Originally Posted by Psych
Note that I've heard Star San can muck up the stainless steel after a (long) while. I don't know the validity of that statement but have seen it floated around a number of times here when folks have stored Star San in a keg.
If it's no worry then cool deal, so long as it doesn't foam all to heck on you when you dispense!
This piqued my curiosity. I keep a Cornie full of StarSan much of the time for sanitizing and purging my other kegs. I push the StarSan into the keg being sanitized, then push it back with CO2, so that the keg was purged of air and has only CO2 and a little StarSan in it. It happens that that keg is empty now, so I rinsed it and took a look inside. That keg has a satin appearance all the way up, without any evidence of the StarSan level. I looked at the other 3 kegs I have clean and empty right at hand, and one other had a satin appearance, while the other two had more of a mirror appearance. The StarSan keg is a Firestone Challenger VI, while the rest were actual Cornelius kegs. It feels smooth to the touch. I can't say that I see a convincing difference.
Incidentally, I have kept StarSan in that keg in the dark for about 3 years, changing it perhaps once a year. I have checked it's pH with pH paper, and it has stayed at 2. I had come to understand that at a pH of 3 or below, StarSan is still good to use, even if cloudy. Mine has stayed clear.