I know that exposed brass on a tap faucet can give beer a metallic flavor, but will a copper immersion chiller used for wort chilling have the same effect?
Trace amounts of copper are vital for yeast health and good foam; I think you’d be very lucky if a copper chiller contributed even that, let alone enough to affect taste. And an IC is way easier to clean and sanitize than a plate chiller, which could really affect flavor. RDWHAHB.
You can use 1/2 tsp of Brewtan B 1 minute prior to inserting the immersion chiller (at 15 min prior to flameout) to chelate the metal.
But this really is of benefit only if you have already done the full Low-Oxygen regimen and are worried about the possibility of a slightly increased chance of (primarily ferrous) metal ions contributing to oxidation reactions months later in storage or in package. As to the original question of whether a copper IC can contribute a metallic off flavor, no. If you’re not brewing LoDO, copper is either neutral or good.
I was unaware that Brewtan B is only useful when used in conjunction with full LODO regime.
…but regardless, I guess it doesn’t matter because it won’t remover copper flavor because the IC doesn’t add any.
I’m just saying that the amount of copper the IC will contribute is probably insignificant unless you’re working to achieve all those goals. Commercially, gallotannin is usually only added to the conditioning tank to precipitate haze-active proteins, with the added side benefit over other possible agents of removing metals that might contribute to oxidative reactions downstream (after those metals have potentially made positive contributions.) Even there, this is pretty far down the list of levers for maximizing shelf stability under adverse conditions. So, I don’t think most homebrewers need to worry about chelating the copper from their IC. If you do, BTB will do it. Of course if you have a lot of metals in your water, chelation is a great application for BTB no matter your process and priorities. BTB may still have other advantages for you, like upstream protein removal. That’s just how I view the issue of copper, and I’m trying to focus also on the question of metallic tastes.
A bright and shiny copper immersion chiller might add enough copper to your wort, but I let my old chiller get nice and dull colored and that oxidation/organic layer helps avoid significant copper transfer. Don’t worry about this.
I agree with Martin.
The only issue I ever had with my copper coil (besides when it started to leak and I replaced it) was when it started turning green. It only turned green when it sat unused for too long. That was always fixed by a good soak in StarSan. After the first “clean” use it was dull and ugly again. Never noticed any flavor contribution or storage issues.
Paul