation that pilsners can be a bit tinny??