Wort pH and Risk of Botulism

[marc1]

That's a good suggestion. I have a single element induction 'burner' we used in our motor home, but don't use anymore since our new RV came with a built-in induction range. It would achieve two goals: simplify making starter, and keeping the process out of SWMBO's kitchen. Win-win.

Not quite as easy as boiling in a 2L Erlenmeyer, but certainly less likely to suffer boil-over.

Brooo Brother

They make induction compatible pressure canners, but it's more equipment to buy. Payoff vs buying canned starter would be a while unless you'd use it for other things.

 

[Vale71]

I was wondering how concentrated you’d need to make wort to prevent spores from growing. This link shows some correlation between aw and sugar concentration:
https://ucfoodsafety.ucdavis.edu/sites/g/files/dgvnsk7366/files/inline-files/133655.pdf

Commercial LME has an SG of 1.4 and that's deemed safe so I'd say at least as concentrated as LME. Of course you're better off buying LME instead of making it yourself which would be impractical and qualitatively inferior.

 

[chipmunk]

Sounds reasonable. But wouldn't you just be boiling down LME to make just more LME

True - I was originally thinking by designing a concentrated wort, you might be able to forego the acid treatment, but it looks like you have to get into very high sugar concentrations before that would be safe.

Adding another layer of complexity by requiring buffering of the starter wort further complicates the work flow. Increasingly it appears that the best course of action is to just keep making starters ad hoc on a brew by brew basis (or keep purchasing Propper) until I can have a "proper" wort canning session. Thanks for the insight.

You might be able to achieve your original objective without too much complexity in the work flow. Say for example, rather than using your starter directly, you “design” a concentrated wort solution, say double your desired gravity, and acidify to 4.6 like your original idea. I was playing around in Beersmith, and according to their acidity calculator, around 1/4tsp of baking soda per liter should be enough to bring the wort pH up to “normal” ranges. So when you want to make a starter, take a 1L jar of your concentrated wort solution, mix 1:1 with sterile distilled water, add 1/4tsp of baking soda to bring the pH around 5.2 or so, and pitch. Ive never used Propper - but isn’t that kind of the same process other than the baking soda addition?

 

[Broothru]

True - I was originally thinking by designing a concentrated wort, you might be able to forego the acid treatment, but it looks like you have to get into very high sugar concentrations before that would be safe.

You might be able to achieve your original objective without too much complexity in the work flow. Say for example, rather than using your starter directly, you “design” a concentrated wort solution, say double your desired gravity, and acidify to 4.6 like your original idea. I was playing around in Beersmith, and according to their acidity calculator, around 1/4tsp of baking soda per liter should be enough to bring the wort pH up to “normal” ranges. So when you want to make a starter, take a 1L jar of your concentrated wort solution, mix 1:1 with sterile distilled water, add 1/4tsp of baking soda to bring the pH around 5.2 or so, and pitch. Ive never used Propper - but isn’t that kind of the same process other than the baking soda addition?

I hadn't considered that Propper is simply a higher Brix wort (Duh?), but of course that's exactly all it is. So if I made a more concentrated (higher Brix) starter wort for canning, I could also acidify to a pH lower that 4.6 to be able to 'boil can' rather than pressure can the wort. Then when ready to make a starter, the wort (which will be reconstituted to a lower Brix) could be made more alkaline with distilled water that had been buffered. It could be diluted to a usable S.G and a pH around ~5.2 in one step. That's a very interesting idea.

It seems as if it should work. Of course it's always with the caveat that there could be a hole in both my logic and the depth to which my knowledge base extends into food safety and basic brewing chemistry. @Vale, care to weight in with an educated opinion?

 

[Vale71]

It seems as if it should work. Of course it's always with the caveat that there could be a hole in both my logic and the depth to which my knowledge base extends into food safety and basic brewing chemistry. @Vale, care to weight in with an educated opinion?

Without proper heat treatment your canned wort would still be exposed to a wide range of organisms that thrive at that PH and can generate spores that will survive simple boiling. Think Brettanomyces but also wild yeast that can still form spores that in time might become active again and feast on all the available simple sugars. Unlike botulism they most certainly won't kill you but might still render your canned wort unusable in a relatively short time.

 

[chipmunk]

I was thinking about Botulism and risk - and one element that wasn’t really discussed is the ability to detect if there was an infection. So for example, in food canning, there’s a jar full of complex colours and textures - so might be challenging to notice an infection. Contrast that with wort - it’s normally a clear liquid. Is it even possible to have an infection without it being kind of obvious - I.e., cloudy, blown seals, or having clumps of floating snot?

 

[Broothru]

Without proper heat treatment your canned wort would still be exposed to a wide range of organisms that thrive at that PH and can generate spores that will survive simple boiling. Think Brettanomyces but also wild yeast that can still form spores that in time might become active again and feast on all the available simple sugars. Unlike botulism they most certainly won't kill you but might still render your canned wort unusable in a relatively short time.

I can't argue that there's no shortage of airborne wild yeast or other spoilage microorganisms that can infect a boil-only heat processed wort starter. My question is how this differs from any other high acid food stuff canned in a hot water bath.

I would think that some DME placed in a sanitized jar with a liter of distilled water and an ml or two of lactic acid has a much less risk of infection than a jar of tomatoes. Yet we "safely" can and consume these items after months on an unrefrigerated shelf.

If a bacterial infection does proliferate or mold/wild yeast gain a foothold, that condition readily shows itself. That said, I've never had to throw out any home canned items, except for a case of three-year-old tomatoes that I oncovered once. They looked OK, but got tossed out of an abundance of caution.

I'm sure there're valid reasons for not trying this process. It's just not convincingly clear yet.

Brooo Brother

 

[Silver_Is_Money]

If botulism is a real concern, why guess at what will may prevent it? Why not simply make up a fresh DME based starter for each new brewing session?

 

[Broothru]

If botulism is a real concern, why guess at what will may prevent it? Why not simply make up a fresh DME based starter for each new brewing session?

I guess as much as anything else, I'm what I'd call a "process" brewer. I like beer, but I really like brewing beer. Tinkering with the process is part of the enjoyment for me. Streamlining the process answers the hypothetical question I'm always pondering, "Can I do that?"

"Can I" is always tempered with "Should I", as well as "What's the downside."

So I guess I'm at the 'downside' stage. Intellectual curiosity. But just as curiosity killed the cat, this 'cat' would rather remain in this dimension for the time being.

Brooo Brother

 

[Vale71]

I can't argue that there's no shortage of airborne wild yeast or other spoilage microorganisms that can infect a boil-only heat processed wort starter. My question is how this differs from any other high acid food stuff canned in a hot water bath.

1 - available water
2 - huge amount of simple, easily digestible sugars

A jar of canned tomatoes has a negligible amount of carbohydrates compared to a 12°P wort. When canning wort you're basically canning an ideal culture medium for all sorts of bugs and that's a lot more crtitical than canning vegetables.

 

[Broothru]

So the take-away is to pressure can my starter worts to eliminate botulism spores as well as opportunistic bacteria and wild yeast. There is no shortcut to science that provides an equivalent measure of safety. Though the overall risk seems low, it doesn't warrant the statistical chance of things going south. 250F + for :20 minutes it is!

Brooo Brother

 

[Birrofilo]

I think microwave ovens are the most overlooked device we homebrewers have at home.
4 minutes in a microwave at 900W are guaranteed to kill anything that was attempting to gain a living in your wort, and also to degrade the botulinus toxines, besides killing the spores.

A Microwave oven is also very good to sanitize (or actually sterilize, if you so wish) metal objects such as metallic taps (I have two metallic fermenters with metallic taps) during your pre-brewing routine. Just immerse the tap in a microwave-oven-suitable bowl letting it completely immersed in water, and put the bowl in the microwave oven, and let it go (watch the process: the water might boil and overflow, then stop, use a larger container and a larger quantity of water, repeat).

1 minute will sanitize adequately, 4 minutes will kill any form of life discovered by science since the times of Saint Louis Pasteur.

I never tried with borosilicate glass, but I do presume one can succesfully sanitize borosilicate-glass objects. Best is to immerse the object in water so that it is also surrounded by boiling water, lest "Hot spots" in the oven heat the object irregularly and stress the borosilicate glass.

Life uses water. Bacteria and such creatures are made of a membrane which contains water-rich living matter.

When you use a microwave oven, the microwaves cause the water inside the creature to boil, that creates gas bubbles which literally burst the microbe, that works also at a microscopic level. In a microwave, microbes have no place where to hide. They will die, I tell you.

For what I know, microwave ovens are increasingly used in chemical laboratories for sterilization purposes. It's good stuff.

PS Do not put in the microwave oven any hermetically closed container because it will explode.

 

[madscientist451]

Sorry, I don't get it, why go though a big hassle to make a canned wort for a starter? I take a quart of water, heat it to just below boiling, toss in some DME, put the lid on the pot and in the morning I dump it into a 1/2 gallon jug and toss in the yeast. Why would I want to go through all the extra work to make canned starter wort that might cause some problems?

 

[Birrofilo]

I don't get it myself as well, but the OP gave an answer in post #39, which can be summarized in "it's not the destination, it's the road" stuff.

 

[madscientist451]

Oh ok, now I get it, let's do things the "hard way".

 

[bu_gee]

Sorry to show up late to the party, but it was my understanding that the botulism toxin is easily denatured. A quick perusal of the Googletron seems to indicate 85°C for 5 minutes is sufficient.

So with that in mind, I would like to propose an alternative: Pressure can your wort with your Fagor and make yourself a war chest. Between the day before you need it and 2 hours before you need it, pop it either back in the pressure canner (I like the Instant Pot for this) or a water bath to denature any potential toxin, chill in an ice bath, and pop it in the refrigerator. The cold will keep the C. botulini from getting too frisky before you use it the next day.

 

[marc1]

I think microwave ovens are the most overlooked device we homebrewers have at home.
4 minutes in a microwave at 900W are guaranteed to kill anything that was attempting to gain a living in your wort, and also to degrade the botulinus toxines, besides killing the spores.

A Microwave oven is also very good to sanitize (or actually sterilize, if you so wish) metal objects such as metallic taps (I have two metallic fermenters with metallic taps) during your pre-brewing routine. Just immerse the tap in a microwave-oven-suitable bowl letting it completely immersed in water, and put the bowl in the microwave oven, and let it go (watch the process: the water might boil and overflow, then stop, use a larger container and a larger quantity of water, repeat).

1 minute will sanitize adequately, 4 minutes will kill any form of life discovered by science since the times of Saint Louis Pasteur.

I never tried with borosilicate glass, but I do presume one can succesfully sanitize borosilicate-glass objects. Best is to immerse the object in water so that it is also surrounded by boiling water, lest "Hot spots" in the oven heat the object irregularly and stress the borosilicate glass.

Life uses water. Bacteria and such creatures are made of a membrane which contains water-rich living matter.

When you use a microwave oven, the microwaves cause the water inside the creature to boil, that creates gas bubbles which literally burst the microbe, that works also at a microscopic level. In a microwave, microbes have no place where to hide. They will die, I tell you.

For what I know, microwave ovens are increasingly used in chemical laboratories for sterilization purposes. It's good stuff.

PS Do not put in the microwave oven any hermetically closed container because it will explode.

I agree microwaves can be used for sterilization (some searching shows it can be done commercially for food products), but what sources do you have for protocols for home microwave ovens? This is interesting.

Thanks!

 

[marc1]

Sorry to show up late to the party, but it was my understanding that the botulism toxin is easily denatured. A quick perusal of the Googletron seems to indicate 85°C for 5 minutes is sufficient.

So with that in mind, I would like to propose an alternative: Pressure can your wort with your Fagor and make yourself a war chest. Between the day before you need it and 2 hours before you need it, pop it either back in the pressure canner (I like the Instant Pot for this) or a water bath to denature any potential toxin, chill in an ice bath, and pop it in the refrigerator. The cold will keep the C. botulini from getting too frisky before you use it the next day.

This defeats the purpose of having starter wort ready-to-use.

Planning on having jars sitting around that may have deadly poison in them seems like a bad practice.

 

[Vale71]

Planning on having jars sitting around that may have deadly poison in them seems like a bad practice.

Totally agree. This would be just about as safe as having strong caustic or acid solutions stored in a mineral water bottle with a hand-written label that says "poison" pasted on. People have lost the use of their stomach or died because of stupid stuff like that.

 

[Birrofilo]

@bu_gee

For what I remember, Botulinus toxins are degraded with heat, but Botulinus spores are much more resistant to heat than their toxins. If the bacterium is in his "normal" form it can be killed with a normal thermal procedure, but if it is in his "spore" form it needs an "extreme" thermal process to get rid of, because the protein shield will isolate the bacterium from external aggressions and will prolong his time to death when heated. Microwaves will kill it "from the inside" and no protein shield will shield it. Normally you want to get rid not only of spores (which is what actually kills you) but also of the bacterium itself. Survival of the spore is not a problem for beer (boiling for 60' in an acid environment would kill the spore ten times, so to speak) but for other food preparations it is.

@marc1

In my internet wandering in search of information to make life (and brewer's life) easier I do come across sources which I deem reliable, and I take note of the information which is useful for my life. I don't usually take notes about the sources themselves because, you know, I'm not writing a "paper" ;-)

Yet, I do remember having read of chemical laboratories using microwaves for sterilization purposes, from sources which I deemed reputable. Chemical laboratories have a large need for sterilization means and for what I remember microwave ovens are making some sort of "small revolution" in the field, a bit like "all in one" kettles are doing in our field ;-)

People is often put off by the notorious incompatibility between microwaves ovens and iron or steel items. But that is a misconception. If you immerse in water the metal or the object, there will be no problem at all.

The usefulness of this procedure is very high not only for metal objects and for borosilicate glass, but also for small silicon hoses. E.g. you can sterilize your aeration stone with all the silicon hose attached to it. That's not just practical, but you can also avoid touching the stone to fit the silicon hose again after having sterilized the stone alone. Just put everything in a bowel filled with water and that's it, your stone is ready for use and perfectly sterilized, and you use no sanitizing agent risking to obstruct its pores.

 

[bu_gee]

@bu_gee

For what I remember, Botulinus toxins are degraded with heat, but Botulinus spores are much more resistant to heat than their toxins. If the bacterium is in his "normal" form it can be killed with a normal thermal procedure, but if it is in his "spore" form it needs an "extreme" thermal process to get rid of, because the protein shield will isolate the bacterium from external aggressions and will prolong his time to death when heated. Microwaves will kill it "from the inside" and no protein shield will shield it. Normally you want to get rid not only of spores (which is what actually kills you) but also of the bacterium itself. Survival of the spore is not a problem for beer (boiling for 60' in an acid environment would kill the spore ten times, so to speak) but for other food preparations it is.

I should stress that I'm not a microbiologist here, but from what I remember about it, the botulism toxin is only created when the bacteria goes into its spore form. Getting rid of the bacteria or the spore isn't entirely necessary as once it is in our digestive systems, it no longer poses a risk to us. It is really the toxin itself that causes the problem. If spores actually caused us problems we wouldn't be able to eat any agricultural products, particularly honey, because the spores are all over them.

I had merely posed it as an intermediate solution. Not perfect, but far closer to a ready to use product than a bag of DME.

As for microwave sterilization, and this may have been said before, I would be nervous without an adequate laboratory to determine if the process did actually work. Commercial canning companies with all the equipment will all the bells and whistles still check all of their products susceptible to C. botulini just to be sure because that process isn't exactly 100% either.

 

[Birrofilo]

@bu_gee

If the bacterium remains alive, through your knives, forks etc. it can infect some other food. There it can turn into the spore form and create the toxin which might kill you.
You normally want to kill the problem at the source, you want to minimize the Botulinum which is hanging around.
To state it in another way, it's not the terrorist which kills you, it's the explosive, but in order to avoid terrorist explosions you have to chase terrorists, not only explosives ;-)

 

[bu_gee]

@bu_gee

If the bacterium remains alive, through your knives, forks etc. it can infect some other food. There it can turn into the spore form and create the toxin which might kill you.
You normally want to kill the problem at the source, you want to minimize the Botulinum which is hanging around.
To state it in another way, it's not the terrorist which kills you, it's the explosive, but in order to avoid terrorist explosions you have to chase terrorists, not only explosives ;-)

To extend your metaphor: You don't need to kill the terrorist. Forcing him into hiding is sufficient.

What does it take to force him into hiding? Oxygen is sufficient as the Clostridium genus are all obligate anaerobes. Acid (in your gut) and ethanol (in your beer) helps too.

 

[twd000]

the microwave sterilization is interesting. Have you found a time-and-temperature table for various materials and container sizes? If I had a quart jar of wort, how long would I need to microwave on high to sterilize it all the way through?

 

[Birrofilo]

To extend your metaphor: You don't need to kill the terrorist. Forcing him into hiding is sufficient.

What does it take to force him into hiding? Oxygen is sufficient as the clostridium genus are all obligate anaerobes. Acid (in your gut) and ethanol (in your beer) helps too.

Although we have a different take on terrorism ;-) that's very interesting.
I suppose you mean that Botulinum can be eliminated through means such as oxygenated water, or pure oxygen from cylinders, if the substrate is liquid.

This leads me to another question which risks derailing the thread astray: I promise the OP I will open a new thread if the answer is not fast and definitive.
The OT question is: does oxygenation with pure oxygen "sanitize" the wort or not?
If yes, there is a huge advantage in using an O2 cylinder rather than a fish tank pump.

 

[bu_gee]

Although we have a different take on terrorism ;-) that's very interesting.
I suppose you mean that Botulinum can be eliminated through means such as oxygenated water, or pure oxygen from cylinders, if the substrate is liquid.

This leads me to another question which risks derailing the thread astray: I promise the OP I will open a new thread if the answer is not fast and definitive.
The OT question is: does oxygenation with pure oxygen "sanitize" the wort or not?
If yes, there is a huge advantage in using an O2 cylinder rather than a fish tank pump.

Oxygen is tricky as it oxidizes everything it comes into contact with and in a trapped environment, such as a sealed jar, you will eventually consume it all in regular chemical reactions and eventually leave a hospitable environment for C. botulini.

You will need a constant, if small, supply of oxygen to keep the bacteria safely in their spore form. The atmosphere does a good job of that so we don't usually have to worry about botulism poisoning from knifes and forks and the sort. We're just victims of our own ingenuity that we're creating a hospitable environment in a sealed jar.

While oxygen will force the bacteria back into spore form, I don't believe that oxygen will oxidize toxin that is generated, at least not at a reasonable rate. So if you have an environment where you may have had active C. botulini, you probably want to use heat since it both forces the bacteria to form spores and destroys the toxin.

 

[bu_gee]

the microwave sterilization is interesting. Have you found a time-and-temperature table for various materials and container sizes? If I had a quart jar of wort, how long would I need to microwave on high to sterilize it all the way through?

I'm willing to bet that this unicorn doesn't exist, at least not in generic form. Heck, more and more foods are shying away from microwave instructions just because of the number of variables involved in microwave ovens.

Saying that something that works in my microwave oven will work in yours is a stretch at best, and deadly at worst.

 

[Vale71]

Survival of the spore is not a problem for beer (boiling for 60' in an acid environment would kill the spore ten times, so to speak) but for other food preparations it is.

This information is incorrect and very dangerous so please stop propagating it. Boiling at standard temperature and pressure no matter for how long will not kill C.botulinum spores and wort is not acidic enough to prevent the spores from becoming active and starting an infection which can then create the toxin itself. This is one of the reasons why storing wort after a simple boil is dangerous and that's what this thread is all about.
In brewing practice this is not a problem as you'd pitch yeast right away and this will quickly cause the PH to drop to a level that makes C.botulinum spores no longer viable, so even if they're still there there is no danger of beer becoming infected. When you are storing wort and not beer this does not apply and a different sterilization process need to be followed for the stored wort to be both shelf stable as well as safe for later human consumption.

 

[z-bob]

There's one other thing you can do that everyone seems to have overlooked. You can autoclave your acid but not acid enough wort at almost but not high enough temperature. It will be unlikely to spoil but you can't trust it. When you're ready to use it, you will have to boil it first to denature any botulinum toxin that might possibly be there. (it's extremely unlikely, but you don't want chance it) Boiling destroys the toxin and kills the bacteria.

I don't remember how long you have to boil it; 10 minutes comes to mind but I don't think it's really that long. You'll have to look that up. It should be easy to find now that you know to look for it HTH

Obviously, if the seal has failed and the wort is cloudy and smells like vomit you'll just pitch it. The danger is if the clostridium has just started to grow before you open the jar and it's not obvious yet.

 

[bu_gee]

This thread here is why we probably shouldn't have botulism conversations on this forum.

Too much misinformation and underrepresentation of the risk makes for a dangerous mix.

Working with yeast gives us all the illusion of being part-time microbiologists, but, fundamentally, 99% of us don't have the equipment to adequately control for something as dangerous as C. botulini and as a result we should treat it with extreme caution.

So, as a PSA, do research using reputable sources to understand what you can and can't do in this respect.

I have done much research and I understand more about botulism than your average idiot, but that just makes me an above average idiot. I just know enough about it for it to scare the crap out of me and to know that I'm not going to actually get rid of it.