Originally Posted by PintOfBitter
sour mustard sounds like lacto infection. the last hop addition is suspicious. your hops could definitely have carried some bugs into your cooling wort. hops aren't germicidal, though some may disagree.dry hop in secondary after the pH has dropped and theres some alcohol content. you'll get more aroma this way anyhow.
I would tend to agree with this. I only use a 25' chiller and after 20 minutes im below 100F.
Put the chiller in with 15 left in your boil and add your last hop addition no later than immediately before you turn off the heat and start chilling. the few moments of 200F= temps will sterilize any beasties in the hops.
There is nothing wrong with your old chiller. if its clean, its good. copper oxides, but the green stuff that forms on it is not good to put in your beer.
And like stated before, make sure that you have plenty of sanitizer around to throw cold side items in. I love Iodophor.