Sous Vide sous vide safety?

Hello all,

I'm a home cook trying to branch out and I've recently bought an anova sous vide (800w bluetooth model) to try and enjoy. The biggest concern I have is about how to avoid botulism. Ive read through the forums here and in other places, but I seem to be finding answers more vague than I'd like.

As far as I understand, you can take refrigerated or even frozen meats, place them in your airless bag of choice, be it vacuum or ziploc, and let it cook for the recommended times and temps. This pasteurizes the food, kiling the bacteria.

From there, the process seems to muddy. I havent found a definitive answer on how long foods can be left out, if it matters if the food is still in the bag, or if it matters that you've seared the food after cooking sous vide.

For example, if I have prepared steak or chicken this way for my family, removed it from the bag and seared it, and then eaten and had a chat, is this meat still ok to be put into the fridge after 30 minutes or an hour and rewarmed tomorrow or will I have served someone death for lunch the next day?

Im sure that's an exaggeration, but theres no real process detailed anywhere ive seen. If someone could give me a casual home cooks process on how to safely sous vide and take care of any food left over, I would appreciate it.

So after youre done cooking your meat, youre going to either want to use it right away or put the bag in an ice bath to cool it down. If youve opened the bag but have left overs, let the meat cool down, and then vacuum seal it again and store it in the fridge .

But i wouldnt just let a bag of cooked protein sit out at room temp for an extended period of time. Note that there is a temperature window in which bacteria thrives the most, between about 40 degrees F and 130 F. Hot foods above 130, and cold foods below 40. The goal of icing down hot food is to bring it through this "danger zone" as quickly as possible, so it can be stored cold. If you were to take a piping hot bag of protein, and just stuck it in your fridge, or left it on the counter, it is going to spend quite some time, in the danger zone, allowing ample time for bacteria growth, before it gets down to cold storage level temp. This is how temperature related food poisoning works. I hope this helps.

You realise that sous vide is probably safer than grilled? In most circumstances you would have pasteurized the meat (aka killed most of the bacteria). Grilling you typically don't take the meat to the right temp or hold for the right time to pasteurize.

So the simple question. Would you normally do it?

Pasteurizing is time AND temp dependant. And 130F is well and truly above the growth temp for most bacteria. You are pasturizing at that temp (but it takes an hour or more at that temp for that to happen).

My understanding is that ice baths are used more to stop cooking than bacteria growth. I'll add more later

Do you usually prepare your meat and then wait for an hour before you eat it? I do not see any difference between sous vide and other cooking methods. Like Chef_ said: if you will leave your meat on room temp for extended period of time it really does not matter how you prepared it.

krx927 said:

Do you usually prepare your meat and then wait for an hour before you eat it? I do not see any difference between sous vide and other cooking methods. Like Chef_ said: if you will leave your meat on room temp for extended period of time it really does not matter how you prepared it.

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This is what I was thinking when I read the OP.

I agree with other posters. Dont over think or overcomplicate. Cooking souvide is no different than any other methods. The only difference is maintaining constant temperatures. Once its done cooking and out of the bag, you treat it like any other foods you cook. This includes methods for leftover storage.

Don't leave food out for too long at room temp. Throw leftovers in the fridge. Eat it before it starts to smell bad.

Thank you all for the quick replies. I was hoping that I was making the issue was larger than it was.

For clarification, I wasn't referring to waiting an hour to eat cooked foods, I was using an hour as an extreme amount of time after cooking to put the food away, such as after eating and if having a nice dinner chat runs long. I don't usually leave food out even close to that amount of time, I was mostly just seeing where those boundaries could be pushed, hypothetically.

That being said, I'm glad that I can treat sous vide foods in the same ways as other foods and be safe. Thanks again guys.

hate to disagree but you do indeed have additional worries with sous vide non aerobic bacteria are very real, botulism is bad . some general rules ( where i live to use it in the restaurant i had to write HACCP plans for each item cooked)

1. start with good product 2. keep it cold, go into the bag cold and keep cold untill cooking. if not using it after coming out of circulator ice bath immediately. dont over crowd the water basin make sure you have even heat distribution. there is a lot more to pasteurization and without knowing when a core temp is reached and held for x amount of time ( most red meat temps are to low to pasteurize even if you left it for a long..long time) i would never factor this into the equation for safe habbits. just be clean when you do it and you should be a.ok. there are also other methods in which you can dump ur sealed bags into boiling water for 12sec or so to kill surface bacteria, chill, and then cook at specific temp. there is a lot of good reading out there now a days hell you can go celeberity chef root if you want and pick up thomas kellers under pressure book, some good general saftey tips in there.

Common sense is key and remember seafood is eaten is within the unpasteurized zone. Unless you cook your seafood to 160 internal. I love SV cooking but your going to want to master the basics first and understanding hygiene and food prep best practices is the foundation of safe meals.

Writing a HACCP for SV must have been brutal.

Wdestate said:

hate to disagree but you do indeed have additional worries with sous vide non aerobic bacteria are very real, botulism is bad . some general rules ( where i live to use it in the restaurant i had to write HACCP plans for each item cooked)

1. start with good product 2. keep it cold, go into the bag cold and keep cold untill cooking. if not using it after coming out of circulator ice bath immediately. dont over crowd the water basin make sure you have even heat distribution. there is a lot more to pasteurization and without knowing when a core temp is reached and held for x amount of time ( most red meat temps are to low to pasteurize even if you left it for a long..long time) i would never factor this into the equation for safe habbits. just be clean when you do it and you should be a.ok. there are also other methods in which you can dump ur sealed bags into boiling water for 12sec or so to kill surface bacteria, chill, and then cook at specific temp. there is a lot of good reading out there now a days hell you can go celeberity chef root if you want and pick up thomas kellers under pressure book, some good general saftey tips in there.

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Wdestate said:

hate to disagree but you do indeed have additional worries with sous vide non aerobic bacteria are very real, botulism is bad . some general rules ( where i live to use it in the restaurant i had to write HACCP plans for each item cooked)

1. start with good product 2. keep it cold, go into the bag cold and keep cold untill cooking. if not using it after coming out of circulator ice bath immediately. dont over crowd the water basin make sure you have even heat distribution. there is a lot more to pasteurization and without knowing when a core temp is reached and held for x amount of time ( most red meat temps are to low to pasteurize even if you left it for a long..long time) i would never factor this into the equation for safe habbits. just be clean when you do it and you should be a.ok. there are also other methods in which you can dump ur sealed bags into boiling water for 12sec or so to kill surface bacteria, chill, and then cook at specific temp. there is a lot of good reading out there now a days hell you can go celeberity chef root if you want and pick up thomas kellers under pressure book, some good general saftey tips in there.

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Can you provide any references to why what you say is a significant risk as opposed to restaurant food health safety requirements which aim at reducing risk to zero (which isnt possible with any of this, unless yoi serve charcoaled meat, and even then still a risk).

And your comment about red meat temps is just too low is just plain wrong... first quick thing I could find (and I know it actually starts lower.).

https://www.google.com/search?site=...ization+time+temp+curve&imgrc=Mqh0e5tjUi2OnM:

Most aerobic bacteria we are worried about stop growing at around 40C and start to get killed somewhere over 50C.

You understand that the sear or drop into boiling water is doing mostlt the same as holding at 54C for 90 min. (Note we are talking temp in the middle so if you are aiming for full pasteurization extra has to be allowed for this (there is plenty of research on it if you google).

And if you are worried about surface bacteria, and non-aerobic bacteria infecting surfaces, clean surfaces and hands just prior to handling meat, and be efficient. Work quickly and seal and refrigerate, freezer or cook almost straight away.

https://www.google.com.au/url?sa=t&...gg2MAI&usg=AFQjCNHG3cXqBkrB4dR0reaInpg76ZT2DA

Finally regarding botulism, see above provides some advice, or don't pull a full vacuum and therefore prevent the creation of non-aerobic conditions which has its own drawbacks.

So in summary yes these things are a risk but key word there is risk. There are many ways to reduce that risk and anecdotal evidence would suggest the risk with sous vide is low, when you follow conventional kitchen cleanliness and procedure.

Now of course professional have to take this risk a lot more serious as they have significant legal implications for them, that however doesn't what the actual risk occurrence is.

My finally summary is, yes wdestate is sort of right, there are some potential additional worries but to put it in perspective you are probably several order of magnitudes higher (read 10, 100 or 1000) more likely to seriously hurt yourself walking up or down the 3 steps at the front of your house than to catch something while cooking sous vide.

Do some reading, Baldwin (ref in the health doc i posted) has some great info on it. Plus use Google scholar of you are inclined there is quite a bit of research out there on sous vide cooking.

I'll add a disclaimer that I am by no means an expert I probably fit into the "I have just enough knowledge to be dangerous" category.

I'll also say I tend to adopt a risk based view about things. Aka likelihood vs consequence. Some people are naturally more conservative about certain topics, like this and others (professionals) have to be because of rules and regs.

malexthekid said:

Can you provide any references to why what you say is a significant risk as opposed to restaurant food health safety requirements which aim at reducing risk to zero (which isnt possible with any of this, unless yoi serve charcoaled meat, and even then still a risk).

And your comment about red meat temps is just too low is just plain wrong... first quick thing I could find (and I know it actually starts lower.).

https://www.google.com/search?site=...ization+time+temp+curve&imgrc=Mqh0e5tjUi2OnM:

Most aerobic bacteria we are worried about stop growing at around 40C and start to get killed somewhere over 50C.

You understand that the sear or drop into boiling water is doing mostlt the same as holding at 54C for 90 min. (Note we are talking temp in the middle so if you are aiming for full pasteurization extra has to be allowed for this (there is plenty of research on it if you google).

And if you are worried about surface bacteria, and non-aerobic bacteria infecting surfaces, clean surfaces and hands just prior to handling meat, and be efficient. Work quickly and seal and refrigerate, freezer or cook almost straight away.

https://www.google.com.au/url?sa=t&...gg2MAI&usg=AFQjCNHG3cXqBkrB4dR0reaInpg76ZT2DA

Finally regarding botulism, see above provides some advice, or don't pull a full vacuum and therefore prevent the creation of non-aerobic conditions which has its own drawbacks.

So in summary yes these things are a risk but key word there is risk. There are many ways to reduce that risk and anecdotal evidence would suggest the risk with sous vide is low, when you follow conventional kitchen cleanliness and procedure.

Now of course professional have to take this risk a lot more serious as they have significant legal implications for them, that however doesn't what the actual risk occurrence is.

My finally summary is, yes wdestate is sort of right, there are some potential additional worries but to put it in perspective you are probably several order of magnitudes higher (read 10, 100 or 1000) more likely to seriously hurt yourself walking up or down the 3 steps at the front of your house than to catch something while cooking sous vide.

Do some reading, Baldwin (ref in the health doc i posted) has some great info on it. Plus use Google scholar of you are inclined there is quite a bit of research out there on sous vide cooking.

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you are also correct, however i was just shining the light on the fact that there is very real factors involved in it, as a professional cook serving the public i always strive for "reducing risk to zero". a proper MR on beef for my books is 53C (that's what i have been doing for years ) and i do my rares to 49C, that being said perhaps 49C does have a pasteurization temperature but i have never found one in my references. Also just pointing out unless you temp something while cooking you dont know when the internal temp was reached for pasteurization and are most likely going off guestimation timers

I think its important to point out proper procedure is the most important thing to sous vide safety especially with people beginning tg learn it, temperature is important both in start of the process and the end, clean habbits are important, knowing what can cause issues is important. i do agree that spending a little time reading on the subject will answer a lot of your questions.

and Mucho, yes HACCP for sous vide is very, very brutal. each item needs its own flow chart, temperature and procedure. a white/chalk board must be kept next to the sous vide bath and the refrigerator with a temp/time log and be signed hourly by an employee monitoring, yay Massachusetts laws. luckily they are starting to put out new equipment like combi ovens that have pre programmed settings for different items in them that the state accepts as legit.

Wdestate said:

you are also correct, however i was just shining the light on the fact that there is very real factors involved in it, as a professional cook serving the public i always strive for "reducing risk to zero". a proper MR on beef for my books is 53C (that's what i have been doing for years ) and i do my rares to 49C, that being said perhaps 49C does have a pasteurization temperature but i have never found one in my references. Also just pointing out unless you temp something while cooking you dont know when the internal temp was reached for pasteurization and are most likely going off guestimation timers

I think its important to point out proper procedure is the most important thing to sous vide safety especially with people beginning tg learn it, temperature is important both in start of the process and the end, clean habbits are important, knowing what can cause issues is important. i do agree that spending a little time reading on the subject will answer a lot of your questions.

and Mucho, yes HACCP for sous vide is very, very brutal. each item needs its own flow chart, temperature and procedure. a white/chalk board must be kept next to the sous vide bath and the refrigerator with a temp/time log and be signed hourly by an employee monitoring, yay Massachusetts laws. luckily they are starting to put out new equipment like combi ovens that have pre programmed settings for different items in them that the state accepts as legit.

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Totally get what your saying, and totally understand the risk approach you have to take in your profession. Though I will give you a nice new term, since you can't reduce the risk to zero, especially with this. What you are practicing is ALARP (as low as reasonably practicable) which is consistent with best practice and how health tends to manage risk.

I just like to offer the counter point cause I know when general populations hear words like botulism and salmonella they freak out.

Heck from the research I did there seems to be am average of like 100ish cases of illness from botulism a year.... quite low when you think of the number of meals (from foods where there is a reasonable risk). And I'd take a punt that a large portion of those cases are from process plants where the ALARP principle still leaves a small chance of contamination prior to the vacuum (canned or sealed), purely due to their nature. I can only imagine how much of a PIA it would be to try keep process equipment dealing with food sterilized while still usable for food.

According to the CDC, there are an average of 145 cases of botulism in the US per year. Of those, only 15% are foodborne. The majority of the foodborne cases are from improper home canning. Less than 5% of all botulism cases are terminal. The numbers say you are pretty safe from foodborne botulism and almost invulnerable if you don't eat home canned food.

dwalker said:

According to the CDC, there are an average of 145 cases of botulism in the US per year. Of those, only 15% are foodborne. The majority of the foodborne cases are from improper home canning. Less than 5% of all botulism cases are terminal. The numbers say you are pretty safe from foodborne botulism and almost invulnerable if you don't eat home canned food.

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There we go.. was right about canning just wrong about it being pro vs home

FWIW, we apparently get about one case per year in Australia (around 25 million population). I've personally never seen a patient with botulism.

Thank you guys, youve all presented some really good information and help, and ill definitely read more thoroughly. Can I, as a general take away, say that if im cooking to save for later, ice bath immediately for 1/2 hour and refrigerate, and cooking to consume, treat with normal health and safety guidelines?

I would suggest you should be fine with that... personally I don't know if I would ice bath, probably just straight in the fridge given fridge temps aren't much higher than an ice bath would be, unless you are using a lot of ice. And what effect the 1 or 2 degree difference in temp would have for anything thicker than minute steak.

But thats my personal opinion/preference.

That's the thing you don't want to do - cook SV for serving later and cool it on the counter or in the fridge. The temperature isn't the only variable: air is a lousy heat transfer medium while water is a great one, which is a big part of why sous vide (and steam ovens, and pressure cookers) work. So an object (and remember, most food is mostly water so the specific heat capacity isn't far off) coming out at 145F into water at 32F will cool much more quickly than putting it into still air at 32F. The melting of the ice keeps the food from raising the water temperature, which is why it should be water with a lot of ice and not just, say, water at 35F, unless the bath were comparatively very large.

Serving SV meat immediately (after finishing) is essentially like meat cooked any other way in terms of how long it can stay out of refrigeration. The problem with cooling it in air to reheat later is that bacteria grow exponentially faster at higher temperatures up to the temperature at which they start to die off; as it enters the danger zone it spends a fair bit of time at the high end. Then when you reheat it, 1) it will have gone through an additional cycle down and up through the danger zone, so by the time it's served it will already have an hour or more on its clock as opposed to something like 15 minutes, and 2) you might not be reheating it through to a bacteria-killing internal temperature.

So yes, floggindave, that is correct for the takeaway, and the ice bath is important.

Except there is "no" bacteria to grow....

Afterall most most bacteria was killed by the pasteurization process... and then other stuff, like botulism, grows in higher temps like 40 to 50C plus. Which even with lousy specific heat transfer properties it won't take long for the meat to pass out of (if botulism is even an issue, which we have already discussed is highly unlikely.

Now leaving out is a different issue. As your temps, typically are within bacterial growth zones. So the percent or two that didn't get killed during pasteurization are able to readily propagate to nasty levels...

Statements like that are what I put in the category of knowing just enough to be dangerous. Because yes you are right about the heat transfer but what is the impact of the different time take, how quickly does the bacteria propagate etc.

Given I use the fridge instead of ice water, anecdotal evidence suggests that good hygiene within preparation may actually be a much larger player.

Like I said earlier, don't listen to me or anyone on here as god except for using it to add to knowledge base (unless someone here has done a PhD on bacteria and pathogen growth during sous vide cooking). Go read lots. Lots and lots there is a wealth of knowledge on these topics within scientific areas. And form your own practices based on that and what works for you.

Sorry should also say GorillaGrunt. Not saying you are wrong but just that I think we are all right to varying degrees. The key is what are important things to do and are musts and what are the "best practice" that may not be necessary for a home cook doing this once a week as opposed to 30 times a day

Quoting from USDA food safety guidelines for consumers at https://www.fsis.usda.gov/wps/porta...food-handling/danger-zone-40-f-140-f/CT_Index :

"One of the most common causes of foodborne illness is improper cooling of cooked foods. Bacteria can be reintroduced to food after it is safely cooked."

That said, this subject can get very complicated and the rules for commercial kitchens are designed for a simple one-size-fits-all approach, to wit, follow these rigidly and risk is minimized across the board without having to do research or put more thought into it, and only quick and easy measurements are required. Personally I would always recommend using an ice bath for sous vide food to be served later. However, for instance, stock is supposed to be cooled in ice too for the same reason -- it takes too long to cool in air -- and I rarely do that at home. It's probably different with a gallon or two of stock that will always be boiled before serving as opposed to the much larger quantity that you'd find at a restaurant, but the point is that I don't know enough to conclusively state that it's safe to do it that way with that material, that equipment, that quantity, etc. so I don't know how much risk I'm exposing someone else to if I advise them to skip a step.