Two days ago I had some pretty large particles floating in my secondary and a pretty thick layer of yeast on the bottom. I decided that I would move it to another carboy and cold crash the beer to clarify. I sanitized everything, at least I think I did. Today there is a decent layer of yeast again and another layer about a half inch thick of dark gray settlement. Is this just from cold crashing or did my beer get infected? I know I will find out when I bottle, but I'd really like some reassurance sooner.