Quote Originally Posted by edcculus View Post
FWIW, I was curious about this too a while back, so I just set aside a little developer and stop bath and slowly mixed them. The color slowly turned muddy to purple as I added more developer. I suggest you try this simple "experiment". Then you will know exactly what to look for.
Great idea, and odd that I didn't think of it myself because that is something I'd normally do. I think I was trying to save the stop, but am certainly not against sacrificing some to learn.
I've about 500ml of 9-month-old D-76 that is forming some weird strings, plus I'll be mixing fresh developer soon and running some test rolls. I'll dump this into some a bit of old 9-month-old stop so I can finally see what it looks like when exhausted.