Green neutral spirits

[badger6724]

I have been doing neutral spirits for years using Shady's sugar shine recipe and this is the first time this has happened. My heads started out green and as the run progressed it eventually turned clear. I tasted my cuts and the taste is definitely off. Not necessarily bad (turpentine) but not my usual neutral either. I use a T-500 copper condenser and I disassemble it and soak the saddles in citric acid solution after about a dozen runs. I am still using the same saddles for over 150 runs which are stainless with copper at the top. Any insights on why this happened and solutions to keep it from happening again?