Sour Mash Newbie And Hypochondriac - Will My Beer Kill Me?

I'm a huge fan of sour beers but I haven't tried my hand at one until this week when I decided I was going to do a Berliner Weiss via sour mash.

I mashed some 2 Row and White Wheat malt as normal for an hour, lowered the temperature to about 115 and tossed in about 3/4 lb of unmilled grain. I mash in a converted Gatorade 10 gallon round water cooler. I hit it with some CO2, sealed it up and wrapped it in a blanket. Since I was uncomfortable with running a space heater or heating pad unattended, I just let it sit as-is for 3.5 days.

When I opened up the tun yesterday it smelled like vomit, parmesan cheese, and death but I read that's relatively normal for a sour mash so I drained, sparged, and did a full 60-min boil. Cooled, pitched US-05, and put it in my fermentation chamber last night.

I tasted a post-boil sample and I didn't actually find it to be too sour. It did have some odd flavors that followed the nose but I was hoping they would ferment/age out.

Of course I started doing some research this morning and came upon the botulism link to sour-mashing. From what I understand, that's only a concern for no-boil methods but I'm still concerned. Should I just toss this and call it a day?

Don't be afriad, let it go on and condition.

Boiling took care of the nasties. Let it ride!
EDIT: Not completely true, read below

inkman15 said:

When I opened up the tun yesterday it smelled like vomit, parmesan cheese, and death but I read that's relatively normal for a sour mash so I drained, sparged, and did a full 60-min boil.

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No, a well-executed sour mash should smell grainy and lactic.

If you don't want to contaminate your cold-side equipment, consider sour worting with a Lactobacillus brevis culture next time.

youreanimpulse said:

Boiling took care of the nasties. Let it ride!

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Boiling doesn't kill Clostridium botulinum spores. It does however kill active cells and denature the toxin that they produce so they'd be starting from scratch. I believe the number you need to kill the spores is 260F.

Measure the pH of the mix. If it is 4.2 (the number used for canning) or lower, you should be fine. Any higher, and I would feel the need to take extra steps.

Here is also some interesting research on the topic of botulism being inhibited by ethanol: http://www.ncbi.nlm.nih.gov/pubmed/12696684

Thanks for the replies. If i do measure the ph and it's not at that number, does that mean I need to also replace my mash tun?

Ugh - wish I never did this experiment


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bu_gee said:

Boiling doesn't kill Clostridium botulinum spores. It does however kill active cells and denature the toxin that they produce so they'd be starting from scratch. I believe the number you need to kill the spores is 260F.

Measure the pH of the mix. If it is 4.2 (the number used for canning) or lower, you should be fine. Any higher, and I would feel the need to take extra steps.

Here is also some interesting research on the topic of botulism being inhibited by ethanol: http://www.ncbi.nlm.nih.gov/pubmed/12696684

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And you learn something new every day. Maybe lower ph with acid if not in range?

Same goes for everything that touched the wort - I would have to replace:

Mash tun
Better Bottle
Thermometer
10 gallon kettle
5 gallon kettle
Hydrometer
Misc plastic measuring equipment

Is that insane? God I hope I'm wrong





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At worst, you would only have to heat everything to 260 degrees (check to make sure that is in fact the temperature to kill cBot - I thought it was 240, but it could be 260). Or, sanitise it in a bleach solution (hell, even Star San would probably work - remember, it is designed to SANITISE).

Having said that, the huge likelihood is everything is FINE. cBot is only a problem in an anaerobic (no oxygen) environment. LActic fermentation is the same process that is used for making pickles, sauerkraut yoghurt (I think), sourdough bread and a hundred other things - precisely because it "sours" things and turns them into a harsh environment for creepie-crawlies. If it was that easy to kill yourself doing it, it wouldn't be a method that has been in use for the last several thousand years.

According to the University of California Santa Barbara's website Botulinum is killed at 120 degrees Celsius (which equals about 248 degrees Fahrenheit) maintained for 30 minutes.

Inkman - With all sincerity, I'd test the pH first, and then let us know what you have. You might be surprised. Between the alcohol and the acidic quality of a beer such as this, I really don't think you have a single thing to worry about.

Getting some ph strips now. Question - does fermentation change ph? Since I've boiled and pitched yeast, will taking a ph reading from the fermenter match what it was in the mash tun?


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Ok - so I took a sample and the pH strip stayed blue, which would indicate that it's 4.4 or higher. That's bad. Worse, I took a couple sips of it post boil last night.


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Okay, so it's not as sour as you want it to be, evidently. That can either be fixed, or it might need to sour more/longer. No big deal. We're talking about two tenths of a point here, so it might be completely fine. Someone with more experience than I have can advise you where this is concerned. Also, the pH requirements for this beer might be less stringent than the levels required for canning, due to the alcohol or other factors.

In a worst case scenario, all you're going to have to do is throw the batch out and clean your equipment, but wait until you hear more from folks who are experienced with Berliner Weisse - it could be entirely fine.

As for your tasting it, do not worry. Keep in mind that cBot needs an anaerobic environment to even exist. Everything is fine.

Thanks for your reply. There's no way that my mash tun was devoid of oxygen. So if it's true that botulism needs to be in an oxygen free environment to exist, I should be okay on that front. I think I'm going to bake my kettles in the oven just to feel better about those. Mash tun is another story


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To be honest, if this was a valid concern you'd hear about it way more often than you do. It's just not something worth worrying about.

As far as your equipment is concerned, I'd follow your normal cleaning and sanitizing procedures and call it a day.

inkman15 said:

Same goes for everything that touched the wort - I would have to replace:

Mash tun
Better Bottle
Thermometer
10 gallon kettle
5 gallon kettle
Hydrometer
Misc plastic measuring equipment

Is that insane? God I hope I'm wrong

Sent from my iPhone using Home Brew

Click to expand...

Freak out time:

C. botulinum spores are everywhere around you especially in pretty much every agricultural product, particularly honey. Also, in its spore state, the only thing that really will touch it is heat. That is to say that bleach won't do much in the spore state either.

Time to take a deep breath and relax:

It really does need a very specific set of conditions for it to pose a danger to you. C. botulinum is NOT an obligate anerobe which means that it doesn't NEED an oxygen-free environment, but it is only able to produce its toxin in the absence of oxygen. It also needs the right conditions for a relatively long period of time to produce enough of the toxin to cause you ill effects. Also, the fact that you haven't dropped dead yet is a pretty good indication that you haven't been poisoned.

Here is the bottom line: When you boiled what was in that container, you denatured all of the toxin and killed all of the active botulism cells. When you oxygenated your wort pitched your yeast, you created an oxygenated environment with an army of microorganisms that is hostile towards C. botulinum. The likelihood that you will get botulism is extremely low. Not zero, but extremely low. I would guess that it is so low that there have probably been only a handful of cases from beer in the past 50 or so years since we came to understand how botulism works.

As for your tools: Don't worry about them. They had the botulinum spores before this experiment. You will always be boiling what comes into contact with those tools and unless you keep stuff in them for extended periods of time without oxygen, you won't have the right environment for generating meaningful amounts of the toxin.

jwelch1103 said:

According to the University of California Santa Barbara's website Botulinum is killed at 120 degrees Celsius (which equals about 248 degrees Fahrenheit) maintained for 30 minutes.

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240F is the temperature for home pressure canners can provide and the recommendation is a 30-minute hold at that temperature.

Commercial canners use 250F for 3-minutes. Apparently this leaves only 1 of a trillion spores viable.

I can't find the source now, but ISTR that you could also do 260F for 2-seconds. That is suspiciously similar to UHT pasteurization, so I may be mistaken or they may be the same thing.

Not to pile on along with the people telling you to just suck it up and not worry...but let me put it to you this way -

Do you eat beef that's cooked anything less than well done? Have you eaten over easy or sunny side up eggs (or over medium for that matter)? Ever licked a beater clean of cake batter or eaten raw cookie dough? Eaten salad where you didn't grow the lettuce? For that matter, while not as common, have you ever eaten sushi/sashimi (actually prepared with raw fish, not vegetarian/California roll), or even, heaven forbid, eaten carpaccio or steak tartare? E. coli and salmonella, and to a lesser extent listeria and some other bacteria are much bigger concerns. If you're that worried about getting sick from food/drink don't EVER go out to eat (and if you do...oddly enough, stick to fast food restaurants where the food prep area is observable to the public...the dirtiest places I've ever seen are all either "fast casual" or even higher end, not fast food) and furthermore, grow all your own food...your beer will be probably one of the safest things you ever consume.

All of those are more dangerous, IMO, than what you're risking with a sour mashed beer. (Not trying to sound like a know-it-all, but I'm a chef and I deal with all of the above on a pretty regular basis). I've also canned tomatoes/salsa without a pressure canner OR added acid of any kind and never had a problem. Of course it only takes one time to cause a problem, but the odds are so small, given the alcohol content and relatively low pH, that I can't see there ever being a problem.

Things I won't mess with, especially professionally (at work, not at home) - foil wrapped baked potatoes that aren't unwrapped and cooled QUICKLY, garlic and oil mixtures/infusions that are heated, but not to a high temperature. Those are your most likely sources of botulism poisioning

Just remember, if you're really that worried about the insanely low chance of botulism from a sour mash, never drive a car after drinking more than 1 beer (buzzed driving IS drunk driving after all)...for that matter, don't drink more than about 5 or so beers a week because, heck, it may damage your liver.

RDWHAHB

Also, I can't help but think of the Eddie Izzard bit about "cake or death," except this is "beer or death."

Great timing for this discussion. I'm planning on sour mashing a Berliner weisse next week using a similar method (the one described by Sean Coates on his blog that doesn't seem to work right now*) and I'm a bit concerned about potential botulism or something equally awful.

I don't have a kegging setup, so have no CO2 to flood the mash tun, and am hoping that covering with cling film and possibly filling the rest of the space with foam or something covered in cling film will be sufficient.

Not wanting to derail the thread, and most of my concerns about causing myself harm have been allayed, but any other tips for a Berliner first timer?

* Since the blog is down, the process is: mash unmilled grain in a thick mash, let it convert and cool, add more unmilled grain, adding a bit more hot water every 8 hours over the next couple of days to keep the mash temperature up, boil for 15 minutes and ferment warm with something clean like US-05.

bu_gee said:

Freak out time:

C. botulinum spores are everywhere around you especially in pretty much every agricultural product, particularly honey. Also, in its spore state, the only thing that really will touch it is heat. That is to say that bleach won't do much in the spore state either.

Time to take a deep breath and relax:

It really does need a very specific set of conditions for it to pose a danger to you. C. botulinum is NOT an obligate anerobe which means that it doesn't NEED an oxygen-free environment, but it is only able to produce its toxin in the absence of oxygen. It also needs the right conditions for a relatively long period of time to produce enough of the toxin to cause you ill effects. Also, the fact that you haven't dropped dead yet is a pretty good indication that you haven't been poisoned.

Here is the bottom line: When you boiled what was in that container, you denatured all of the toxin and killed all of the active botulism cells. When you oxygenated your wort pitched your yeast, you created an oxygenated environment with an army of microorganisms that is hostile towards C. botulinum. The likelihood that you will get botulism is extremely low. Not zero, but extremely low. I would guess that it is so low that there have probably been only a handful of cases from beer in the past 50 or so years since we came to understand how botulism works.

As for your tools: Don't worry about them. They had the botulinum spores before this experiment. You will always be boiling what comes into contact with those tools and unless you keep stuff in them for extended periods of time without oxygen, you won't have the right environment for generating meaningful amounts of the toxin.

Click to expand...

I'm pretty sure the figure you're looking for is "zero". As in, zero report cases resulting from beer, sour mashed or otherwise.

Botulism in the normal brewing process is pretty much impossible. Sour mashing it's so remote and the time frame so short that yeah, while it's not zero, it's so close to zero that it's not even worth considering. Time frame is too short, still too much oxygen, and ideally a lowering pH.

The issue I'd foresee is no-chill brewing where the wort sits in a jerrycan for months on end, or canning real wort starters w/out a pressure canner. And yet, folks have done both for a long time and still no cases.

To me, it's a "technically possible but so unlikely that the odds are probably on par with getting struck by lightening twice while walking to the store to redeem your multi-million-dollar-winning lottery ticket" kind of scenario. Food-borne botulism poisoning is rare to begin with.

As far as vomit and cheese and all that, what I do when sour mashing is conversion rest, drop it to 110, drop the pH with lactic acid to 4.4, pitch a handful of crushed base malt, cover with saran wrap, and let it go for 4 days. I'll then periodically add infusions of boiling water to keep the temp up at about 110. The reason for dropping the pH isn't botulism, but rather it keeps all the nasty enteric microbes at bay, preventing the vomit and diaper nasty stuff. Then I lauter and boil, and go on my way. If I plan on leaving something souring long term, I won't bother with a sour mash, just brew like normal and pitch bugs (dregs, smack pack/vial, whatever) in the fermenter.

Qhrumphf said:

As far as vomit and cheese and all that, what I do when sour mashing is conversion rest, drop it to 110, drop the pH with lactic acid to 4.4, pitch a handful of crushed base malt, cover with saran wrap, and let it go for 4 days. I'll then periodically add infusions of boiling water to keep the temp up at about 110.

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So you don't bother with CO2 in the mash tun or anything? About the only way the method I'm planning on using differs from yours is you add lactic acid.

The LHBS sells "lactic acid 88%", which I presume is about the same. How much do you add to a batch?

Qhrumphf said:

I'm pretty sure the figure you're looking for is "zero". As in, zero report cases resulting from beer, sour mashed or otherwise.

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It obviously isn't actually "zero" because in the OP he mentions finding references to it happening from sour mash at all.

Understand and respect the beast. Don't dismiss it.

Don't go out of your way to create a favorable environment for it without understanding what you can do to mitigate your risk.

At the end of the day, beer making is one huge microbiological experiment and you should treat it as such. The ethanol that we're after in this process is a defense mechanism for the Saccharomyces in the exact same way that botulism toxin is a defense mechanism for C. botulinum.

Thank you all for the lengthy and informed replies. At this point, it has been about 36 hours later and I'm still alive so hopefully I'm in the clear. As I said initially, I'm prone to hypochondria especially when there's even a minor chance of something bad going wrong but all of this discussion has helped put me at ease.

That said, I did bake both of my kettles in the oven at 450 for 45-60 minutes just for my sanity's sake. The mash tun sat in soap for hours and is now has been sitting in OxyClean overnight. I'm probably going to dump the batch and toss the Better Bottle since - cBot or no cBot - it's going to stink like high hell.

Lesson learned and next time I decide I want to try a sour, I think I'm going to get some sour-dedicated equipment and pitch the cultures on the cold side.

inkman15 said:

... I'm probably going to dump the batch and toss the Better Bottle since - cBot or no cBot - it's going to stink like high hell.

Lesson learned and next time I decide I want to try a sour, I think I'm going to get some sour-dedicated equipment and pitch the cultures on the cold side.

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Just to put your mind at ease (or not as the case may be), if you've made beer before, you've brewed botulism toxin before; you've just never made enough for it to be dangerous at least not in the quantities consumed in one sitting. They're also there in commercial beers.

If you're gonna toss the bottle anyway, I'd let it brew out and see what you get. You don't gain anything by dumping early.

bu_gee said:

Just to put your mind at ease (or not as the case may be), if you've made beer before, you've brewed botulism toxin before; you've just never made enough for it to be dangerous at least not in the quantities consumed in one sitting. They're also there in commercial beers.

If you're gonna toss the bottle anyway, I'd let it brew out and see what you get. You don't gain anything by dumping early.

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Fair enough - yeah, I'll let it ferment out and see how it is. Worst case is it's alcoholic vomit and parmesan

inkman15 said:

Fair enough - yeah, I'll let it ferment out and see how it is. Worst case is it's alcoholic vomit and parmesan

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If it's still bad add some brett. It will clean it up in a few months. Chad has a sour mash that he ferments that way.

bu_gee said:

It obviously isn't actually "zero" because in the OP he mentions finding references to it happening from sour mash at all.

Understand and respect the beast. Don't dismiss it.

Don't go out of your way to create a favorable environment for it without understanding what you can do to mitigate your risk.

At the end of the day, beer making is one huge microbiological experiment and you should treat it as such. The ethanol that we're after in this process is a defense mechanism for the Saccharomyces in the exact same way that botulism toxin is a defense mechanism for C. botulinum.

Click to expand...

I may not have been clear. The risk is not zero. The reported instances is zero. It's mentioned because its possible albeit unbeliebably unlikely.

hijukal said:

So you don't bother with CO2 in the mash tun or anything? About the only way the method I'm planning on using differs from yours is you add lactic acid.

The LHBS sells "lactic acid 88%", which I presume is about the same. How much do you add to a batch?

Click to expand...

I don't have a CO2 set up. If I did, I would absolutely blanket. Sarab wrap is a poor substitute but its what I have to work with.

And I use 88% lactic acid, play with the settings in Bru'n Water to give me a ballpark idea, and verify with pH meter as I go. Don't have notes in front of me but it works out to a few ml of 88% lactic.

Qhrumphf said:

I don't have a CO2 set up. If I did, I would absolutely blanket. Sarab wrap is a poor substitute but its what I have to work with.

And I use 88% lactic acid, play with the settings in Bru'n Water to give me a ballpark idea, and verify with pH meter as I go. Don't have notes in front of me but it works out to a few ml of 88% lactic.

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Excellent, thanks a lot for your help. Also checked out Bru'n Water, which seems quite useful (though I think I'll refrain from additions for at least this first Berliner).