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Tragedy - Bacteria!

I opened up my fermenter to add nutmeg (soaked in vodka) to my pumpkin ale, and found this:

It’s the first time I’ve ever had an infected batch and the first time I’ve ever used the conical.

What do I do? It’s 15 gallons of what is normally a phenomenal beer. Should I try to drink it anyway? It doesn’t smell bad, it just has that disgusting spider film on top. Can I skim it off?

Also, what should I do to rehab my equipment? This is a a plastic conical, so some edges are a little rough, but there aren’t any scratches as far as I could tell. And if I do try to drink it, I assume it’ll infect my keg, too? How do I clean that?

I’m so bummed right now.

EDIT: I just tasted it, and it tastes fine (not as sweet as I would have expected, but definitely not sour).

What should I do? Get it out of there immediately, or let it do its thing? It’s not supposed to be done for another week.

That looks like Acetobacter. If it is, the good news is that it’s anaerobic (EDIT: aerobic). If you can purge another vessel with CO2, then gently transfer the majority of the beer out from under the pellicle, you might be able to limit the damage. That assumes you’re kegging, though. I wouldn’t risk bottling anything I knew to be contaminated.

As far as cleaning the conical, your normal cleaning/sanitizing regimen should be sufficient. Does it have a CIP ball or do you have to clean it by hand? The only difference is that if you can’t run a loop on it you’ll have to use a lot more of the chemicals in order to immerse the entire surface. Either way, I’d remove any particulates, then do 30-60 min of contact time with an alkaline cleanser (PBW, CMC, OxiClean, One Step, etc.) at 160-180°F, followed by a thorough hot water rinse and 10 min of contact time with a no-rinse sanitizer. My preference when dealing with an acid-producing contaminant would be to use an iodophor, since the microbes will presumably display some tolerance to low pH.

Thank you so much for your reassurance!

I have to clean it by hand. I built it out of random parts I ordered through the internet.

I only keg. I can just put it in my keg, and then clean the keg like normal when it’s done? What about the taps / beer line, sanke, etc?

Why is it good that it’s anaerobic? Doesn’t that mean it’ll continue to thrive in a keg, topped off with CO2?

Should I just keg it now? I have a second conical that’s the same size, but getting the beer into it involves siphoning it into a bucket, then pouring the bucket into the top of the second fermenter. My other option is to siphon the beer out of the fermenter and into several carboys. I like that idea, because then I can keep an eye on them for the last week while the beer finishes up, but the only reason it has another week is because I like to let it sit and mellow, and let the spices meld.


If you can clean the line, tap, coupler, etc. very thoroughly with caustic, you’ll probably be OK. Otherwise, you might want to consider dedicating a new line and plastic picnic tap to this batch, then discarding them when you’re finished with it.

Yeah, that was a total brainfart on my part. Acetobacter is aerobic.

As long as you can purge the receiving vessel(s), either of those should work. I’d suggest kegging now, or waiting a week and then kegging, so that you only have to do one transfer instead of two. Whatever you do, just try to minimize exposure to the air.

You could also try spiking your brew with sugar to cause renewed fermentation that would flush the vessel with CO2 and kill of most if not all of Acetobacter. I hate when that happens, but the good news is that the damage does not occur very quickly. Kegging is indeed a good option.
I had this happen recently with my braggot (the suckers must have hitched a ride on the honey). I kegged it about a week after I saw it appear and it actually came out better than I expected lol.

Okay, the only way I can keg 15 gallons of this stuff is to use a commercial keg, which means a commercial sanke, so I may as well just take my chances with cleaning afterwards.

I’m going to use a racking cane and hose to siphon from the conical to the keg, then I’ll soak it all in OxyClean for a day, then I’ll go pick up some Iodophor (Normally, that’s what I use, but I let the guy sell me on StarSan acid rinse. Even if this infection has nothing to do with the switch, StarSan is way too foamy, and I’ll never use it again.), and let the Iodophor solution sit for a day.

As for cleaning the sanke / taps / lines, normally I run OxyClean or BLC through the lines, then pump an Iodophor solution through and let it sit for a day. Then I flush the lines, take the tap faucet apart and let that soak in a BLC solution, then in an Iodophor solution. I’ll let the sanke sit in the Iodophor solution, too, this time (normally, I just rinse it in the Iodophor).

As for the keg, it’ll get the regular OxyClean for a day, Iodophor for a day treatment.

Sound like a good plan?

Normally, I drain the OxyClean solution from the fermenter into the keg, then pump that through the lines, and do the same with the Iodophor solution. Is that okay to do this time, or am I risking transferring the contamination around?

Thanks for all your help guys!

Well, I filled a keg with CO2 yesterday, transferred the beer into it (using a plain ol’ racking cane and tubing, since I hadn’t installed the racking port on the side of the fermenter yet), and topped it off again with CO2, just to be sure. It’s carbonating as I type.

Since there wasn’t any sign of infection when I checked on it a week ago, I’m pretty sure this was a recent development; the beer tastes just fine – no sour or vinegar notes, as far as I could tell.

I left about a gallon of beer in the fermenter because I was so nervous about accidentally sucking up some of that scum. However, when I opened it up to transfer the beer, it looked like the pellicle had broken up some; not sure if that’s a good sign or if it means it just sunk to the bottom, to get sucked up with the beer. I did get a few gloopy globs when I let the racking cane get too close to the yeast cake, but I’m assuming that was just yeast.

In retrospect, I think the problem was a combination of four things:
(1) When I poured the wort into the fermenter, I slopped it all over the place. I cleaned it up, but there wasn’t really an easy way to clean in the threads for the lid with the wort already in the fermenter.
(2) There are always a few fruit flies buzzing around in our house. Comes from growing peppers indoors.
(3) The lid on my plastic conical isn’t even close to airtight. I figured this wouldn’t be a problem, since the fermentation process would create a nice blanket of CO2 to protect my beer, but…
(4) I kept opening up the lid once a week to check on it / add spices. Normally, I just leave it alone, but for some reason, I got jittery.

On my to-do list:
(1) Install a racking port, and improve the seal of the lid
(2) Chuck the StarSan acid sanitizer (the cap for the bottle just broke today, anyhow). Go back to Iodophor.
(3) Be more careful putting the wort into the fermenter next time (maybe use a bottling bucket?)
(4) RDWHAHB (Hopefully, there’s no acetobacter scum floating in it)

quote=“NinjaBob” There are always a few fruit flies buzzing around in our house. Comes from growing peppers indoors.
(3) The lid on my plastic conical isn’t even close to airtight.[/quote]
I don’t think you need to look any further. That combination is an accident waiting to happen.

I wouldn’t blame this on star-san and actually having a combo of santizers (obviously NOT at the same time!) Is a little extra defense against any critters that may have an immunity to one or the other.

Yeah, I agree. My comments on StarSan were more a reflection of my personal preference for Iodophor and my assumption that an acid sanitizer probably won’t be as effective at getting rid of an acetobacter infection as Iodophor would.

I agree with Sean that you might want to use Iodophor, but don’t write off Star San and as has been said in finitum, “Don’t fear the foam”.


I don’t fear the foam, but if I don’t rinse it out, I can taste it in my beer (or at least, I think I can, which is the same thing in the end).

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