Fruit Flies

[broombrew]

So I bottled a 5 gal batch of my amber last weekend. Problem was I didn't realize until I was almost done that I didn't have quite enough caps. So I quickly sanitized a 1 gal jug and filled it from my bottling bucket and put an airlock on.

Now, a week later, I bottled that last gallon. Put the bottles in a box and started cleaning. This is when I noticed what looked like pieces of rice stuck to the inside of the jug. Closer inspection and they look to be larvae of some kind. Some forum searches here and my guess is from fruit flies.

What should I do? I assume that the first round of bottles will be fine as I didn't notice anything then, so they must have made their way into the 1 gal jug would be my guess (and hope). Should I keep everything and just let tasting be the judge? Should I not even bother with the bottles that I know have bugged beer and pour those out now?

 

[ChillWill]

I've been to a brewery where some fruit flies were in the fermenter, the guy didn't seem too bothered, but he was hardly a pro brewer. Might turn your beer a bit vinegary?

 

[Calder]

If it tastes fine, drink it. There are no known pathogens that can survive in beer.

You already had alcohol in it, which will protect the beer. The biggest problem might be actobacteria in the presence of oxygen = vinegar. You will know if you have vinegar, and it will not hurt you, just make the beer un-drinkable.

 

[FatherJack]

Funny that this post should appear today.

I woke up this morning, ironed my shirt and looked at my bucket o saison. In the S type airlock was a fruit fly.

Apparently the beer is so good that he couldn't wait to get into it.

 

[GoHawks]

I was working in a lab once... pouring TSA plates to grow bacteria on. The media is first sterilized in an autoclave then poured into dishes and allowed to cool/solidify.

Well.. one day I was pouring plates and a fruit fly flew into my hot media. I put the plate aside (covered) and left if on my bench top. About 2 weeks later it was absolutely FULL of growth... both aerobic and anaerobic species were actively growing. Those little guys have a ton of stuff in/on them.

 

[prrriiide]

Those little guys have a ton of stuff in/on them.

Bet my stuff is meaner than his stuff. The human immune system is a thing of grotesque beauty.

 

[betarhoalphadelta]

I've had two batches attacked by fruit flies (oddly, both used rye malt). This was a while back when I fermented in a 20 gallon wine fermenter, which is a euphemism for a food-grade garbage can. The lid did *not* seal.

The first batch wasn't caught in time and had soured, and had to be poured. The second batch was caught pretty much immediately, and was crash-cooled to ~33 degrees. That stopped any growth of anything nasty, and the beer was kegged and turned out fine.

I'd mark all the bottles from the 1 gal jug to be able to identify them. I'd let everything carbonate, and then I'd get them in the fridge IMMEDIATELY and assuming it tastes okay, drink them quickly. Assuming any nasties haven't had time to grow to the point where they're affecting the flavor, the fridge should retard any future growth and the batch will be drinkable.

If you start tasting them and even the un-marked original bottles taste like vinegar (or something else bad), then you might have a full drainpour on your hands. But I'd proceed as if it'll be okay until you have evidence otherwise.

 

[jtejedor]

I have heard they can turn beer into vinegar pretty quick.

 

[cincybrewer]

I have heard they can turn beer into vinegar pretty quick.

I've noticed that fruit flies love beer. It can be a good way to get rid of them. I've had 20-30 fruit flies in my beer that I've left out (on purpose)...and yes, after a few days it gets pretty nasty and has a harsh vinegar smell.

 

[Cosper123]

Bet my stuff is meaner than his stuff. The human immune system is a thing of grotesque beauty.

Yes it is, and often times that beauty manifests itself in very painful and annoying ways...like vomiting...or when it indescriminately nukes your throat and sinus cavities to get rid of a pathogen, etc. I mostly concern myself with vomiting

But yes rarely will those little bastards have anything that will survive the acidic conditions of the stomach. Knowing this I still don't think I could drink that, maggots and all....

 

[broombrew]

Yeah, this is all pretty much what I'd figured. If the 1 gallon that I had to rack off and bottle after was bad, I wouldn't be too sad. I mainly just don't want the other 4ish gallons to be bad as well. So I hope the bad stuff took place in that 1 gal jug.

 

[jmhart]

I've got a sour porter going in my basement right now that has ~30 dead fruit flies in the airlock....I'm hoping they flew in from the oustide and not the inside. The beer's a bit too dark to tell.

Eh, whatever. I'll find out in 6 months.

 

[jtejedor]

You guys are brave I don't know if I would sip some dead fly ale.

 

[jonmohno]

Keep in mind if you have an infection,its a bacteria culture eating sugar causing sourness and ultimately overcarbonating your beer, i would keep an eye and refrigerate those after carbonation, i had an infection,white flaky( crusty,paint like) layer on top and i think this is from fruit flys? i could be wrong about the cause,but just tonight i got twice the carbonation when checking one so im sticking all of them in the fridge. This was my first visible infection, i definatly fear the bottle bomb and plan on never having one.

 

[FireBrew63]

I recently found fruit flies in the airlock of 1 of my fermenters and fortunately none made it any further. I have since taken a small bowl, filled it w/ 1/2 cup apple cider vinegar and a couple drops of dish soap and placed it near the air lock. The fruit flies go for this mixture instead of the airlock now and as soon as they touch it they drown.