Chicken Stock Safety

[StanSherman]

I don't know if that's good advice....boiling will surely kill the bacteria, but won't do anything to the toxins they may leave behind. I wouldn't go around preaching that type of behavior...

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Before pressure canning, that was a proper technique for food preservation. From what I understand after the first boil spores can then "hatch" a couple days later. The second and third boil get rid of the spores.

Since we pressure can large batches I'm not sure of the time intervals necessary for chicken stock.

[torolover]

I often sous vide 5 pounds of chicken thighs for 8 hours at 156F.  There is a lot of chicken juice and fat left over in the bag.

 

I plan to save all the juices and fat every time I sous vide until I get about 4 cups of chicken juice.  Then I can make chicken soup and use the fat for frying veggies.  This may take me a month of saving juices however.  Is storing the juices and fat for a month or longer safe?

 

If I empty all the juices and fat from the bags, and boil them, will this be safe to store for long periods in fridge or freezer?  I am also concerned about Botulism Spores which I understand is heat resistant.

 

Thanks!

 

 

 

 

Edited January 31, 2016 by Smithy
Added tag (log)

[pastrygirl]

If the chicken is safe to eat, why wouldn't the juices be?  Maybe I'm missing something but I don't see any problem with saving the liquid in the freezer.   Wouldn't keep it in the fridge for long, there are other things besides botulism that would make it go bad. 

[gfweb]

The issue is storage. Neither SV nor boiling kill botulism spores.  If you use immediately, or after a short period of refrigeration, the spores won't have time to grow.  Long storage, even in the fridge, opens the possibility of spoilage.

 

So freeze what you can't use immediately.

[btbyrd]

If I could manage to save it, I'd just freeze it. I have a ton of vac bagged stocks in my freezer, and they're safe for basically forever (provided that you chilled them properly). But SV jus is something I always intend to save, but just end up using immediately. The best thing to do is move it directly from the bag to a pot and bring to a simmer or light boil for several minutes. This will cause many of the proteins to coagulate together and form a raftlike scum you can try to fish out and strain (cheesecloth works best). Chill and defat it. If this all works out correctly, you'll end up with clarified (or semi-clarified) jus that's incredibly flavorful and ripe for saucework or glazing.

 

For sauces:

Steep some herbs in the warm jus for 10 minutes and strain again. 

Mount it with a fat of your choice (tallow or butter for beef jus, butter or bacon fat for pork, butter or duck or schmaltz for chicken).

Salt to taste

Finish with an acid of your choice. Or maybe some sherry, white, or cognac. 

 

For glazes: Use clarified, salted, jus to glaze panroasted vegetables or potatoes. Feel free to mix it with other things you've got around the place -- soy sauce, fish sauce, chili sauce, whatever -- and throw on whatever you want to.

 

If, for some reason, you cannot find an immediate application for your clarified SV bag jus, chill and transfer it to a freezer bag (vacuum or otherwise), and freeze it until you need it. But I find I rarely have a storage problem.

Edited January 31, 2016 by btbyrd (log)

[Anna N]

btbyrd,

 Many thanks for this.   I have printed it out for future reference.

[DocDougherty]

I sous vide turkey thighs for 24 hr @ 165°F, then chill and hold in the refrigerator. There isn't much juice when a single thigh is de-bagged so it winds up in soup or sauce within a day or two.  But if you are doing a lot of chickenthighs perhaps the best approach is to understand what botulism spores demand and what it takes to denature the toxin:

C. botulinum spores can be killed by heating to extreme temperature (120 degrees Celsius) under pressure using an autoclave or a pressure cooker at for at least 30 minutes. The toxin itself can be killed by boiling for 10 minutes.

So eat the thighs quickly, and freeze the juice until you have enough to make soup. Then pressure cook the juice for 30 min if you are concerned, or simmer it for 10 min even if you are not, before you make your soup.  I find that the long cooking time facilitates the liquid in the bag dissolving a large fraction of the connective tissue, though not all.  However, after a few careful dissections you become quite familiar with the anatomy of the bird and can disassemble the pieces into bone, fat, residual connective tissue, and mouth watering tender flesh. If you have enough residual fat you can shred it and make confit. Or torch it and top a salad or soup or put it in a taco or burrito or make an omelet or a souffle, or just put it into the soup.

[EnriqueB]

You don't need to sterilize for botulinum spores for safe storage, which are the treatments that are being suggested here. A heat treatment of 90ºC/10 min is considered enough for fridge storage of food under vacuum below 8ºC(http://acmsf.food.gov.uk/sites/default/files/mnt/drupal_data/sources/files/multimedia/pdfs/acm777annex.pdf). And the juices will not be under vacuum after the initial SV cooking, so it would be even safer. So just boil the juices for 10 minutes, make them cold fast and keep in the fridge as cold as possible. But take into account that with that treatment spoilage will arrive earlier than any botulism hazard, so in any case I suggest you freeze the juices after boiling them.

[Shel_B]

I made a batch of chicken stock in the Instant Pot yesterday, got distracted, and left it sitting in the pot overnight. This morning I cleaned and drained the stock, put it into storge containers and then into the fridge.

 

Since the stock was left out at room temp for so long, do I need to be concerned about bacteria growth, botulism, or whatever can happen to stock left uncooled and unrefrigerated for 8 hours or so? Would reheating it and bringing it to a boil reduce or eliminate any such problems?

[FauxPas]

33 minutes ago, Shel_B said:

Since the stock was left out at room temp for so long, do I need to be concerned about bacteria growth, botulism, or whatever can happen to stock left uncooled and unrefrigerated for 8 hours or so? Would reheating it and bringing it to a boil reduce or eliminate any such problems?

 

Here's a good NT Times article on this:

 

https://www.nytimes.com/2011/08/24/dining/bending-the-rules-on-bacteria-and-food-safety.html?unlocked_article_code=1.ME4.IGb8.fLq2UZcE6q4B&smid=url-share

 

Edited to add: I chose to throw out poultry stock after forgetting it overnight! Maybe I was being overcautious and maybe boiling for at least 10 minutes would have been sufficient, but I tend to worry about food safety.

 

I usually put the pot in the sink with ice water to help cool it faster or put into smaller containers, etc. 

Edited September 20 by FauxPas (log)

[Shel_B]

Thanks for linking the article.  Based on the article and my own experiences, I'll not be concerned about the safety of this batch of stock.

 

The article did mention flavor degradation as a possible side effect of leaving the stock/sauce/etc. out too long and then reheating.  A test of that idea may be worthwhile.

Edited September 20 by Shel_B
typo (log)

[gfweb]

Although some food safety rules would have a problem with the stock, if it stayed sealed in the IP it should be fine.

 

Even moreso if it was cooked for >15 minutes at pressure cooker temps which is the equivalent of an autoclave.

[Shel_B]

54 minutes ago, gfweb said:

Although some food safety rules would have a problem with the stock, if it stayed sealed in the IP it should be fine.

 

Even moreso if it was cooked for >15 minutes at pressure cooker temps which is the equivalent of an autoclave.

 

@gfweb  I'd like some clarification on the highlighted points, please.  By "stay[ing] sealed" do you mean that the cooker isn't opened when cooking is done until such time as the mixture is transferred to storage containers? If left for several hours, such as overnight, wouldn't the sealed vent open naturally and break whatever seal the cooker might have?  How would that effect the concept of a sealed cooker?

 

Is the 15 minutes you mentioned additional time to reheat the contents after they have cooled down for several hours after cooking, essentially just reheating at pressure cooker temperatures?

 

 

[gfweb]

If you left it in the closed pot , even though vented, i dont see an overnight risk 

 

The 15 min at pressure referred to the original cook. And I'm sure it was longer. 

[haresfur]

6 hours ago, Shel_B said:

Thanks for linking the article.  Based on the article and my own experiences, I'll not be concerned about the safety of this batch of stock.

 

The article did mention flavor degradation as a possible side effect of leaving the stock/sauce/etc. out too long and then reheating.  A test of that idea may be worthwhile.

 

Be sure to let us know if you die

 

(I would risk it, too)

[pastameshugana]

Probably not the best reference point, but surely my grandmother isn't the only one who left soups on the stove (covered) over night if they weren't finished?

 

She would just re-boil them the next day before feeding us. Maybe my imagination, but it seems like it was always better the next day!

 

In fact, there is a pot of soup on MY stove right now from last night. Come lunch time, I'll get it up to a boil and enjoy away!

 

And the added benefit, if something does go wrong and I get a runny tummy, then I get a delicious lunch AND a free weight loss program... (mostly kidding)

[Shel_B]

 I'm not dead.  Made a chicken bog with the stock yesterday ... mmmm! 

No intestinal distress either. Thanks for your input, folks.

Edited September 22 by Shel_B
typo (log)

[Katie Meadow]

I find all this info to be a confusing mess of questionable science and luck. The idea of re-boiling stock the next morning after it sits on the stove and then cooling it down before refrigerating or freezing seems like an annoying waste of time, although it might be safer. In winter, if your kitchen is nice and cold at night I don't see a problem leaving the hot stock out at night if you can stand to deal with putting it away the next morning. But in warm weather I'ld rather not. My solution to this problem is to get the stock going early in the day and get the cooled stuff into containers in the fridge by dinner time. Maybe it's just me, but the last thing I want in the morning is the smell of chicken broth and the chore of dealing with it. If time is short, and you have an abundance of ice, sitting the pot in the sink to cool it down is effective. But again, extra work.

 

The idea of re-boiling an already made soup for fifteen minutes the next day seems particularly destructive to the poor soup.

[gfweb]

The science isnt questionable.

[weinoo]

I think in a restaurant setting, leaving stock out all night and then serving it to customers (no matter what you’ve done to it) might get you fired.

[gfweb]

15 hours ago, weinoo said:

I think in a restaurant setting, leaving stock out all night and then serving it to customers (no matter what you’ve done to it) might get you fired.

 To be sure.

 

But the regulations aren't always rational.  This stock was sterilized... literally.

 

I recall Ruhlman advocating leaving it out.... uncovered... on this very site.  That was a bad idea.

[OlyveOyl]

I was under the impression that once the pressure dropped (and you were able to open the lid) that the pot was no longer sterile. Once the pressure seal is broken by the drop, I can’t imagine that it would continue to be sterile.

[C. sapidus]

An autoclave is definitely capable of sterilizing chicken stock, as long as the proper time / temperature / pressure regimen is followed. A pressure cooker could certainly achieve the same end.

 

But once open to the atmosphere, there is the potential for the stock to be re-contaminated and, at the appropriate temperature range, for pathogens to grow.

 

Just to be a contrarian, I will point out that even an autoclave does not destroy prions (which, granted, are a special case).

[Bernie]

Aren't we getting a bit carried away here?

If indeed the pot was opened, then there is a small risk of contamination, but that depends a lot on the general environment.

If the stock was allowed to cool completely before it was opened, then even that risk is likely to be minimal. For meaningful contamination you need the bacteria/yeast/nasties and the right temperature range and sufficient time at the temperature for the bacteria to grow.

If the pressure was released but the pot still closed then it will still be sterile. (yes OK if you cooled it down below ambient and the vent allowed bi directional gas flow then you may introduce contamination from the air)

Another almost neglected criteria is the "surface tension" and the PH of the stock......real chemistry needed here..

 

By the way do prions actually multiply?

 

[gfweb]

@Bernie Good point, like viruses, prions require a living cell to multiply.