Botulism

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elzzib

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Does anyone know the risk of botulism as far as homebrew goes? Considering the fact that homebrewing essentially creates an anaerobic environment rich in nutrients for microorganisms, it seems like botulism would be a concern. Many other infections can occur in homebrew, so I see no reason why a botulism infection couldn't occur. This, coupled with the fact that botulism toxin is odorless and tasteless is somewhat unnerving. Are there any biologists on this forum who could give a final word on if homebrew is a viable environment for botulism?
 
From what I head, botulism can grow in wort as its pH is high enough, but it won't grow in beer since the pH of beer is low enough to inhibit growth. Beer is safe, wort needs to be pressure canned or frozen if it is stored for a longer time.

Kai
 
The bacterial spore Clostridium botulinum is found in soil and subsequently can make it to into anything that grows in dirt. Of course this does include grain. The spores themselves are not what causes botulism. The toxin that causes botulism is a byproduct of their reproduction which only occurs in anaerobic, non-acidic (above ph 4.6) environments.

The spores themselves are killed by boiling (some robust strains can survive an hour or more, but it's not common). Once dead, of course they can't reproduce so they can't produce the toxin which causes botulism in your beer. Additionally, the average ph of fermented beer is between 4.0 and 4.4, which is acidic enough to keep any spores that did survive the boil from reproducing.

Simply put, don't worry about it. :mug:

FDA Page on Botulism
http://www.cfsan.fda.gov/~mow/chap2.html
 
So , I used papazans recipe of using unfermented wort instead of corn sugar to bottle my latest batch of beer. He said you could just put it in the refrigerator, in a sealed container, and it would be okay. When I opened it yesterday to bottle, it smelled kinda funny. I couldnt tell if it was just the smell of unfermented wort, so I used it anyway. But now reading this post it makes me think something (i.e. botulism) might have happened to the wort.

Any suggestions?
 
you won't smell botulism.

if you put the wort in a sanitized vessel, it'll be fine for at least a week or two in the fridge.
 
The botulin toxin producing bacteria is inhibited at a pH < 5.5. Beer is typically about about pH=4.0-4.5. Since pH is logarithmic, that means beer is over ten times too acidic for C.botulinum to grow.

And that isn't even considering the fact that most bacteria can't grow in an environment with even a small amount of ethanol (grain alcohol).

If you are storing wort in the fridge (~33ºF), the bug can't grow there either. It is too cold.

People have been brewing beer for a really long time, in conditions that were far dirtier than the typical kitchen today. As sirsloop put it, someone would have died already.

http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=2178781&dopt=AbstractPlus

http://www.foodprotect.org/doc/III-16b Cbotfactsheet.pdf
 
glennduggin said:
Any suggestions?

I always keep left over unfermented wort for priming and making starters. Though I have read that it is safe in the fridge for a while I don't fully trust this and freeze or pressure can all wort I'm keeping. It might be fine in the fridge for a week or so, but I don't want to be in a rush and bottling time is generally 3-5 weeks after brewing.

By freezing and subsequent re-boiling, I also don't have to follow sanitary procedures when collecting and storing the wort. This makes the process easier.

Kai
 
Ahh well this is a relief. One more question, though. It sounds like beer is pretty safe when if comes to botulism poisoning, but what about wine and cider? What are the pHs of those?
 
My understanding is that there are no known pathogens that can survive the brewing process. that goes for beer, wine, cider, mead...ect ect ect...

Something to think about. Back in the day, the Beer/grog brewed was safer to drink then the water.
 
Zzyzx said:
My understanding is that there are no known pathogens that can survive the brewing process. that goes for beer, wine, cider, mead...ect ect ect...

Ummm ... if that were true, we wouldn't have beer, wine, mead or cider much less infected batches of beer/wine or whatever.
 
srm775 said:
Ummm ... if that were true, we wouldn't have beer, wine, mead or cider much less infected batches of beer/wine or whatever.
Correct me if I'm wrong, but by pathogen he meant an organism that could cause disease in humans. The organisms used to ferment beer, wine, mead, etc aren't capable of causing disease (in humans), according to Zzyzx.
You know, you just don't expect to see a thread on Botulism
haha yeah maybe it wasn't very smart to name the thread that. I think there's approximately a 50% chance I'm going to get my house raided within the next week, and accused to trying to grow botulism in my fermenter. I'm a terrorist fo' sho'
 
gruntingfrog said:
The spores themselves are killed by boiling (some robust strains can survive an hour or more, but it's not common).

I don't think that is entirely true. The spores can survive up to and over 2 hrs in 212 °F and research has shown that they can survive higher temperatures than offered by boiling. This is the reason why home canning of low acid foods must be done under pressure. I have been in homes where people can their beans by 'boiling them long enough', scares the crap outta me. :D At any rate, as mentioned the real saving grace is the pH drop in beer.
 
srm775 said:
Ummm ... if that were true, we wouldn't have beer, wine, mead or cider much less infected batches of beer/wine or whatever.
No known human pathogens can survive the brewing process. Ofcourse there are a number of bugs that can infect wort or beer. An infected beer may taste horrible but it won't kill you.

Craig
 
zoebisch01 said:
I don't think that is entirely true. The spores can survive up to and over 2 hrs in 212 °F and research has shown that they can survive higher temperatures than offered by boiling. This is the reason why home canning of low acid foods must be done under pressure. I have been in homes where people can their beans by 'boiling them long enough', scares the crap outta me. :D At any rate, as mentioned the real saving grace is the pH drop in beer.


Yes the pH is THE factor. The spores will survive boiling temps but a spore must have an ideal condition to start to reproduce. The pH of beer is no where near ideal
 
and what about mead??
is mead's PH low enough to avoid botulism???

this is my first attempt to brew mead and some people scared the cheat out of me saying that there could be stuff like that on a omebrew mead.
 
I think I have a tiny bit of botulism in every one of my beers.
Not enough to make me sick if I drink a bit.

It's just that when I get to 10 or more it starts to make me ill.
 
I think I have a tiny bit of botulism in every one of my beers.
Not enough to make me sick if I drink a bit.

It's just that when I get to 10 or more it starts to make me ill.

Are you sure it's not simply because you drank 10 beers in a row:D

Seriously though, last year when I was googling for info on pathogens in beer, I came across the microbiologist/homebrewer railing against a fellow brewer (it was on one of those "color coded" brewboards where they are a little less friendly than we are.) I just cut and pasted it and stuck it in a file...here it is.

Can you get a PATHOGEN from beer. No. NO *NO* Did I make that clear? You have a ZERO chance of pathogens in beer, wine, distilled beverages. PERIOD!

Pathogens are described as organisms that are harmful and potentially life threatening to humans. These are some 1400+ known species overall encompasing viruses, bacteria, fungi, protozoa, and helminths. Of that group, we are only interested in those that can be foodborne. Quite simply, if it can't survive in food, it isn't in beer. That knocks out all but bacteria and fungi. Viruses need very specific circumstances to be passed around... like on the lip of a glass or bottle, not the beer in it. **Ahhh...CHOOO!**

Pathogens as a rule are very fastidious beasts. Meaning that they want very specific temperatures, acidity, nutrients and other conditions to thrive.

Bacteria that *could* live in wort, cannot survive even a little bit of fermentation. There are several reasons for this. One is in the 'magic' of hops. It is the isomerized alpha acids that provide a preservative effect to the beer, which happens to inhibit pathogens! Good deal for fresh wort!

Another reason is the drop in pH from fermentation. Next, yeast emit their own enzymes and byproducts, all in an effort to make the environment hostile to other creatures. The major one is alcohol, of course, but their enzymes will break down less vigorous organisms and they become sources of trace nutrition. Now the latter is very minor compared to the effect of alcohol, but it exists! Most of the time these enzymes work on the wort, not organisms until late in the process. Good deal for beer! ...uh, wine too.

Oh, Botulism specifically... did you know that this is an anaerobic pathogen? It's toxin is one of the few that is broken down by boiling. Did you know tht it is strongly inhibited by isomerized alpha acids, even in water? Since fresh wort has a healthy amount of oxygen in it, the beastie cannot even get started, then once the O2 is used up, it doesn't have a chance against the hops or the yeast.

All that is left are a handful of acid producing bacteria that'll ruin a batch of beer. Overall, there are less than 200 organisms that can survive in beer and lend flavor effects. None of these for very long, or very often. Lambic being the sole exception, and if pathogens *could* survive, that'd be the style where you find 'em.
 
I have read that you are supposed to pressure-can wort when preserving it, to make sure the botulism spores are dead. I do not have a pressure cooker, so I freeze wort when I save it.

Thanks for the info Revvy. Does this mean that beer is ok, but you still have to be careful with unfermented wort?
 
So all of this information is very encouraging for a recent home brew I made. But I have one more scenario that i don't think has been addressed. I mad an IPA and when i transferred it to the secondary fermenter I added peaches to the carboy and just bottled it last week. I tried it before bottling and it didn't do jack to the flavor but is it possible that I could get botulism from this beer and keel over tomorrow? Note: I did not do anything to the fruit except for peel and core it and add it. Thanks Guys
 
So all of this information is very encouraging for a recent home brew I made. But I have one more scenario that i don't think has been addressed. I mad an IPA and when i transferred it to the secondary fermenter I added peaches to the carboy and just bottled it last week. I tried it before bottling and it didn't do jack to the flavor but is it possible that I could get botulism from this beer and keel over tomorrow? Note: I did not do anything to the fruit except for peel and core it and add it. Thanks Guys

*sigh*

No......you put it IN an environment where botulism couldn't grow. If beer can't host botulism, then what you put in the beer won't be able to grow it either.

Besides when was the last time you got botulizm from a fresh peach anyway. Botulism usually turns up in home canning, and rarely in commercial cans....
 
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