Confession: I freak out all the time.
So it was a regular Sunday night, I was accustomed to a lack of activity from the airlock on my Batch 001 sour ale. Then as quickly as could be, white dots had formed, I was sure this was mold, how could it be anything but disaster?! I checked, airlock in place firmly, liquid topped off, but there it was, something new on top of my fermentor long after I thought things were done. I was freaking out. I did what any sane person would do, I consulted Michael Tonsmeire (TMF) an expert in the field of sour ales.
(Please read more after the break.)
My freaked out Email (I edited out my fan boy gushing over his blog):
I am making a blueberry sour from jolly pumpkin dregs. The fermentation of the beer went very well. I added blueberries on July 1st and they have been hanging out since then. This evening I noticed what I think is white mold growing on top of the 4 pounds of blueberries. I recall reading on your blog that white mold wasn't too concerning you just rack from under it or pour it off. I think it was in your post on spontaneous fermentation starters. I have attached pictures. I am hoping you can tell me if this is mold and what I should do about it. I tried to get a good picture but it has been hot here and there has been a lot of condensation on the inside of the carboy.His calm reply:
It is hard to make a definitive identification from pictures, but IPhew! I don't know what it is or isn't but the hand of experience says, relax. It's nice to see people within the community giving of themselves to help fellow enthusiasts. I was anxious because of the 25 dollars in materials and the time invested, but I am doing things right so a mold infection is unlikely.
would bet it is just yeast or bacteria from the JP dregs. If you have
kept a filled airlock firmly in place the fermentation of the berries
should have produced enough CO2 to prevent mold from growing this
quickly. I'd just leave it alone until you are ready to bottle. I've
been a bit freaked out by some things I've seen growing on floating
fruit, but so far none of them have caused problems.