to eliminate your kegs/lines/gas/couplers/etc as the source of your "infection"
The kegs are thoroughly cleaned and sanitized. I can't get them any cleaner. If the infection is somehow lingering in the kegs then I will need to throw them out and buy new ones.
I know you have said that the problem has also been noticed coming out of your fermenters. BUT, this last one tasted great coming out of primary.
The key is that this was a brand new fermenter. Note that it did not become infected during primary. I also no longer store beers where I store grains and so when I dry-hopped this batch it also did not become infected - so that problem appears to be solved thanks to HBT.
So this tells me that if I ferment in a bucket that previously had an infected beer, the infection carries forward. Buying a new bucket proved that.
You are trying to figure out where the problem lies, but not trying many different actions, other than cleaning and saying "not possible in my system", to remedy the problem.
I don't know where this perception comes from. I am changing things around, using different water, buying new equipment, trying to eliminate possible causes - sometimes even taking advice in this thread that I know will not make a difference. I have never said "not possible in my system" as you quoted me.
Infections take longer than 2-3 days to become detectable.
Do you have a source for this? Because I am extremely skeptical of this statement.
I know that you are frustrated - I certainly understand and sympathize with you, but I think you have thrown all of your eggs into the same basket by calling all of your beers "infected". I think your problem is best serviced, not by shooting down more advice from us on here, but by getting your "bad" beer to someone knowledgeable who can figure out what the "off" flavor is. I'd be happy to help if you want a stranger from NY's advice. Good luck
The off-flavor is an infection. There is no doubt in my mind that it is because there is no other explanation that fits all the evidence.
If it isn't, then explain why when I use a bucket that had previously contained "infected" beer, the next beer in that bucket becomes "infected" but if I buy a new bucket from the LHBS, the beer is fine? If that's not an "infection" then what in the world is it?
Besides that, no one in this entire thread has presented a plausible alternative. Unless you count the water profile issue, but it was never plausible for me. I brewed the batch with distilled water and 6 teaspoons of gypsum just to prove to you guys that the water isn't the problem.
Remember that this flavor is unique and unmistakeable, and nothing I have ever tasted in a commercial beer.