I've recently bought a nice 30qt stock pot, and had to modify my old double wort chiller (it was two coils I fashioned and connected with tubing). Now that I only need to use one kettle rather than two, I refashioned the two pieces of copper to be one unit. I used flux, solder and a coupling to connect the two pieces together. Is this potentially toxic? I'd think since those things are used in the copper pipes for drinking water in homes that it wouldn't be, but I'm not sure.