sour mash & botulism?

[Calder]

I've seen a number of threads about souring with grains, and trying to exclude O2 to minimize clostridium growth, which causes vomit smells.

In researching canning starter wort, I came across a major concern about the development of Clostridium botulinum which can produce lethal toxins. I'm figuring these are the same thing.

From what I can tell, heating to over 185 will breakdown the toxins. If you boil, you should be ok, if you no-boil, you might want to re-evaluate your methods.

Boiling will not kill the bacteria, but it is not toxic, and low ph will prevent it from producing toxins.

Interested in anyones thoughts.

 

[Sleepyemt]

An interesting write up here on the subject....

Biggest thing would be to get the PH down below 4.6...

http://beerandwinejournal.com/botulism/



Sent from my iPhone using Home Brew

 

[40watt]

I made a spur of the moment decision recently that is ill advised.
I ran a little wort from a sour mash directly into the fermentor just before pitching the ECY 20 blend.

Don't know if the toxins could be produced before the ph drops further.
Either way, it was an unnecessary risk.

Thinking of Chad from Crooked Stave's no boil beer when I did it.

 

[MindenMan]

There are no known pathogens that live in beer, that are harmful to humans.

 

[sweetcell]

There are no known pathogens that live in beer, that are harmful to humans.

this true one alcohol is present and the pH has dropped - both outcomes of fermentation. prior to fermentation, plenty of nasty stuff can inhabit wort.

what 40watt did was add soured (i.e. only partially fermented) wort to his fermenter. eventually the brewers yeast kicked in, overtook any other organizsms and made the beer inhospitable to undesirable agents, but before then, during the souring process, all sorts of bugs could have set up shop, grown their population to significant levels and/or could have created toxins. this is one reason why boiling the soured wort is a desirable. you're not only killing off the lacto but also whatever else might have started to take hold in there.

 

[40watt]

Exactly.
The idea being the organism responsible for botulinum while be overtaken in the fermentation, but any toxins already produced are still present. It only takes a very small amount of that toxin.

 

[dantheman13]

Colby sort of did a follow up to his article on the latest BasicBrewing Radio (http://traffic.libsyn.com/basicbrewing/bbr05-01-14chriswhite.mp3). The part about botulism is in the second half of the show, and Chris White gives his opinion on the topic. Chris also follows up with how long it takes for the botulism toxin to form in wort (3-4 days).

This article was obviously centered around the No Chill brewing method, but I am curious how it applies to spontaneous fermentation?

 

[40watt]

At 3-4 days, I am safe. Even though I had a slow start to my fermentation.

 

[seabass07]

Also consider that sour mashes are from tons of lactobacillus as well as other bacteria. There is significantly more lacto than others. They will significantly drop the pH . I don't see how botulism could take hold in that environment.

 

[Joewalla88]

Now I'm nervous. I was experimenting with a no boil sour. It's fermenting in the basement. I hope it's not poisonous.

 

[40watt]

If it's actually fermenting, that puts you in the clear. Unless it took a very long time to begin fermenting.

 

[Joewalla88]

Well I sour mashed for a few days and then put it in the fermentor. The yeast took off a day or so later I think.

 

[40watt]

In your situation, I do think the lacto would drop the ph pretty quickly in that mash.
Ideally, you would know your ph was below 4.9 to be as safe as you can.

In my case, I believe I had a very low mash ph, but can't be confident in that.
Luckily my ECY culture was doing it's job before it could be a problem.

 

[Joewalla88]

These botulism threads always freak me out.

 

[seabass07]

Think of it this way. A proper regular mash is in the low 5's. It doesn't take much lacto activity to drop it further. There's no reason to freak out. Unfermented wort is a problem. Fermented is not, whether it be fermented with yeast or lactobacillus. Stop worrying. If you're doing the no chill thing, well you end up with a partially emploded container if you do it right. If there is any kind of dangerous activity, there will be gas produced. You'll end up with a swollen container.

If you're extremely worried about allowing other microbes to take hold in a sour mash, make sure you throw in some unmashed grain when it gets down to a reasonable temp. Pale malts are covered in lactobacillus.

 

[dantheman13]

Think of it this way. A proper regular mash is in the low 5's. It doesn't take much lacto activity to drop it further. There's no reason to freak out. Unfermented wort is a problem. Fermented is not, whether it be fermented with yeast or lactobacillus. Stop worrying. If you're doing the no chill thing, well you end up with a partially emploded container if you do it right. If there is any kind of dangerous activity, there will be gas produced. You'll end up with a swollen container.

If you're extremely worried about allowing other microbes to take hold in a sour mash, make sure you throw in some unmashed grain when it gets down to a reasonable temp. Pale malts are covered in lactobacillus.

Well, the concern is the potential botulism toxin that is produced before fermentation begins (or before the pH drops to 4.5-). Toxin that is created before fermentation remains in the beer after fermentation, so the assumption that fermented beer is safe is wrong if the wort used for the fermentation was left aged over 3+ days. Also, according to the article, not all forms of botulism will produce CO2 or expand the container, so there is no guarantee that it is botulism free based on regular human observation.

I believe that most people who do sour mashes only let them go 1-2 days. That is not enough time to allow the botulism bacteria to produce the toxin (according to what I have read). In addition to that, most people will boil after the sour mash, which will denature any botulism toxin that happens to be produced (say if you sour mash for 3+ days). As far as I can tell, you can sour mash for as long as you want, as long as you boil afterwords and create a fermentation within 3 days.

As far as spontaneous fermentation goes, does the pH drop below 4.5 within 3 days? I wish I knew more about spontaneous fermentation!

 

[Joewalla88]

I was under the impression that sour mashing took the PH below the point where botulism can do it's thing. It seems like it wouldn't matter then if it sat for 2 days or 3 days or 4 days or whatever, because the lacto would keep it at bay. After some more reading, it's sounds like botulism cases are very rare. Still I'm a little concerned about the brew I've got going now. It was an experiment to see how easy (or lazy) making a sour beer could be.

I crushed 1 lb of munich and 1lb of vienna and put it in a cooler. I poured in the mash water and closed it, wrapped it in a blanket and left it in the basement. I though I left it for 3 days, but now that I think about it it may have been four. That's why this is getting me a little nervous. I did get it all over myself when I was pouring it into the fermentor, and I'm still alive. I don't know if you actually have to eat the toxin to get sick or not.

I'd hate to dump it. It looks nice and smells great. It's not worth paralysis though.

 

[testingapril]

If there is any kind of dangerous activity, there will be gas produced. You'll end up with a swollen container.

Botulinum does not produce gas when it produces botulinum toxin.

That said, if there is even a slight amount of alcohol present, botulinum can't do it's thing. If the pH is low 4.5ish, botulinum can't do it's thing.

If you've boiled the beer for an hour the only thing left is the chance of botulinum spores which take weeks to germinate and become toxin producers.

If you are doing no-chill, you are fine to leave the beer overnight or even a week, but I wouldn't go any further than that.

If you are doing sour mash, as long as your pH drops within a day or two, you're fine, and with all the lacto that lives on grain, that should be no problem. Ideally, you would drop the ph with some Lactic acid before starting the sour mash to keep clostridium and other funk-ifiers from funking things up while the lacto work.

Bottom line is, if you are doing traditional brewing techniques, whether it's sour mash, or even no-chill, you will be fine. The key is not to stray too far from the norm.

I'm actually the one who kind of sparked this whole botulinum no-chill scare in the Basic Brewing community. I emailed James out of concern after he tasted the no-chill beer that had sat for 4 months before being pitched. Obviously James and his cohorts are fine, but it was a risky thing to do. No-chill brewers should be perfectly fine if they pitch in a reasonable time frame like less than a week after brew day.

 

[40watt]

The danger is very low if not completely absent.
I'm only saying that a ph meter would make me feel better about it.
That's just me though.

I would be much more wary if I were a no chill brewer or canning wort.
In canning wort, you need to use the right equipment and give the process plenty of time.

I simply don't have the balls to do what the no chill guys are doing.
Also, why risk giving homebrew a bad name by making someone sick...

 

[testingapril]

I was under the impression that sour mashing took the PH below the point where botulism can do it's thing. It seems like it wouldn't matter then if it sat for 2 days or 3 days or 4 days or whatever, because the lacto would keep it at bay. After some more reading, it's sounds like botulism cases are very rare. Still I'm a little concerned about the brew I've got going now. It was an experiment to see how easy (or lazy) making a sour beer could be.

I crushed 1 lb of munich and 1lb of vienna and put it in a cooler. I poured in the mash water and closed it, wrapped it in a blanket and left it in the basement. I though I left it for 3 days, but now that I think about it it may have been four. That's why this is getting me a little nervous. I did get it all over myself when I was pouring it into the fermentor, and I'm still alive. I don't know if you actually have to eat the toxin to get sick or not.

I'd hate to dump it. It looks nice and smells great. It's not worth paralysis though.

If it tastes even remotely sour, the pH is WAY below what botulinum can work in, so you should be fine.

You would need to consume the toxin to become ill.

And yes, botulism cases are extremely rare, and, in the US, are always traceable back to poor home canning procedure. Botulinum are not like lacto and wild yeasts that cover every surface on the planet. They are all over, but not like fermentative bugs. They are also fairly easily killed. It's the spores that are dang near impossible to kill, and the spores take weeks to germinate and become toxin producers.

 

[Joewalla88]

Thanks for easing my mind about this. I just have one more question. The reason I left it in the sour mash for longer than two days is because I didn't have a good way to keep it at 100-120 degrees. So I just let it sour at room temp for longer. Would there be any real reason to be concerned with the lacto dropping the PH low enough & fast enough at 65ish degrees?

I just took a taste of it and it's really sour, but it's been fermenting a couple weeks now.

 

[Joewalla88]

Well, I guess since I took a little drink and didn't get sick or die than it must be okay.

 

[40watt]

Well, I guess since I took a little drink and didn't get sick or die than it must be okay.

Well done! That approach got the human race by for millennia!

 

[RachmaelBenApplebaum]

Well done! That approach got the human race by for millennia!

As someone who ferments vegetables at home, haven't gotten sick, and gets weird looks from folks who think I'm crazy for eating purposely rotten cabbage, I commend you for pointing this out. I'm all for safety, but sometimes threats are grossly overstated. Like someone said earlier, as long as you aren't straying too far from the norm, you'll live.

 

[40watt]

I swear I'm making some kraut and kimchi when I can remember to do it!