turbo_ale wrote:On the other hand John Palmer was talking about discolored copper wort immersion chillers and said something along the line, paraphrase, (when you put your discolored copper chiller in wort, then after boil it is shinier, the acidic wort cleaned the copper of oxides, where did it go, in the beer.) Now copper itself is not harmful in small doses, it's the oxides which could cause off flavors. So I think he was getting at cleaning the copper with PBW and the like to keep the copper shiny, and not dark or discolored.
Doesn't this also carry over for plate chillers or CF chillers? That oxide layer is going to be present unless you use something other than copper. If someone only brews twice a year I agree that it probably makes sense to dip or soak the chiller in something acidic to clean it before it goes in the brew kettle but if you're brewing every couple of weeks I can't imagine the layer of oxide is substantial enough to do much of anything.