Can I avoid botulism by opening the bag while cooking sous side?

[torolover]

I understand Botulism can develop after long sous vide cooking under vacuum sealed bags.  I understand the quick chill method and making sure fridge is cold, but I'm wondering about...

 

1.  If I don't vacuum seal the bag and seal it with water displacement method, can Botulism still develop?

 

2.  If I purposely leave a little air in the bag, can Botulism still develop?

 

3.  If I open up the bag from time to time to let oxygen in DURING the sous vide cooking, can Botulism still develop?

Edited December 30, 2014 by torolover (log)

[Shalmanese]

Botulism is a problem for storage, not cooking. If you're eating the food immediately after cooking, there are no botulism worries. The risk of botulism has to be weighed against the significant benefits of storing under vacuum. You can always decant sous vide cooked foods into standard containers before storage but you now have problems with oxidation and contamination from spoilage and pathogenic organisms in the transfer.

If you're storing sous vide foods for under a week in the fridge, there's no need to worry about botulism or any other bugs as long as your food is properly pasteurized. Even beyond that, botulism grows extremely slowly, if at all at fridge temperatures. For the most part, for the home cook, I can't see too many instances where you would need a more than a week of storage. The concerns about botulism are more for commercial food prep where shelf life is a concern.

[gfweb]

Long low temp SV cooks might have a chance for the bug to grow.  I forget the magic temp...(130F or so?) above which this isn't a concern.

[Martin Fisher]

Clostridium Botulinum  (type E and other non-proteolytic strains)

Temperature range for growth = 38° to 113°F (3.3° to 45°C)

 

(Source:Hauschild, A.H.W. 1989. Clostridium botulinum. In Foodborne Bacterial Pathogens. Doyle, M.P., ed., Marcel Dekker, Inc., New York,

NY. )

[Matt L]

Sous vide is perfectly safe at normal cooking and storing temperatures. The go to text if in any doubt is Douglas Baldwin's which is very clear on both cooking and storing temperatures for safety. http://www.douglasbaldwin.com/sous-vide.html#Safety_Summary

Edited December 30, 2014 by Matt L (log)

[dcarch]

Not an expert, just some questions:

 

1. Is it true that Clostridium Botulinum can grow in any environment, including vacuum. But you don't need vacuum to promote botulinum growth?

 

2. Isn't it true that using a Foodsaver type machine to bag food doesn't really give you true vacuum (14 lbs/sq in atmospheric pressure in vacuum)? Airless and vacuum are two different conditions.

 

dcarch

[gfweb]

It requires an oxygenless environment to grow.  An evacuated food saver bag will suffice.

[torolover]

Thanks for the tips everyone!  I think I understand the safety of sous vide food and how to store it safely.

 

I'm asking in theory.  I thought Botulism has to be in an oxygen fee environment? If so:

 

1.  If there is a little air in my zip lock bag, do I still have to worry about Botulism?

 

2.  If I open the bag periodically while the meat is sous vide, do I still have to worry about Botulism?

Edited December 30, 2014 by torolover (log)

[Martin Fisher]

Botulism is a disease, if you asking if C. Botulinum can grow and produce toxins in the in a Ziploc bag...the answer is possibly if conditions are right. Folks have gotten botulism from baked potatoes wrapped in foil that were left at unsafe temperatures.

So, it's obviously very important to maintain safe times and temperatures.

[pbear]

Unfortunately, I didn't save the link, but I recall reading in the last year some authoritative source which explained that air isn't an adequate control for botulism because it's able to tolerate a small amount of oxygen.  Anyhoo, there's really no question as to the answer.  Home canned goods are a common cause of the few cases of botulism poisoning we see each year.  In each of those cases, there was air at the top of the jar after processing.

[gfweb]

The bug isn't going to grow in an open container. The less oxygen, the better for the bug.  Other aerobic bacteria can help out by consuming O2 and reducing the environment so anaerobes can grow in closed but not airless containers.

 

  A far better precaution is controlling the temperature..keep it cold or keep it hot. Then you need not worry about how much O2 is there and whether Clostridia can grow.

[Shalmanese]

Botulism can be prevented from growing if any of the following are true:

 

• Environment is aerobic
• pH is below 4.6
• Temperature is below 3C/48F
• Water activity is below 0.95

source.

[Matt L]

Thanks for the tips everyone! I think I understand the safety of sous vide food and how to store it safely.

I'm asking in theory. I thought Botulism has to be in an oxygen fee environment? If so:

1. If there is a little air in my zip lock bag, do I still have to worry about Botulism?

2. If I open the bag periodically while the meat is sous vide, do I still have to worry about Botulism?

Are you talking about in-cook or during storage?

If it's in-cook and your temperature range is above the danger zone, botulism will be killed whether or not there is oxygen in the bag (although the spores will still be there). Opening the bag won't add anything bar perhaps risking your cook temp going astray as you add air into your bag. Opening the bag won't kill any spores that are there.

If you rapidly chill and refrigerate at an appropriate temperature, then new pathogens won't grow at any rate that would cause concern, whether or not you open the bag. Opening the bag would only increase oxidation spoilage of your food, which I guess you'd want to avoid. Again botulism isn't a risk so bag opening is pointless.

If you cook and then leave at room temperature for a significant time to cool/store, perhaps opening the bag might reduce your botulism risk, but you're going to be looking at a whole mass of other food pathogen growth over time anyway - sous vide is about pasteurization not sterilization.

Tldr: opening the bag is pointless if you follow good food safety protocols. If you don't, it's not just botulism you'll be worrying about.

Edited December 31, 2014 by Matt L (log)

[torolover]

Wow great info, thanks for all your help!  I have another question regarding reheating and the danger zone temp.

 

I often sous vide a large batch of meat on Sunday and keep the meat in a cold fridge.

 

On weekday mornings I prepare my lunch with these sous vide meats.  I usually cook fried rice and mix the sous vide meat into it.  I prepare my lunch at 7am, and get to the office at 9am.  Once I get to the office I put my lukewarm lunch into the fridge.  

 

Then at 1pm I reheat my lunch in the microwave.

 

Am I safe to eat the lunch with the sous vide meat? It's probably been in that danger zone for 4 hours?  What is the cut off time for eating safely when it's been in the danger zone temp?

Edited December 31, 2014 by torolover (log)

[gfweb]

If the meat is kept sealed in its sv bag and was cooked at a pasteurizing temp it will be safe until the bag is opened. At that point it can begin to grow whatever might've been introduced when the bag was opened.

 

Easy solution is to do separate SV bags of meat for each day.

 

How dangerous is the current method?   Certainly you are alive and well, so the odds of food poisoning would seem to be low.  But low probability things still happen given enough time.

[Shalmanese]

Wow great info, thanks for all your help!  I have another question regarding reheating and the danger zone temp.

 

I often sous vide a large batch of meat on Sunday and keep the meat in a cold fridge.

 

On weekday mornings I prepare my lunch with these sous vide meats.  I usually cook fried rice and mix the sous vide meat into it.  I prepare my lunch at 7am, and get to the office at 9am.  Once I get to the office I put my lukewarm lunch into the fridge.  

 

Then at 1pm I reheat my lunch in the microwave.

 

Am I safe to eat the lunch with the sous vide meat? It's probably been in that danger zone for 4 hours?  What is the cut off time for eating safely when it's been in the danger zone temp?

 

 

Bugs are not sitting around with tiny stop watches impatiently waiting for the magical 4 hour mark before shouting out "Yippee! Let's kill all the folk!". The 4 hour mark is the worst case guideline for if you handle food inappropriately every step along the way.

 

Your food is absolutely fine to eat. You're taking more years off your life obsessively worrying about food safety than from dangerous food. I mentioned in another thread that you're at least an order of magnitude more likely to die from a fatal car crash on the way to buy your groceries than from botulism in your food. 

[gfweb]

 

 

. I mentioned in another thread that you're at least an order of magnitude more likely to die from a fatal car crash on the way to buy your groceries than from botulism in your food. 

 

True enough.

Certainly much more than an order of magnitude...more like 5 or 6, I'd bet.

 

But botulism isn't the only food poisoning and who wants to get sick if a little good technique will prevent it?

 

[pbear]

Right.  For example, the main concern with fried rice isn't botulism but rather bacillus cereus.  Four hours is probably okay, but there's a non-zero risk.  How the rice is cooked and stored before preparing each day's meal is more important than the sous vided meat.

[torolover]

What about dangers of sous vide a whole roast like Boston Butt?  My plan is to sous vide a whole Boston Butt at 150F for 24 hours then quick chill and keep in fridge.   I'll take out the next day and reheat in oven at 300F until center reaches 130F,  then blast at 500F for 10 min to get a crust.

 

For Botulism, the meat will probably be between 50F to 120F for more then 10 hours in total!  Probably will take more then 4 hours to reach 150F and then when I quick chill, another 4 hours to reach 40F.  When I reheat probably another 1 hour to reach 120F.    I assume internal meat is sterile, so I'm only concerned about the Botulism.

 

Any thoughts?  I want to use the whole Boston Butt and not slice it thinner because it's for a party.

Edited January 1, 2015 by torolover (log)

[gfweb]

I'm not sure about the length of time to reach 120F, sounds very long to me.

 

Factors to consider...

 

If present, Botulism spores won't be deep in the meat, they'll be on top of it more or less, so they will get hot very quickly....in minutes to reach 120 in the SV bag.

 

As long as the SVd bag remains sealed after cooking, the chilling and the second cook in the oven will be of an already pasteurized butt...and therefore no risk.

 

According to the CDC there were fewer than 200 cases of botulism in 2012 and many of those were from home-canned and stored foods. I saw no mention of a sous vide-related case  http://www.cdc.gov/nationalsurveillance/PDFs/Botulism_CSTE_2012.pdf  

[Shalmanese]

What about dangers of sous vide a whole roast like Boston Butt?  My plan is to sous vide a whole Boston Butt at 150F for 24 hours then quick chill and keep in fridge.   I'll take out the next day and reheat in oven at 300F until center reaches 130F,  then blast at 500F for 10 min to get a crust.

 

For Botulism, the meat will probably be between 50F to 120F for more then 10 hours in total!  Probably will take more then 4 hours to reach 150F and then when I quick chill, another 4 hours to reach 40F.  When I reheat probably another 1 hour to reach 120F.    I assume internal meat is sterile, so I'm only concerned about the Botulism.

 

Any thoughts?  I want to use the whole Boston Butt and not slice it thinner because it's for a party.

I'd be far more worried about spoilage bacteria potentially getting into a crevice in the meat and causing off flavors.

I don't get why you would reheat in a 300F oven. By the time the inside is warm, the outside's going to be overcooked, like if you had just done it in the oven conventionally. Why not just start the sous vide a few hours later so you can go straight from the bath to the oven?

[torolover]

I'd be far more worried about spoilage bacteria potentially getting into a crevice in the meat and causing off flavors.

I don't get why you would reheat in a 300F oven. By the time the inside is warm, the outside's going to be overcooked, like if you had just done it in the oven conventionally. Why not just start the sous vide a few hours later so you can go straight from the bath to the oven?

There are 2 reasons I would reheat in oven instead of sous vide before blasting in a 500F oven.

 

1.  If I sous vide first, it would take 4 hours or more to get center to 130F.  That would add another 4 or more hours to the danger zone.  It's probably already been in danger zone for 8 hours when I sous vide the day before.  

 

2.  If I put in oven at 250F-300F, it would dry out the surface to get a good crust before I blast it at 500F.  True the meat at surface would probably be 140F or so, but it probably isn't a big deal since the meat will already be falling apart from the long sous vide braise.

 

So you think I should just sous vide again and blast at 500F oven?

 

Am I'm too cautious about the safety for danger zone temps?

[gfweb]

I'm not sure about the length of time to reach 120F, sounds very long to me.

 

Factors to consider...

 

If present, Botulism spores won't be deep in the meat, they'll be on top of it more or less, so they will get hot very quickly....in minutes to reach 120 in the SV bag.

 

As long as the SVd bag remains sealed after cooking, the chilling and the second cook in the oven will be of an already pasteurized butt...and therefore no risk.

 

According to the CDC there were fewer than 200 cases of botulism in 2012 and many of those were from home-canned and stored foods. I saw no mention of a sous vide-related case  http://www.cdc.gov/nationalsurveillance/PDFs/Botulism_CSTE_2012.pdf