Mold in Fermenter?

[TexasWine]

Last weekend as I was kegging a Saison I had brewed I noticed something that made my heart sink. Two fruit flies had made their way into the beer sometime during the month it spent in the fermenter. Sneaky little pests! I hoped for the best and went ahead and kegged.

Then I washed the bucket and noticed something odd on the bottom of the bucket. Little gray spots that resembled mold (picture below). Reached down to rub them and they didn't come up. Grabbed a dish rag and scrubbed it, and it was barely budging. Soaked in PBW and scrubbed again. Same result. So I finally applied a little more elbow grease with my rag and got them to mostly come up. Still kind of visible though.

Anybody ever see anything like this or have a clue as to what it is? Thinking I'm gonna scrap that bucket and repurpose it for something other than fermenting. It's a few years old any way.

View attachment 1433593937272.jpg

 

[Hello]

I think mold stains but if there was liquid in there then it seems odd to me that it would be on the bottom and not along the rim of the beer that was in there. Unfortunately between that and scrubbing plastic, I would replace the bucket.

 

[m_perci]

What did the beer taste like? If it was good, I would just consider myself lucky and clean the fermenter very thoroughly. Best of luck!