Cleaned my hydra wort chiller for my next brew day. Soaked it for several hours in a hot PBW soak. Was this calcium sulfite?
Is your cooling coil made of copper? Looks like a chemical reaction with copper. That’s likely what caused it.
Good point yes a copper wort chiller. That’s the first time I have ever had blue water after cleaning my chiller. I noticed the chiller had a some brownish scum on the chiller before cleaning it yesterday. The PBW cleaned it well.
Copper sulphate is blue, if I remember from my chemistry class correctly.
What you are seeing is sulfated copper. Copper is the reason why blue crabs are blue.
Never had a blue crap. But after eating beets it’s bright red!