twd000
Well-Known Member
instead of trying to make it shelf-stable, why not store the wort in the fridge until brew day? Botulinum won't grow below 40F
Wort pH and Risk of Botulism
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Rate x Time => A slow rate for a long time poses similar risk as a fast rate for a short time.
In my case, it's because I have 200# of malt in my basement and only about a half a pound of DME left. So I want to figure out a process to use what I have already. And to enjoy the ride
Anybody willing to bet their life on it?
You do all the time.
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With botulism? *citation needed
It's both. Jar of chicken stock in the fridge with a layer of fat on top, waiting to be made into soup? Maybe just I do that. OTOH, it will get boiled before it's eaten. Another example is supermarket canned hams that must be kept refrigerated.
I don't want to argue with you; I generally agree with you. But there are ways to mitigate risks.
A layer of fat is permeable to oxygen which by itself will stifle C. botulini which is likely already in the stock, but it offers a substantial barrier to other bacteria entering. If you vacuum seal that jar, that changes the equation which is a good reason to not seal it, but boiling it before using it should be fine and it isn't exactly betting your life on it
Every canned ham I've ever bought was "refrigerate after opening" so I can't agree or disagree with you on that respect.n
After my last post I rifled through my refrigerator trying to find anything that is completely sealed from oxygen, not commercially canned, and won't be cooked before eating and I found none, but maybe that's just my fridge. The closest thing I found was a vacuum sealed pack of pork.
No I don't, because my refrigerator, just like any other, is a very oxygen-rich environment.
The small canned hams are shelf-stable (just like SPAM.) I saw some at Aldi last week. The big ones are sold in the refrigerated case to prevent spoilage. I assume that includes botulism, but maybe they have enough nitrites added to prevent that. (I haven't seen a refrigerated canned ham in years because I don't look for them)
I know enough to know that I know a little but probably not much I guess it's part of that Dunning-Krueger thing; the more that I learn the less that I know. Food preservation was one of my things back in the Usenet days.
I know enough to know that I know a little but probably not much
I guess it's part of that Dunning-Krueger thing; the more that I learn the less that I know. Food preservation was one of my things back in the Usenet days.
My general guidelines is that 4 minutes kills everything and their dog. Your mileage may vary. Normally we don't need sterilization but sanitization. For that, 1 minute is sufficient. This is again from my notes, but I cannot point to specific sources, so use this information at your own peril, so to speak.
I am not convinced a living being exists that can resist a "no matter how long" boiling. This seems frankly absurd to me. We can discuss whether 60, or 100, or 150 minutes are sufficient, but "boiling forever" will certainly kill any spore or anything that lives IMHO.
For what I know, it's the combination of acidity and heat which prevents the danger. There is no clear-cut acidity or clear-cut heat. The more the acidity, the less the heat necessary. Less acid, more time needed. But I do believe there is a point where the spore dies, even if with no acidity at all.
This source says that 100 minutes should kill the spore, although it also says that some sources say what you say (many hours) but for that, again, I would like to see some experimental verification.
https://ucanr.edu/sites/MFPOC/Emergency/Botulism/
Regarding "storing wort after a simple boil is dangerous" I think the general belief is that you cannot store wort and then use it "as is", you have to boil it first to use it. I agree using stored wort without boiling is dangerous. I don't agree using stored wort after prolonged boiling is dangerous, if that's what you mean.
" Despite its extreme potency, botulinum toxin is easily destroyed. Heating to an internal temperature of 85°C for at least 5 minutes will decontaminate affected food or drink. "
What ultimately kills human beings is the toxin. Getting rid of the spore is useful and important if the food is going to be used again. If one drinks all the boiled wort (without using it for repitching, for instance) then destroying the toxin is enough because the spore is dangerous to the extent that it produces the toxin. On the other hand, using questionable wort to prime beer for bottling would certainly be dangerous.
As a side note, everybody in Italy used to make canned homemade tomato sauce. That has a pH of 4,6 if memory serves, but that doesn't mean that the botulinum has an easy life if boiled at pH pH 4,7, pH 5 or pH 5.4. Acidity is a factor in killing the botulinum, and the more, the better.
pH 4.6 is not a "threshold" or a "red line", because nobody would prepare canned sauce without a large safety margin. Millions of people grew up with that stuff prepared at home with all possible human mistakes and procedure imperfections.
The Ancient Romans used to eat ham and salami and that stuff is not cooked, it's consumed 6 months after preparation or later, and they did not have modern preservatives nor they had the way to inoculate the meat with lactic bacteria. Although notoriously that meat was not perfectly safe, it certainly was not deadly and was mostly safe. Salami reaches pH 5,3 or so.
I remain convinced that the acidity of wort is effective in killing the spore with sufficient heat, but remain open to any documented fact in the other direction, of course.
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You don't need to kill the spores (although it's good if you can accomplish that), you just need to keep them from sprouting. Low water availability will do that -- that's why honey doesn't spoil -- and I think that's what low pH does also.
No, it most definitely doesn't. Please stop spreading incorrect and dangerous information. From your own source:
"
5. How long does it take at rolling boil 212 F to kill Botulism spores? How many hours? There are people without access to anything except wood fires.
I do not believe this is known. As stated above even at high pressure the appropriate processing times range from 20 to 100 min depending on the food. At a rolling boil one would expect similar large variability and orders of magnitude longer times. At this point one would question the palatability of the food in question – possibly why we do not have this information. Sometimes one sees general statements that C. botulinum spores will survive 5 to 10 hours of boiling but this is meant as an example of how heat resistant the spores are and should not be interpreted as validated processing times.
"
It's also not preserved in a strictly anaerobic packaging, quite the opposite actually. The comparison is completely meaningless in the context of botulinum.
I found this reputable source regarding sterilization with a microwave
https://www.cdc.gov/infectioncontrol/guidelines/disinfection/sterilization/other-methods.html
As you see, the maximum which is considered is 5 minutes for a home-type microwave oven. Other sources indicate 1 minute sterilizes all but the most "robust" microbes.
For what is of interest to homebrewers, whose goal is normally sanitization rather than sterilization, microwave ovens are absolutely useful.
I won't bet about unicorns, though
PS This source indicates heat as the real sterilizing agent, and maybe radiation itself. For what I have read though (where? I don't know) it's really the explosion of the microbe from inside which is deadly. That should certainly include the spores of botulinum, if that mechanism is actually in place. Regardless, microwave ovens as a means of sterilization is a reality.
Many homebrewers use dried yeast from opened and re-sealed packs which is completely sealed from oxygen, self-sealed from oxygen (with one of those home machines to make vacuum) therefore not commercially canned, and won't be cooked before eating.
Your home-made beer is probably completely sealed from oxygen, won't be cooked before eating, it's not commercially canned, and it's safe to be consumed, even though it has a pH of 5 or so.
Also, it is common practice to vacum-seal cheese and consume it much after the vacuum procedure and it won't be cooked before eating.
A similar procedure is applied for home-dried food, such as bananas, tomatoes, aubergines, onions etc.
Regarding fresh food, that's also often kept in a vacuum or almost-vacuum condition (with those manual pumps) and then consumed without re-cooking it (peppers, chicory, whatever). Overall, vacuum is a valid preservative even when it's not industrially made.
For what I know, the danger of botulinum doesn't normally exist because the food hosts a host of different bacteria, not just botulinum.
What makes botulinum dangerous, in home canning, is that all other bacteria are killed, and the botulinum remains alone sitting at the table, thus creating the conditions for a huge proliferation of it. The only way in which botulinum kills is through an imperfect sterilization procedure.
If the substrate is "crowded" by other microbes, the botulinum will not have the space to expand.
Basically, a food (a substrate) is like the tube during peak hours: you cannot reproduce more than much, because you have no space, other bacteria are "crowding" the substrate and are literally occupying the place.
This is also the reason why sauercrauts, salami, ham, etc. can be safe to consume, and sauercrauts remain safe to consume row, even after many months in the fridge, because molds have a hard time trying to find a place at the table.
C. botulinum is not really "competitive" when other microbes are present. It needs an empty environment to thrive. This empty environment is, in its ideal form, an imperfectly sterilized and sealed can. There is no mortal risk of botulinum in food which did not undergo a failed attempt at sterilization. (there is a non-mortal risk with row fermented food if the substrate was not adequately prepared, that's another thread).
Our defense against botulinum is not oxygen, is all other bacteria and molds and yeasts etc. which contaminate the food much faster and much better than botulinum.
I make sauercrauts at home, I experienced 1-year old sauercrauts of chili-peppers kept in the fridge. At 9 months they were still very good, at 12 months they begun having a hint of cheese.
Your bottle of Tabasco sauce will remain good for many, many months after opening, without spoling, for the same reason I suppose (that's fermented food, if memory serves).
As a side note, industrial beers are not sterilized (only pasteurized) and many "craft beers" are not even pasteurized, yet they pose no risk of botulinum, even though their acidity is less than what appears to be considered safe by some.
With all that said, I definitely would boil old wort, and not just for botulinum, but for all the other microbes which can thrive in there!
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I found this reputable source regarding sterilization with a microwave
https://www.cdc.gov/infectioncontrol/guidelines/disinfection/sterilization/other-methods.html
As you see, the maximum which is considered is 5 minutes for a home-type microwave oven. Other sources indicate 1 minute sterilizes all but the most "robust" microbes.
For what is of interest to homebrewers, whose goal is normally sanitization rather than sterilization, microwave ovens are absolutely useful.
I won't bet about unicorns, though
PS This source indicates heat as the real sterilizing agent, and maybe radiation itself. For what I have read though (where? I don't know) it's really the explosion of the microbe from inside which is deadly. That should certainly include the spores of botulinum, if that mechanism is actually in place. Regardless, microwave ovens as a means of sterilization is a reality.
That's not what that says.
" Of concern is that home-type microwave ovens may not have even distribution of microwave energy over the entire dry device (there may be hot and cold spots on solid medical devices); hence there may be areas that are not sterilized or disinfected."
Then also:
"The use of microwave ovens to disinfect intermittent-use catheters also has been suggested. Researchers found that test bacteria (e.g., E. coli, Klebsiella pneumoniae, Candida albicans) were eliminated from red rubber catheters within 5 minutes. Microwaves used for sterilization of medical devices have not been FDA cleared. "
Botulism spores are a lot more hardy than yeast and regular bacteria, so this also doesn't indicate safety.
If you want to kill germs on your dish sponge, home microwaves are great. They shouldn't be used to "sterilize" perishable food for room temperature storage.
I found this reputable source regarding sterilization with a microwave
https://www.cdc.gov/infectioncontrol/guidelines/disinfection/sterilization/other-methods.html
As you see, the maximum which is considered is 5 minutes for a home-type microwave oven. Other sources indicate 1 minute sterilizes all but the most "robust" microbes.
For what is of interest to homebrewers, whose goal is normally sanitization rather than sterilization, microwave ovens are absolutely useful.
I won't bet about unicorns, though
PS This source indicates heat as the real sterilizing agent, and maybe radiation itself. For what I have read though (where? I don't know) it's really the explosion of the microbe from inside which is deadly. That should certainly include the spores of botulinum, if that mechanism is actually in place. Regardless, microwave ovens as a means of sterilization is a reality.
From the article, and salient to my point about unicorns:
While it is true that for most brewing sanitization is sufficent, for the case of C. botulinum (I always thought it was botulini, live and learn) sterilization is a minimum standard. Also, I may have missed it, but I didn't see where they were taking about C. botulinum in particular or even the Clostridium family in general. The only mention of it is in a process called "vapor-phase hydrogen peroxide" which I can make guesses on, but it is well outside the scope here.
The radiation source for sterilization they talk about is gamma rays from a Co-60 source. Microwaves have less energy than visible light, which has less energy than UV, which has less energy than x-rays which has less energy than gamma rays. You're talking several orders of magnitude of energy here.
Well, they talk about "sterilization" which, when reached, implies that also all bacteria of the Clostridium genus will be killed, otherwise it's not sterilization in medical terms.
It's a sufficiently good unicorn for our purposes and, if we exclude spores, it's also sufficiently good for the vast majority of laboratory works. I do presume that it is good for spores as well but that's not the central part of the message, which is "your microwave oven can be very useful for your homebrewing actitivity".
Just as another example, if for some unexpected problem I need to sanitize a bottle or two during a bottling session, I do that with the microwave: just put a glass full of water in the oven and a bottle (or two 50cl bottles) with a little water in them. 40 seconds and that's it. Don't do that with bottles which have labels which contain metallic parts (labels can use metals).
Let me be clear, there are several things that keep C. botulinum at bay. The methods that we keep them from growing, from (what I believe to be) most common to least common are: oxygen exposure, dehydration, high-acidity environment, and high-ethanol environment.
Failing that, we use heat treatment to feature the toxin.
There are probably more, but many of the products that haven't sterilized the C. botulinum listed here use one of more of those methods before they use cold.
Many products that require no refrigeration are sold in a refrigerated case because of people's perception of the product. For example, Velveeta requires no refrigeration until you open it, yet because people perceive it as cheese, they sell far less of it if they put it elsewhere in the store. Refrigerated canned ham may be the same way. That is, because it is sold refrigerated doesn't mean it requires refrigeration. Best example of this, however, is beer.
Please look at the OP. This is about canning wort. This is explicitly about not excluding spores.
Sanitization and sterilization is usually defined in terms of target species. Sterilization from, say, salmonella, an acidophile, is a very different beast from a thermophile. Assuming they are the same is asking for a trip to the hospital.
I quote a large stretch:
" The initial reports showed microwaves to be an effective microbicide. The microwaves produced by a “home-type” microwave oven (2.45 GHz) completely inactivate bacterial cultures, mycobacteria, viruses, and G. stearothermophilus spores within 60 seconds to 5 minutes depending on the challenge organism933, 935-937. Another study confirmed these resuIts but also found that higher power microwaves in the presence of water may be needed for sterilization932. Complete destruction of Mycobacterium bovis was obtained with 4 minutes of microwave exposure (600W, 2450 MHz)937. The effectiveness of microwave ovens for different sterilization and disinfection purposes should be tested and demonstrated as test conditions affect the results (e.g., presence of water, microwave power). Sterilization of metal instruments can be accomplished but requires certain precautions.926. Of concern is that home-type microwave ovens may not have even distribution of microwave energy over the entire dry device (there may be hot and cold spots on solid medical devices); hence there may be areas that are not sterilized or disinfected. The use of microwave ovens to disinfect intermittent-use catheters also has been suggested. Researchers found that test bacteria (e.g., E. coli, Klebsiella pneumoniae, Candida albicans) were eliminated from red rubber catheters within 5 minutes 931. Microwaves used for sterilization of medical devices have not been FDA cleared. "
This note quotes some different studies, which arrived largely at the same results, that is that a home-type microwave oven completely inactivates not just bacteria, but also spores (although only one genus is cited) and viruses ("initial report"). That's a lot. That's within 5 minutes. The other study confirms that but suggests water and higher energy (W) is needed than in the previous study (we don't know the wattage of the initial report.
Sterilization of metal instrument can be achieved, which is very important for laboratory work and for homebrewing.
Yes, there is a caveat with "cold spots". This requires some excess sterilization. It says "of concern" it doesn't deny the validity of the procedure.
Again, this is a tool in our toolbox. Other sterilization procedures (by alcohol, chemical substances, boiling, vapour etc.) will have their own set of pros and cons.
The message is that a microwave oven definitely provides a way to sterilize things and food, with some asterisks.
Actually in my ignorance of the subject I can hardly find another sterilization means which is so broad in scope. Chemical substances generally are effective against one subset of microbes, and the same for acids. Boiling requires a lot of effort to be sure to destroy spores, from tenths of minutes to hours depending whom you ask to. Autoclave costs, etc.
A simple and humble microwave oven, which is in every house, is reported by some scientific experiment to kill everything including spores in 5 minutes. That's what I bring home.
I should add that there is no universal form of sterilization. The medical definition of sterile probably has a very specific definition in terms of how many of a particular type of organism can exist.
Until today I thought that the broad definition applied, as in here:
https://en.wikipedia.org/wiki/Sterilization_(microbiology)
I understand that sterilization from salmonella requires different sterilizing agents than a sterilization against a thermophile etc. But for what I know, if something is "sterile" this means there is nothing in it that can reproduce itself, whatever it is.
I understand the OP wants to can wort, but I dont' understand whether he wants to use it "as is" after opening the can or he wants to boil it.
I agree with you that using the canned wort "as is" would be a Russian roulette. But as we saw a few minutes of boiling will clear the risk of botulinum. That might make the goal of the OP feasible.
That is very much not what this article is saying, especially since it talks about Clostridium species elsewhere in the article. If you're worried about G. stearothermophilus spores, then you're good, but this is about C. botulinum.
This was my proposal in #46.
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