I made a yeast starter and didn't touch it for a couple of days. I took the plastic bag I had wrapped around the mouth of the growler I was using to cover. I forgot to wrap it around the mouth, only covered the growler. As I took the dog for a walk, some fruit flies got inside the bag that covered the growler. I replaced the bag and put the growler in the fridge overnight. I decanted in a bowl this morning and inspected the yeast: no flies in either. What's your verdict?