I stepped up a starter last night and after a few hours this thing was foaming over like an animal…I lost a ton of yeast…I sprayed the jug down with star san this morning and replaced the foil…Now for some reason im worried about contamination…Is this something that i should worry about?
Worry? probably not.
The likely hood of you loosing a TON of yeast is remote. The krausen is a combination of yeast and proteins. My guess is more proteins than yeast.
Happens to me every so often, I have never had a problem. I started using Fermcap, really, really helps. It is cheap and easy to use.