Vinegar Flies And Acetobacter

[manticle]

I have a finished brew which is just cleaning up on the secondary yeast cake before being cold conditioned (no room in the fridge).

I was just double checking stable gravity and sampling toaday when I noticed a little vinegar fly stuck in the thread on the side of the lid. I tapped the side which squashed the fly, tapped it out, removed the lid and immediately replaced with glad wrap. I then took the lid away, thinking to sanitise it and replace it. I noticed little whitish spots on the o-ring which reminded me of some acetobacter infection photos I've seen (top of the brew currently looks fine) and another fly inside the lid. Could potentially just be yeast from a healthy krausen but I don't know.

I took the o-ring out, washed it and used it to secure the glad wrap.

What I'm curious about is is this likely to be enough to give me vinegar later down the track or may I possibly have prevented infection? Obviously I have to wait and see but I have no experience with these little critters so I'm interested to read from those who have.

Cheers

 

[Darren]

Manticle,

Probably i would say. Chances are that you also have little maggots squirming in the "high-krausen line"

cheers

Darren

 

[MHB]

Drosophilidae link
Common fruit fly, they live on yeast so yes they love breweries.
Often called Vinegar Flies because they can spread other bacteria (like Acetic Bacteria) that attaches to them when they are foraging.
The white spots you noticed could easily be yeast colonies that have attracted the flies, or lots of other things that could be bad news.
View attachment 34180
No matter what they say I still dont trust the Red Eyed ones, I think theyve been into my beer.
MHB

 

[manticle]

Manticle,

Probably i would say. Chances are that you also have little maggots squirming in the "high-krausen line"

cheers

Darren

I'll have a squizz but the krausen on this one has dropped right off (finished fermenting at 1009 for a few days now).

Anyway it looks like I'll probably be drinking this one quickly and not giving any bottles away.

@MHB - neither of these two had red eyes. I remember high school genetics experiments involving breeding drosophila but only very vaguely.