Author Topic: Recurrent infection in stainless steel fermenter  (Read 681 times)

Offline The Alchemist Brew

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Re: Recurrent infection in stainless steel fermenter
« Reply #15 on: September 07, 2020, 04:00:00 PM »
Before I filled the fermenter with percarbonate I used to fill it with iodophor, iodine to 25 ppm with citric acid in water. It didn't work. I still had infections. I know for sure that it doesn't kill bacterial spores.
With the percarbonate I did manage to brew without infections. Maybe one hour is not enough. Maybe overnight will do the trick. I did read that some guy from New Zealand or Australia always uses percarbonate overnight and never has infections. That's why I am willing to give it a try. And the stuff is cheap.

If it doesn't work, then I will use percarbonate, then star san. This should kill the bacteria because the first is alkaline, the second is acidic. Both are disinfectants.
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Offline narvin

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Re: Recurrent infection in stainless steel fermenter
« Reply #16 on: September 07, 2020, 04:36:50 PM »
Before I filled the fermenter with percarbonate I used to fill it with iodophor, iodine to 25 ppm with citric acid in water. It didn't work. I still had infections. I know for sure that it doesn't kill bacterial spores.
With the percarbonate I did manage to brew without infections. Maybe one hour is not enough. Maybe overnight will do the trick. I did read that some guy from New Zealand or Australia always uses percarbonate overnight and never has infections. That's why I am willing to give it a try. And the stuff is cheap.


You should use both.  Sanitizers are rapidly inactivated by organic solids.  As hopfenundmalz said, clean, then sanitize.

Online BrewBama

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Recurrent infection in stainless steel fermenter
« Reply #17 on: September 08, 2020, 02:03:36 PM »
... I did read that some guy from New Zealand or Australia always uses percarbonate overnight and never has infections. That's why I am willing to give it a try. ...

Correlation does not equal causation. Just because he told you that he never had an infection may or may not be due to his process.  Quite frankly, a brewer that says they never had an infection is suspect IMO.

For what it’s worth, I’ve had an infection using Star San but never with Iodophors.  ...but I blame it on the cleaner (both the product and the laborer).

Always mix BTF Iodophor into cool or lukewarm water.  The hotter the water, the faster the Iodine will gas into the atmosphere.

Mix rate:
1/2 ounce (14.7 ml) concentrate per 5 gallons of water;
1/4 ounce (7.39 ml) concentrate per 2.5 gallons of water;
1 tsp (4.92 ml) per 1.5 gallons of water.

Things that will degrade the solution:

-Residual alkaline detergents.  The Iodine complex and the Iodophor concentrate are acidic solutions.  Mixing into any water that has residual alkaline detergent will neutralize the solution.

-Excessive agitation or shaking

-UV light, so leave your solution in a dark place

Using iodophors with citric acid is not the normal usage regime. It not killing bacteria could be because you misused it and have nothing to do with effectiveness.


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« Last Edit: September 08, 2020, 02:10:29 PM by BrewBama »
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Offline majorvices

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Re: Recurrent infection in stainless steel fermenter
« Reply #18 on: September 08, 2020, 02:32:44 PM »
I have only used star san (as a homebrewer) for the last ... I dunno at least 15 years, and have never had a (homebrew) infection during that period. I am a meticulous cleaner which is far more important than sanitizer anyway. You can think of sanitizer as just a "precaution". Totally agree with the "clean, then sanitize" statements.

For me, oxi-clean soak, light scrubbing, good rinse and star san works every time. Anything difficult to sanitize gets either boiled or at least "flash boiled".

I have had infections when the fermenter wasn't sealed properly and air has made it's way in (such as a dry airlock).

Obviously, being a commercial brewer, I have a different approach completely for professional applications. But sanitation issues on the home brew scale are usually due to careless cleaning or overlooking something vital (like a ball valve). It is so damn easy to keep everything clean and sanitized that if a homebrewer follows close attention to detail it simply shouldn't ever be a real problem - even with simple star san.

Online BrewBama

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Recurrent infection in stainless steel fermenter
« Reply #19 on: September 08, 2020, 03:41:35 PM »
I knew as soon as I typed that someone would say they’ve never had an infection.


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Offline majorvices

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Re: Recurrent infection in stainless steel fermenter
« Reply #20 on: September 08, 2020, 05:22:59 PM »
I knew as soon as I typed that someone would say they’ve never had an infection.


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I've dumped more beer in one day due to infection than everyone here on this forum combined most likely.  :o What I meant was I never had an homebrew infection directly related to the sanitizer I was using. In this case Star San.

I've unfortunately had my share of infections believe me.
« Last Edit: September 08, 2020, 06:37:04 PM by majorvices »

Offline The Alchemist Brew

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Re: Recurrent infection in stainless steel fermenter
« Reply #21 on: September 08, 2020, 06:43:39 PM »
First of all: what infection is it?
I've read this: https://www.wearecellix.com/post/microbes-that-ruin-a-perfect-pint
and yesterday I opened an old bottle with an infected homebrew. A lot of diacetyl and off smell, not vinegar, but like vomit. So I think it's Pediococcus or Clostridium. I don't know if these make spores.
If they make spores, that's the cause: I used iodophor which didn't kill the spores. And where did they hide? In the ball valves. That's the only place I couldn't get to. (I used citric acid in iodophor in cold water and left it for an hour because I read in wikipedia that the iodophor, in order for the iodine to be active, needs a pH between 2 and 5).

So I know the cause and I know the site of infection. Somebody used a heating element to boild the water inside the steel fermenter. I think that's a good idea. I might try it. I don't know if the silicone gaskets will hold, though.

The reason I think percarbonate in the full fermenter overnight would be a good idea is this: if I don't raise the concentration of the disinfectant solution I can prolong the time the disinfectant stays in contact with the surface. I have been using it for a contact time of one hour, maybe 12 hours will do the trick.

And why I think the ball valves are the cause is this: when the ball valve is closed, there is no contact between the wort and the outside, it is hermetically sealed. But when I take a gravity reading, I open the ball valve, beer flows through the open valve and when I close it, wort gets trapped inside that valve which means infection. And when I open it again, that trapped infected wort will ruin my whole 5 gallons of beer.

What I am going to do from now on is this: I will brew my next batch of beer and all the beers subsequently in the same manner.
I will fill my fermenter with sanitiser and leave it overnight fully closed.
I will weigh and mill my grains one night before I will brew.
On brew day, I will take only one gravity reading, the preboil gravity and that's it.
Then I will ferment my beer the same way I use to, but without ever taking a gravity reading. The only gravity reading I will take will be on bottling day or not at all. I ferment at very high temperatures, so I never had a batch that didn't fully attenuate.
The airlock has been replaced with a blowoff tube in a jar of vodka. This lets me see how much suckback I have.
And I think I'm good.
« Last Edit: September 08, 2020, 06:46:09 PM by The Alchemist Brew »
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Offline reverseapachemaster

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Re: Recurrent infection in stainless steel fermenter
« Reply #22 on: September 09, 2020, 02:56:02 AM »
I also suspect your infection woes come from milling next to the fermentation vessel. In addition to taking steps to clean and sanitize the ball valves and milling the night before I also wonder whether the room itself has become part of the problem. If you've been milling in there then there is likely grain dust on the walls, ceiling and floor. When you wander in there to pour in the wort or sample from the ball valve you are probably disturbing the dust and getting it floating around in the room where it lands in the wort and around the ball valve. Milling the night before would help how much active dust is floating around on the brew day but will still add to the grain dust on the surfaces in the room. Is there a way for you to mill somewhere else entirely?
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Offline skyler

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Re: Recurrent infection in stainless steel fermenter
« Reply #23 on: September 11, 2020, 06:37:57 PM »
There are two issues here that need to be addressed: (1) milling next to your open fermenter is asking for trouble and (2) sodium percarbonate is not a great sanitizer -- in fact I don't consider it to be a sanitizer at all, merely a cleaner. And I rinse it with tap water -- water from your kitchen tap could very well be a source of contamination.

For (1), if you can't mill elsewhere, at least close and seal your fermenter before milling.

For (2), buy some StarSan/ChemSan or at least an iodine sanitizer. You don't need much. Just get the right concentration in a spray bottle and spray everything AFTER you have rinsed out your cleaner. Make sure to sanitize that ball valve, too.

Offline Saccharomyces

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Re: Recurrent infection in stainless steel fermenter
« Reply #24 on: September 12, 2020, 03:52:27 PM »
I suspect that you are pitching the infection with the culture. Bacteria infections of that magnitude that appear that quickly are almost always pitched with the yeast culture. The way you are handling your dry yeast cultures is no, just no. You should not rehydrate your culture until your are ready to pitch.  Dry yeast needs a carbon source after it has been rehydrated. Given your experiences, I would suggest wiping the outside of yeast packet with a cotton ball soaked with alcohol and do the same thing with the scissors you use to cut the packet open before cutting it open and pitching its contents. Bacteria rarely gets sucked back in through an airlock, especially one that contained alcohol. I almost never fill an airlock. Wild microflora rides on house dust. It does not crawl into one’s fermentation vessel. That means not pitching in a drafty, dusty room.  If you would like a greater understanding of the topic, read my article entitled “Yeast Cultures are Like Nuclear Weapons” on the Experimental Brewing website (see https://www.experimentalbrew.com/blogs/saccharomyces/yeast-cultures-are-nuclear-weapons)
« Last Edit: September 13, 2020, 08:27:57 PM by Saccharomyces »

Offline The Alchemist Brew

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Re: Recurrent infection in stainless steel fermenter
« Reply #25 on: September 15, 2020, 05:39:09 PM »
I tried out my ideas.
Didn't work. Milled grain got in the fermenter and I got an infection, it smelled sour.
I tried a koelsch, pilsner malt, tettnanger and K-97 yeast. After I drained the percarbonate solution I saw on the sides of the fermenter a lot of residue and it looked like milled grain. So that's the cause. I will try to mill in another room.
Percarbonate is an excellent sanitizer. It is an oxidant but far less so than chlorine (bleach).
I will try again and see the outcome. I have a feeling that if I mill in another room, the problem will be solved.
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Offline The Alchemist Brew

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Re: Recurrent infection in stainless steel fermenter
« Reply #26 on: September 24, 2020, 08:38:31 AM »
I think the cause of my infection is that I make beginner's mistakes.
The last batch got infected as well.
The ale was a SMASH, Weyermann pilsner malt, tettnanger hops and US-05 yeast.
Cleaned the fermenter without taking out the spigot and thermowell. I think that this was the biggest mistake. And when I fermented, I opened the top of the fermenter to smell the action. On day two it got infected.
Right now I am fermenting one of my beers. It's on day two of fermentation. I followed your advice, and thank you all for all the great pieces of advice you gave me.
First of all I cleaned the fermenter with dish detergent. Then I pulled out the spigot and cleaned it. Pulled out the thermowell and cleaned it. It was rusted, so this is an unfortunate surprise. I soaked it in 10% citric acid.
Reassembled the fermenter. Put boiling water in it, rinsed the ball valves with the boiling water.
On brew day, milled the grains far from the closed fermenter.
Put percarbonate in fermenter, left it for an hour. Drained it through the ball valves to clean them.
Rinsed with boiled and cooled, sterile, water.
Sprayed the hell out of the inside of the fermenter and the cooling lid coil with iodophor solution made from 10% citric acid. I have read that this citric acid concentration is great for passivation of stainless steel, dissolves rust and has some antibacterial properties.
Then I poured the cooled wort in.
The yeast was resuspended in boiled and cooled water. I make it the same way I make my starters. I don't think that the problem is here. I am following what I have read in the book Yeast: The Practical Guide to Beer Fermentation by Chris White and Jamil Zainasheff.
I am never opening the fermenter or the ball valves until the beer is finished.
So I think I am good.

 
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Offline ynotbrusum

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Re: Recurrent infection in stainless steel fermenter
« Reply #27 on: September 24, 2020, 11:13:42 AM »
You should be good to go.  If you want to take it a step further, consider a closed loop transfer for the final step.  That should close out contamination vectors through to packaging.
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Offline reverseapachemaster

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Re: Recurrent infection in stainless steel fermenter
« Reply #28 on: September 25, 2020, 03:32:30 AM »
It's certainly possible you are infecting the beer when you open it but just like the yeast you pitch it takes time for unwelcome guests to grow to a volume that they are producing noticeable effects on the beer.

Keep inspecting and cleaning your equipment and space. If your beers are getting infected from something in the fermentation space and not the yeast you are pitching then it is possible the contaminant has taken up residence in the room itself from all the milling. Personally I would give the entire room a good vacuuming including walls and ceiling. If the walls and ceiling can be wet cleaned I would consider wiping them down with something antimicrobial. I would eliminate as many environmental factors as possible. Cleaning your fermentation space has no downside for your beer.
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