Hello HBT.
I use peracetic acid at work and it never causes problems with any copper it happens to inadvertently touch (chiller lines, cold water plumbing etc). I usually use povidone iodine at home for my home brewing.
Today I thought hey, why treat the ol' home brew setup to a little peracetic (which is all 304 or 316 stainless). During my boil I perform the usual CIP on my plate chiller, leaving it running through the boil. My process is once the boil is finished I connect up the transfer hoses while they are still full of sanitiser and start the transfer, running to drain until wort appears then switch to my fermentation vessels. This is handy because it stays sanitised until needed and the pump remains primed.
During my CIP/recirculation I notice that the peracetic solution rapidly turned blue. I'm guessing copper acetate? Plate chiller must contain copper plates or copper brazing? I dumped the solution, flushed it with water and set it going with my usual providone iodine solution and will continue the blue/brew day without sweating it too much.
But my question is, waa? Surely this can't be good for the plate chiller, the beer and my health? I'm going to assume yeast metabolises the copper during fermentation, so I'm not really concerned about that, but what I'm thinking is should I ever use peracetic to sanitise my plate chiller again? I can't believe it attacked it so quickly. I thought dilute acids were ok to 'pickle' brass and as such ok to use around copper to some extent. I thought that providone iodine was a mixture of phosphoric acid and iodine and to my mind, phosphoric acid is far more hardcore than peracetic acid.
I use peracetic acid at work and it never causes problems with any copper it happens to inadvertently touch (chiller lines, cold water plumbing etc). I usually use povidone iodine at home for my home brewing.
Today I thought hey, why treat the ol' home brew setup to a little peracetic (which is all 304 or 316 stainless). During my boil I perform the usual CIP on my plate chiller, leaving it running through the boil. My process is once the boil is finished I connect up the transfer hoses while they are still full of sanitiser and start the transfer, running to drain until wort appears then switch to my fermentation vessels. This is handy because it stays sanitised until needed and the pump remains primed.
During my CIP/recirculation I notice that the peracetic solution rapidly turned blue. I'm guessing copper acetate? Plate chiller must contain copper plates or copper brazing? I dumped the solution, flushed it with water and set it going with my usual providone iodine solution and will continue the blue/brew day without sweating it too much.
But my question is, waa? Surely this can't be good for the plate chiller, the beer and my health? I'm going to assume yeast metabolises the copper during fermentation, so I'm not really concerned about that, but what I'm thinking is should I ever use peracetic to sanitise my plate chiller again? I can't believe it attacked it so quickly. I thought dilute acids were ok to 'pickle' brass and as such ok to use around copper to some extent. I thought that providone iodine was a mixture of phosphoric acid and iodine and to my mind, phosphoric acid is far more hardcore than peracetic acid.
