Ive got some questions about cleaning and keeping clean my new wort chiller, used it just once to chill my first batch and rinsed with hot water and then sanitized and let it dry. Also cleaned out my bottling bucket that i had used to sanitize multiple things for my first batch. After everything was cleaned and sanitized i put everything away, and put the wort chiller inside the bottling bucket because it took up less space that way…however there was apparently a few water drops left inside the bucket, which then settled to the bottom, the combination of the plastic bucket, couple drops of water and the copper coil, managed to get a blue-green build up on the bottom of my chiller and bucket. I then read in Palmers “How to Brew” that a 5% vinegar solution is good for cleaning copper, especially copper wort chillers… so i cleaned my chiller with vinegar and scrub sponge, the scrub sponge was not strong enough i used a little steel wool, the combo of the vinegar and steel wool took off the blue-green stains, but the steel wool was ruined within a day -rusted it out-(used soft sponge on plastic bucket so as not to get scatches)…so now that ive got the blue green crap off, after rinsing with hot water, im getting some black-ish looking water spots now …obviously need some advice on cleaning and keeping clean my wort chiller…and whats with these black water spots???..got to love the learning curve…
Could be iron specs from your scrubber embedded in the copper, forming rust. Or it could be a bit of copper sulfide. Either way, nothing to worry about. I generally just rinse my IC and hang it up to dry. The portion that is submerged in wort usually stays fairly shiny.
It’s sounds like rust. Don’t use steel wool on your brewing equipment, it will embed particles. If you have to, use a SS or copper scrubber. Just make sure it’s