A fly! Is it ruined?

[MattK]

Morning all,
I just took a sample (with a wine pipette) from my FV to check the gravity, and what did I find floating in the trial jar but a bloody fruit fly. Haven't a clue how it got in (if it even did) as the FV is sealed and airlocked. How screwed am I? Does one fruit fly equalacetobacter infection? It smells (and tastes) fine at the moment. Is there anything I can do to mitigate the risk? It's at 1.014 at the moment and slowing down:


Edit: I should add that it may have been there a while, as I'd taken most of the previous samples from the tap, but as today's was starting to get a bit heavy with yeast I decided to take one from the top where it was a bit clearer. I took a good look at the surface just now and there's no sign of any more.

[Bobba]

Nice graph
It'll be fine! no sweat If it's under airlocked, the fruitfly prob just jumped into the trial glass. And even then, you've got a bit of alcohol (and lower pH) going on in there now, which should take care of most things

[boingy]

Chances are it will be fine.
There is certainly no action you can take at this point to mitigate the risk so just be patient and see how it turns out.

[MattK]

Thank Google Docs for the graph. What can I say: I'm a massive geek who likes his graphs!

Thanks for the reassurance. The fly did seem less waterlogged than I would've expected. In general, can acetobacter even work in a sealed FV? Isn't it an aerobic bacterium?

[MattK]

I've been terrified of acetobacter since losing my last brew.

[gregorach]

Yeah, if it got into the fermentor, you've quite likely got an acetobacter infection... Takes a while to show though. The alcohol and low pH wont' help - those are exactly the conditions acetobacter likes (in fact it will lower the pH a lot further by metabolising the alcohol to produce acetic acid), which is why it's a beer spoilage organism in the first place. Anaerobic conditions will slow it down a lot, but probably won't eliminate it completely.

However, as Bobba says, there is a good chance that it just got into the trial jar and not the fermentor, so don't panic yet.

[Bobba]

Takes a while to show though.

Only one solution then - drink it quick just to make sure

[MattK]

An anxious couple of days for me I think

[gregorach]

This is exactly why I moved to a closed fermentor with an airlock...

The most likely explanation by far is that the fly just got into the trial jar. The chances of one managing to sneak into a closed fermentor are remote, as are the chances of you unknowingly catching a single fly in the fermentor with a pipette (they float, so you'd have to drop the pipette right over it). The chances of both happening together are astronomical.

[MattK]

That is a very good point. I didn't think of the odds of it fitting into the ~5mm pipette hole! I just got another airlock for my 2nd (currently empty) FV too. It was that one, which previously had a hole for an immersion heater, that went bad before. They're now both sealed and airlocked.

[trucker5774]

Never heard of fly sparging?

[MattK]

Never heard of fly sparging?

Hehe. That's exactly why I was unable to search to see if anyone had asked this question before! Dozen of pages on fly sparging.

[Dennis King]

What a way to die

[pas8280]

Don't know wether its an urban myth or not but there is a story that back in the 70's Boddingtons brewery employed a bloke to start work before everyone else skimming the rats out of the open fermenters !!!!!!!!!!!!!!!!!! if it is true the a single fly shouldn't be anything to worry about.

[gregorach]

I'm pretty sure that's not true, and I can tell you from personal experience that a single fly definitely is something to worry about - I've lost a batch that way before. All that cleaning and disinfection ain't for nothing, believe me.