[jimmykx250]

I'm fermenting an ipa that's just about done when I noticed the airlock on top had dead fruit flies in it. Is this something any of you have experienced? I haven't noticed them in the house before so im not sure exactly where they are coming from. We keep all fruit except apples and oranges in the fridge and I checked right away and nothing there. The beer smells ok. What should I do to prevent this? Im kinda hesitant to taste the beer now. Any advise or opinions?
Thanks,

[dcb]

Yeah, I just had this happen on my last batch.  The little buggers were relentless this year, the worst I've ever seen them.  I can't figure out how they got in there, but I had 8 or 10 of them lying dead in the airlock when at about the two week mark.     I was ready to verify that it was time to bottle, so when I pulled out the airlock to draw a sample, I cleaned, emptied, and refilled the airlock.  I'm just now drinking that batch and there seem to be no ill effects. 

I wouldn't worry about it-- the airlock did its job.

[Jimmy K]

They are attracted to the smells of fermentation. Don't worry, that's what an airlock is for. Flies, bug, airborne fungus, etc land their instead of in the beer. It doesn't hurt to clean the airlock out.

[denny]

I've had one or 2 batches where I saw fruit flies in the airlock and the beer ended up infected.  I have no idea whether it was because of the flies in the airlock, or if some actually got into the beer.  I've always believed it was the ones in the airlock, even though that makes no sense!

[bengelbrau]

I wonder if some of those flies in the airlock might have been sucked back when the stopper was pulled off or the carboy was chilled enough to create a vacuum?

[erockrph]

I've had one or 2 batches where I saw fruit flies in the airlock and the beer ended up infected.  I have no idea whether it was because of the flies in the airlock, or if some actually got into the beer.  I've always believed it was the ones in the airlock, even though that makes no sense!

Do you use Star-San or alcohol in your airlocks, or just plain water? I've always assumed that a sanitizer would take care of anything that makes it through the airlock.

[bengelbrau]

I think star-san would take care of the cooties on the flies' feet, but I don't know about what they're hauling around in their guts.

[jimmykx250]

I always use star san and I use a 3 piece air lock so I don't see how they could possibly get into the beer. Anything is possible. After I found them I dumped and cleaned the airlock and used a 50/50 mix of star san and vodka in it. If the beer is infected it will be evident in the taste correct?

[brewinhard]

Fruit flies are notorious for carrying acetobacteria on their bodies.  If a fruit fly did make its way into your beer and there was oxygen present, the beer could take on a slight vinegar (acetic acid) note to the aroma and flavor.  You will taste this and sometimes see a thin pellicle on the surface of the beer from this as well. 

So you are saying that the fruit flies got in through the cover of the 3 piece airlock?  I have never seen that happen before.  I could see how they get into the s-shaped airlock, but 3 piece is interesting....Either way, the s-shaped airlocks have breathable caps that can be placed on top to hopefully keep out the flies in the future. 

[69franx]

I have seen fruit flies inside the three piece airlocks. These lids are also breathable and I guess they can still get through


Sent from The Alpine Brewery using Tapatalk

[dcb]

So you are saying that the fruit flies got in through the cover of the 3 piece airlock?  I have never seen that happen before.  I could see how they get into the s-shaped airlock, but 3 piece is interesting....Either way, the s-shaped airlocks have breathable caps that can be placed on top to hopefully keep out the flies in the future.

In my case, this is exactly what happened.  The only openings I can see are six tiny hole in the top of the cap, holes that seem far too small for the fruit flies.  They would have a lot of star san to swim to to get to the beer, and while I don't know for certain that none made that improbably journey, there were quite a few dead in the bottom of the airlock cup.

[Wrynn]

Those little buggers always find their way in. At least in my place. God bless air lock, however I always say that this time they won't be here as there is no way/ Blah blah. Out of thin air! I hate fruit flies -_-

[mainebrewer]

I sometimes get the flys in the airlock. Never had an infected batch yet.
Biggest problem for me is they like to hang out in the beer faucets.
So, the first pour of the day usually has me picking them out of my pint of beer.

[Slowbrew]

I had a crazy number of fruit flies in my basement a couple years back.  They had taken up residence in the floor drain beside my deep sink.  I ended up have to soak the drain, grate and exposed inside pipe with "Home Defense" stuff 2 or 3 times to kill all the little buggers.

I haven't had another bout with them since.  I did learn to be more vigilant with that drain though.

Paul

[morticaixavier]

I sometimes get the flys in the airlock. Never had an infected batch yet.
Biggest problem for me is they like to hang out in the beer faucets.
So, the first pour of the day usually has me picking them out of my pint of beer.

You can buy little caps for the taps (Hey I'm a poet!) or, alternatly just put a little bit of seran wrap over the end.