Why are you getting infected?

[syl]

The spill tray brings them for sure!

The co2 and the sugar.

 

[Greg.L]

Homebrew beer is a beautifully safe and simple process. If you have problems, don't blame it on bad luck, a random infection getting into your brew.
If you have infections, IT'S BECAUSE YOU'RE NOT DOING IT RIGHT. All the sanitiser in the world won't help if you have something wrong in your process.

You pitch a healthy population of yeast into the wort, within 24hrs a good fermentation has started producing copious amounts of co2 and alcohol into a liquid containing a strong anti-bacterial agent. You make sure that there isn't too much air space in the fermenter, no more than 10cm, you seal it with a good lid and you leave it alone at a suitable temperature. In 2 or 3 weeks, beer! If you do it right the chance of an infection is pretty close to zero.

I realise this post will make absolutely no difference to how people on this forum brew their beer.

 

[DJ_L3ThAL]

Homebrew beer is a very safe and trouble-free process.
The thing you should never do is blame your equipment. If you have problems it is because you have done something wrong, you should face that so you can identify and fix the problem. The commonest cause of infection is too much air getting in. If you are using gladwrap to cover your fermenter and you get an infection look no further - the glad wrap is letting in too much oxygen. Most spoilage organisms need oxygen, keep a good seal on your fermenter and you keep out the oxygen, very low chance of getting an infection. If you open your fermenter often, have a large headspace, that lets in air that encourages infections. Any fermenter can be cleaned, hot water and soap will get rid of any bugs, and they wouldn't grow without air anyway.

I wish all these people throwing away fermenters would send them to me, I could put them to good use.

As for infections in cubes, leaving wort without pitching yeast is asking for trouble. You only need a few wild yeast to get in and the fermentation will start. I am only surprised it doesn't happen more often.

I think stating glad wrap lets too much air in not entirely correct, yes it is not an absolute air tight seal, but I tried multiple attempts with my bunnings drum fermenter lid and a super tight grommet/airlock which would never seem to seal up air tight, I'd get a bit of pressure on the airlock levels but even at high krausen I'd never see a single bubble through (even though I could hear the fermentation "fizz' going steady.
Since changing to glad wrap I've found it so much easier, especially when needing to lift the fermenter out of the fridge to take a sample I would not get airlock water sucked back into the fermenter from the weight of the vessel changing it's volume as I lifted it out, plus I can stave off my "expecting father syndrome" but being able to see in without removing the lid.
Each to their own of course but I would never discount glad wrap with a good rubber band as a poor quality seal!

@timmi - been a lot flying around my place recently. I haven't had any infections from the buggers but I assumed it was a cross between next door's compost and any spilled beer in my shed since I started kegging a few weeks ago. Interesting to know it's not just my place.

+1 - I am closer to you Manticle and have been noticing a truck load of them living in my conifers and a handful come into the house, maybe my conifers are the source h34r:

Homebrew beer is a beautifully safe and simple process. If you have problems, don't blame it on bad luck, a random infection getting into your brew.
If you have infections, IT'S BECAUSE YOU'RE NOT DOING IT RIGHT. All the sanitiser in the world won't help if you have something wrong in your process.

You pitch a healthy population of yeast into the wort, within 24hrs a good fermentation has started producing copious amounts of co2 and alcohol into a liquid containing a strong anti-bacterial agent. You make sure that there isn't too much air space in the fermenter, no more than 10cm, you seal it with a good lid and you leave it alone at a suitable temperature. In 2 or 3 weeks, beer! If you do it right the chance of an infection is pretty close to zero.

I realise this post will make absolutely no difference to how people on this forum brew their beer.

Couldn't agree more with this!

 

[Lecterfan]

I've had at least 10 trouble free* brews since my infection thread. The only real change I made was that I now brew in blue willow jerrys with the lid backed off slightly, two 20L and one 25L (no longer glad wrapping or using insanely top cropping yeasts...I will get back to the latter soon in the 25L willow). I also keg when the beer is ready, not 'a week or so after that because I'm lazy' haha.

Cleaning and sanitising only get you so far if your process exposes the wort to too much air, and you have 'something in the air' other than love.

I was once holier than thou about people that got infections as my cleaning and sanitising regime is fine. I'm very happy for those of you who haven't experienced it, and I hope you never have to deal with it.


edit: *other than not being totally happy with recipe, bitterness, attenuation and all the other things that picky brewers try to contend with.

 

[Greg.L]

It's not about being "holier than thou". I have no interest in blaming people, I make plenty of mistakes. The point is, if you have a problem don't just say " I need to use more sanitiser" or " I have to chuck out that fermenter". Everyone makes mistakes, when you have a problem it is your chance to analyse your process and find out what the cause was and how to fix it. Almost certainly, using more sanitiser or buying a new fermenter won't fix the problem. (unless you are using an unsuitable fermenter which is quite a common problem).

 

[syl]

It's not about being "holier than thou". I have no interest in blaming people, I make plenty of mistakes. The point is, if you have a problem don't just say " I need to use more sanitiser" or " I have to chuck out that fermenter". Everyone makes mistakes, when you have a problem it is your chance to analyse your process and find out what the cause was and how to fix it. Almost certainly, using more sanitiser or buying a new fermenter won't fix the problem. (unless you are using an unsuitable fermenter which is quite a common problem).

Exactly. Throwing out the fermenter didn't work for me. It was 9 months of leak experts and house renovations... way easier :unsure:

 

[DJ_L3ThAL]

It's hard to fix mistakes through stupidity though, but sure is invigorating/encouraging upon realisation!

I had a recent brew which the first few pours had a sweet candy-like subtle chemical taste to it, but still a decent tasting drinkable beer, just a subtle aftertaste which had me thinking there was an infection. After about 10-15 beers poured like a switch the taste was gone and it was the beer I intended it to be. After tracing my steps and thinking through my process, I had rinsed the beer lines after a sodium perc soak, so I'm attributing that taste to the unflushed residue of sodium perc.

Next time though I'll just take my kegerator to the tip h34r:

 

[stakka82]

If you have infections, IT'S BECAUSE YOU'RE NOT DOING IT RIGHT. All the sanitiser in the world won't help if you have something wrong in your process.

Bullshit.

Cleaning and sanitising only get you so far if your process exposes the wort to too much air, and you have 'something in the air' other than love.

I was once holier than thou about people that got infections as my cleaning and sanitising regime is fine. I'm very happy for those of you who haven't experienced it, and I hope you never have to deal with it.

Never truer words said.

I had 3 years without a single infection, then six months of hell. Replaced equipment. Bleached, heat treated, starsanned and sodium perc'd everything in the brewery. Still no good. Brand new gear. Infection.

Suspected it was wild yeast. Suspicions seem confirmed by Ross based on my descriptions and his experience, and from reading on descriptions of wild yeast and impact of such on wort/beer. Since then have done multiple experiments and everything points to a very, very hardy and aggressive strain of airborne wild yeast.

I now ferment off my property but do everything else on the property. Ten batches in a row not a problem, after having 6 fail in a row. They were failing when I was boiling fermenters and using new gear. Now, offsite, I just use the old non-paranoid methods of cleaning and sanitation (perc, boiling water, starsan), and everything's fine. Even with gear that had multiple infected batches brewed in it.

Sometimes it's just about luck, assuming you are taking reasonable steps towards having as sanitary brewery as possible. There's no such thing as a sterile environment.

I have a degree in biomed science and worked in pathogens laboratories for years. These are pretty sanitary places. Even so, we would often have tests fail due to cross contamination and infection, despite bleach, UV lamps, autoclaves and highly rated fumehoods/cabinets and senior phds with multiple papers under their belts.

Edit: Clarity

 

[Lecterfan]

whoa up big fella - I was talking about me haha! :icon_cheers: If I wanted to aim my comments at someone I jolly-well would haha.

edit - and I agree entirely, my case in point - it wasn't fermenters are lack of sanitiser that was the problem. I used it as an opportunity to look at my process and refine (improve?) it.

edit again - my 'whoa up' was in reference to my "holier than thou" making a repeat performance in qoute marks - I wasn't having a crack at anyone, was commenting on my attitude and no one else's.

 

[Greg.L]

Suspected it was wild yeast. Suspicions confirmed by Ross based on my descriptions and his experience. Since then have done multiple experiments and everything points to a very, very hardy and aggressive strain of airborne wild yeast.

You have no way of knowing what is happening in your ferment. I am surprised someone with a lab background could make a statement like this, based on descriptions. I would like to see a description in scientific literature of an aggressive airborne yeast. The main spoilage yeast is brett, which is never very aggressive. This sort of claim is what makes people so confused.

 

[stakka82]

No worries mate, didn't mean it to come across that way, nor as a personal attack at Greg, merely the black and whiteness of his comment.

 

[stakka82]

Didn't say I know for sure what it was, just what seems to be the likely culprit based on changing several variables.

 

[Greg.L]

The thing about aggressive airborne wild yeast ruining a brewshed doesn't really make sense. If that were true we may as well give up homebrewing now, it would be impossible under those circumstances.

One possible cause of problems is re-using yeast harvested from a brew. I know it is cheap and popular but there are inherent risks. When we pitch a yeast we shouldn't expect to have a pure culture growing in our beer. Other nasties will sometimes get in there no matter how good your sanitisation, but saccharomyces yeasts are so good they outcompete everything else. There is a brief window in the first few hours when the nasties can grow, if you re-use the yeast you are multiplying the window and the nasties can build up their populations to levels that cause problems. It is normally fine but if you do it and you get an infection, that may be the cause.

The problem with gladwrap is not just the seal, but oxygen can pass straight through plastic film, even with a pressure of co2 inside (see dalton's law). It is definitely an inferior way to seal your fermenter. You may get away with it but that doesn't mean you should do it.

 

[JDW81]

Bullshit.

I'll have to disagree with you on your disagreement with Greg.

While I will conceded that infections can happen sporadically, the overwhelming majority of infections are due to a problem in someones process somewhere along the production line. The most common one I see is people not washing their fermenters properly prior to sanitising, and as per Greg above if your process is flawed then all the sanitiser in the world is not going to stop unwanted organisms infecting your brew. You might get away with it most of the time, but an infection is inevitable at some stage. It is impossible to sanitise a fermenter if it isn't clean in the first place.

 

[mje1980]

The thing about aggressive airborne wild yeast ruining a brewshed doesn't really make sense. If that were true we may as well give up homebrewing now, it would be impossible under those circumstances.

One possible cause of problems is re-using yeast harvested from a brew. I know it is cheap and popular but there are inherent risks. When we pitch a yeast we shouldn't expect to have a pure culture growing in our beer. Other nasties will sometimes get in there no matter how good your sanitisation, but saccharomyces yeasts are so good they outcompete everything else. There is a brief window in the first few hours when the nasties can grow, if you re-use the yeast you are multiplying the window and the nasties can build up their populations to levels that cause problems. It is normally fine but if you do it and you get an infection, that may be the cause.

The problem with gladwrap is not just the seal, but oxygen can pass straight through plastic film, even with a pressure of co2 inside (see dalton's law). It is definitely an inferior way to seal your fermenter. You may get away with it but that doesn't mean you should do it.

You are aware that a huge number of breweries in Europe use open fermenters right?. They don't worry too much about sealing their fermenting vessels or oxygen getting in the way?

 

[stakka82]

My problem happened with both sealed and glad wrapped fermenters.

It also happned with a brand new fermenter, washing is not the issue.

It happened with repitched, and fresh liquid and dry yeast.

It has since stopped happening when moving to a different environment but keeping all other variables constant.

but saccharomyces yeasts are so good they outcompete everything else.

Have a google of killer toxin viruses in yeast, and the transmission of viruses between wild/wild and wild/domestic strains. Yeast populations swap genes all the time due to reproduction or pathogens. Add in a few genes for increased dispersal via air currents and it's theoretically possible. Not saying this is the culprit but it's certainly a possibility.

http://en.wikipedia.org/wiki/Killer_yeast

http://rna.genomics.purdue.edu/@api/deki/files/1186/%3DYeast_killer_toxins%25252c_lethality_and_protection.pdf

http://www.babblebelt.com/newboard/thread.html?tid=1108752780&th=1275037001


"-All ale yeast are 'susceptible.' Most wine yeasts are killer. That means that wine yeast added to a fermenting ale will kill off the ale yeast already present."

The abstract in this one is especially interesting

http://onlinelibrary.wiley.com/doi/10.1002/jctb.5020260208/abstract

 

[Greg.L]

You are aware that a huge number of breweries in Europe use open fermenters right?. They don't worry too much about sealing their fermenting vessels or oxygen getting in the way?

This is another trap for homebrewers, the "traditional open fermenter" fallacy. Go to any microbrewery in Australia, you will see the fermenters are full, closed up and well sealed. If they aren't, they will be in a while after their first few infections. KEEP THE AIR OUT. Four simple words that will prevent a whole lot of heartbreak.

A lot of infection photos I have seen have half-full fermenters. This is another obvious problem. A big airspace will make it much easier for oxygen to get in, if you want to do a smaller brew you need a smaller fermenter.

 

[DJ_L3ThAL]

The problem with gladwrap is not just the seal, but oxygen can pass straight through plastic film, even with a pressure of co2 inside (see dalton's law). It is definitely an inferior way to seal your fermenter. You may get away with it but that doesn't mean you should do it.

This is another trap for homebrewers, the "traditional open fermenter" fallacy. Go to any microbrewery in Australia, you will see the fermenters are full, closed up and well sealed. If they aren't, they will be in a while after their first few infections. KEEP THE AIR OUT. Four simple words that will prevent a whole lot of heartbreak.

A lot of infection photos I have seen have half-full fermenters. This is another obvious problem. A big airspace will make it much easier for oxygen to get in, if you want to do a smaller brew you need a smaller fermenter.

Fair enough Dalton's law states partial gas pressures allow such a transfer at the interface point (ie. glad wrap barrier), but surely with a bulk volume above the wort of more dense CO2 you will have enough of a barrier that the air will not travel downward through the more dense CO2 to come into contact with the wort, it defies physics/gravity? This also would suggest your suggestion of decreasing head space in a fermenter does not help as this would reduce the volume of CO2 protection above the wort, does it not?

 

[Greg.L]

Fair enough Dalton's law states partial gas pressures allow such a transfer at the interface point (ie. glad wrap barrier), but surely with a bulk volume above the wort of more dense CO2 you will have enough of a barrier that the air will not travel downward through the more dense CO2 to come into contact with the wort, it defies physics/gravity? This also would suggest your suggestion of decreasing head space in a fermenter does not help as this would reduce the volume of CO2 protection above the wort, does it not?

Sorry but you don't really understand partial pressures. Two different gases, such as co2 and o2 can mix fully without increasing the volume. Because there is no o2 inside the fermenter and lots outside, there is a strong concentration gradient drawing the o2 into the fermenter. It is very counter-intuitive and difficult to appreciate, but a blanket of co2 doesn't stop the o2. Once the oxygen gets in, aerobic spoilage bugs like acetobacter and film yeasts can go to town on the surface of the beer. If you see stuff growing on the surface then that is usually an indication that oxygen is present.

 

[DJ_L3ThAL]

Sorry but you don't really understand partial pressures. Two different gases, such as co2 and o2 can mix fully without increasing the volume. Because there is no o2 inside the fermenter and lots outside, there is a strong concentration gradient drawing the o2 into the fermenter. It is very counter-intuitive and difficult to appreciate, but a blanket of co2 doesn't stop the o2. Once the oxygen gets in, aerobic spoilage bugs like acetobacter and film yeasts can go to town on the surface of the beer. If you see stuff growing on the surface then that is usually an indication that oxygen is present.

It's a very interesting concept (albeit the wiki description says it is not followed by real gases as strictly as the definition), but it does make me wonder if practically, the O2 passing across the glad wrap would be filtered of airborne bugs somewhat? Because due to the partial pressure theory, by the end of a standard 2 week fermentation process the head space of the fermenter is a complete mix of CO2 and O2, surely most people using glad wrap lids would be finding oxidation occurs on the surface at the very least?

There is also the practicality argument for those needing to lift the fermenter to take a sample, in order to stop airlock water being sucked into the beer I'd need to remove the airlock, opening a hole allowing air travel far more easily than a glad wrap lid true?