Author Topic: Infection  (Read 3250 times)

Offline AmandaK

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Re: Infection
« Reply #15 on: June 07, 2013, 06:30:14 AM »
The beer had a very sour rancid flavor that overwhelms all other flavors.  The beer was also cloudy with a fine white haze.  My uninfected beer tends to be very clear.  Also this flavor increases with time so after about a week and a half the beer is so bad it is impossible to drink more than a couple of sips.

Since I don't have a microscope I am guessing this is acetobacter.  Am I incorrect in this guess?

I thought of the bung thung also so I threw them out and ordered new ones.

Hmm... take a look at these off-flavor flash cards and see if you can pin it to one or two of those. http://www.beerjudgeschool.com/uploads/Beer_Characteristics_Flash_Cards.pdf From your description, it sounds exactly like a bacterial infection (rancid, sour, cloudy & exponential growth are all signs of bacterial infection) - most likely acetobacter.

Correct me if I'm wrong, but here's what I see:
- Your brewing process seems sanitary due to the presence of uninfected beers.
- You're not sampling or even opening some of the infected beers.
- Glass carboys should be clean.

I don't know if the issue is just the freezer. Is there some sort of plastic equipment that you may just happen you use on these infected batches? Airlocks? Tubing? Bungs? Buckets? Are they sour in the fermenter or after bottling? If in the fermenter, that narrows it down. If after bottling, that opens up all of your bottling equipment to suspicion.

FWIW, I had a small phenolic infection in my brewery about 8 months ago. I did not chance wasting any more beer and threw out all of my plastic stuff and started again.
Amanda Kertz
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Offline kylekohlmorgen

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Re: Infection
« Reply #16 on: June 07, 2013, 07:23:26 AM »
FWIW, I had a small phenolic infection in my brewery about 8 months ago. I did not chance wasting any more beer and threw out all of my plastic stuff and started again.

...usually cheaper than a 5-gallon extract batch that might otherwise go down the drain.
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Offline AmandaK

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Re: Infection
« Reply #17 on: June 07, 2013, 08:26:39 AM »
FWIW, I had a small phenolic infection in my brewery about 8 months ago. I did not chance wasting any more beer and threw out all of my plastic stuff and started again.

...usually cheaper than a 5-gallon extract batch that might otherwise go down the drain.

Exactly.
Amanda Kertz
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Offline t-bone

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Re: Infection
« Reply #18 on: June 07, 2013, 08:22:41 PM »
Those are some very good points AmandaK.

The beer is sours during the fermentation.  All in all I have had 7 sour batches out of about seventy batches.

All my hoses are high temp silicon and all the fittings are stainless camlocks.  The wort goes from the boil kettle to a march pump then a blichmann ferminator.  After that straight to the glass carboy.  I add 60 seconds of Oxygen at 1 cfm thru a stainless 5 micron air stone.  After that I pitch the yeast, cap the car boy with a bung, and agitate it for 60 seconds.  I then place the air lock and fill it with everclear and put it in the chest freezer.

I identified some discoloration in my carboy bungs.  Looked like a mold discoloration.  I am leaning toward the carboy bungs being the case of the infection.


Offline a witty man

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Infection
« Reply #19 on: June 08, 2013, 08:21:57 AM »
The air stone / aeration setup could be a source as well. Those things are really difficult to clean without boiling.
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Offline AmandaK

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Re: Infection
« Reply #20 on: June 09, 2013, 06:39:56 PM »
The beer is sours during the fermentation.  All in all I have had 7 sour batches out of about seventy batches.

All my hoses are high temp silicon and all the fittings are stainless camlocks.  The wort goes from the boil kettle to a march pump then a blichmann ferminator.  After that straight to the glass carboy.  I add 60 seconds of Oxygen at 1 cfm thru a stainless 5 micron air stone.  After that I pitch the yeast, cap the car boy with a bung, and agitate it for 60 seconds.  I then place the air lock and fill it with everclear and put it in the chest freezer.

I identified some discoloration in my carboy bungs.  Looked like a mold discoloration.  I am leaning toward the carboy bungs being the case of the infection.

So the ones that aren't infected, what changes to the process are you making? Or is it as simple as using a moldy bung on the suspect batches?

Either way, please report back when you get a new beer through the system - we all love closure!  :)
Amanda Kertz
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Offline t-bone

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Re: Infection
« Reply #21 on: June 21, 2013, 10:05:55 PM »
Closure!!!

This is for AmandaK. 

I brewed three batches of beer (Irish red, Blonde, and California Common) using the exact methodology I described earlier; but, with new bungs and airlocks.  AND NO INFECTION.  Never underestimate Occam's razor.

Thanks to everyone who provided input. 

pat

Offline AmandaK

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Re: Infection
« Reply #22 on: June 24, 2013, 05:12:07 AM »
Closure!!!

This is for AmandaK. 

I brewed three batches of beer (Irish red, Blonde, and California Common) using the exact methodology I described earlier; but, with new bungs and airlocks.  AND NO INFECTION.  Never underestimate Occam's razor.


Excellent to hear!  ;D
Amanda Kertz
Kansas City Bier Meister
BJCP National

Redbird Brewhouse - Current Project: Full Basement Bar Build