You haven't had much help there have you, probably too late for you now but if any body else comes here same as me looking for answers as to why my beer went bad in 3l pet bottles with a pvc dip tube inside which smells awful (same as beer tasted) and gone from clear to white.
Read a few other threads on here mainly blaming chlorine in the water for the chlorophenol but my trouble with that is my beer has been ok in polythene and cony kegs with the same water.
"So, as "a rule of thumb," in any brewing system, it is wise never to let chlorine come into contact with beer at any time and, most of all, to never use chlorine-containing compounds in beer lines because of the overall risk to beer flavour"
Is the c in pvc being chlorine the reason, the beer phenols are reacting with this, seems to say no to PVC pipe which is annoying as i bought the pipe from homebrew shop specially. Also worrying is I use the same pvc pipe in the high level tapped kegs with floats, perhaps not been noticeable as the ratio of immersed pipe to beer is much less ie. same more or less 10" of pipe (not all submerged) but 23L against 3L pipe almost completely submerged.
I don't think you can get PET pipe so going to try polyprop or nylon next, if they go bad then it's stainless some how.
