I plan on making one of these for my temp controller probe. Will I get off flavors or other problems if I use copper tubing? I know its used for chillers but this will be sitting in my fermenting wort a lot longer than a chiller.
IIRC, copper will eventually corrode because of the acidic wort while in the fermenter. I couldn't tell you how much will happen if only a teeny bit of copper is in there, but not so good things can come of it : The Brewing Network: Metals that Affect Your Beer.