Is that verdigris?

[lari]

hi all,
after years of using my dull looking copper chiller i thought i'll make it sparkle again.(in hindsight i probably shouldn’t have done that) I used some barkeepers friend and a toothbrush. it came out looking gorgeous - all shinny like….for about a minute or so…
weird looking patches and spots started appearing. so decided to dunk it in some water/vinegar solution which removed the discolouration…but again, after rinsing and letting it dry these green looking patches came back. is this the dreaded Verdigris?
No idea what to do with it now. anyone?

 

[b-boy]

I can't tell. I usually soak mine in Star San for a few hours and it cleans right up. give t hat a try.

 

[k-moe]

Yes, that is verdigiris. Wash it off again with 50/50 vinegar and water, then rinse with water alone to neutralize. The reaction that makes verdigris happens when the copper is exposed to acids (or bases, but a different pigment is produced). I keep it at bay by spray sanatizing just before using my chiller, and rinsing the copper off with hot water after the wort has chilled.