I stepped up a starter last night and boy it took off quick! Within an hour the foam was blowing the foam stopper out of the flask!
So I put a washcloth over the stopper and rubber banded it down for the overnight.
I got up the morning and there was this yeasty looking sludge all over the stopper and squeezed through onto the washcloth. It’s the same stuff that forms after a blowout in a fermenter.
Is that stuff yeast or is it just a sludgy bi-product of the foam?
It looked and smelled like yest, so I scraped it off an put it back into the starter.