stock

[glennbech]

I had to reduce my beef stock by half, in a hurry this morning, and left a boiling hot reduced stock to cool in my saute-pan uncovered. I'll be back from work in 8 hours. Can anyone tell me how easily a stock gets spoiled? Does the same rule apply for chicken, duck and other stocks?

[paul o' vendange]

Sorry, but past 4 hours, you're inviting unacceptably high-levels of contamination. This applies to everything. Additionally, it isn't as if 4 hours is a magic benchmark - any time you leave food out within the temparature range of microbial contaminants, with adequate nutrition (your food), and environmental factors (i.e., air, and not properly canned anaerobic environment), you will be getting contamination. 4 hours is a threshold estimate, but no time left out is good.

[tim]

Glen,

Bring that stock to a boil for ten minutes and you will destroy all of the bacteria.

Tim

[Fat Guy]

Just to be clear, there's a difference between spoilage and contamination. In most introductions to food safety, you're taught that food can look, smell and taste fresh and delicious, but still be contaminated and therefore a vehicle for food poisoning. For its part, spoilage is basically what happens when something gets old. Refrigeration generally retards spoilage, as do various other technologies. But most fresh foods -- maybe not raw, dead shellfish, but most foods -- can be left out for a day or more (often much more, as in the case of an apple or a grapefruit) without spoiling. It's possible for food that's quite fresh, however, to become contaminated by bacteria. So, your stock is just not likely to spoil in eight hours. It may, however, grow harmful bacteria, which may be odorless, colorless and flavorless. Beef stock is, indeed, used in labs as a medium for growing bacteria, because it provides such favorable conditions. It's true that boiling will kill bacteria, so if you're only serving the stock to yourself and you're comfortable with the risk then sure, boiling is an option. I wouldn't suggest serving it to a restaurant full of people, though -- you never know if every bit of what you're dealing with has reached the right temperature. Cross-contamination is also a fear. That being said, I've left stock out that long and used it -- I can't recommend it, but I've done it.

[glennbech]

Thanks for the answers; I'll probably take my chances with it. I'll report in the thread if I get sick :-)

[stephle]

I'd agree with FatGuy on this -- I've also done it (done worse, left it out overnight unrefrigerated) and lived to tell the tale. Granted, it was cool in my kitchen and I did as was suggested above and brought it up to a boil for many many minutes before using it.

My only caution which I'm sure you've already considered is to make sure you're not going to use this in anything that might go to children, the elderly or anyone with a compromised immune system. They might not be able to fight off something as easily as those of us with constitutions like a horse might be able to

[amccomb]

Glen,

Bring that stock to a boil for ten minutes and you will destroy all of the bacteria.

Tim

←

That may kill the bacteria, but it won't kill the toxins the bacteria produce as waste, which is many times more dangerous than the bacteria themselves.

[andrewB]

Glen,

Bring that stock to a boil for ten minutes and you will destroy all of the bacteria.

Tim

←

That may kill the bacteria, but it won't kill the toxins the bacteria produce as waste, which is many times more dangerous than the bacteria themselves.

←

so here's a question on the opposite end of the spectrum: why is it that when a hot pot of stock is placed directly into the fridge, it turns sour?

reason i asked is because of an age old 'catch-22.' if you leave it out, it will harbor bacteria. if you put it in, it will sour...

[Fat Guy]

I'm not sure either one of those statements is entirely correct.

It is worth noting that there are types of food poisoning that can survive heat. However, I would not go so far as to say that toxins are the big concern in the world of foodborne illness.

There may be types of food poisoning from toxins of which I'm not aware, but my understanding is that the big one is staphylococcal food poisoning. It is indeed caused by toxins produced by the staph. And it's quite common. However, it tends not to be serious. According to the National Restaurant Association:

Staphylococcal food poisoning is one of the most commonly reported illnesses in the United States. Staphylococcal poisoning is an intoxication; it is caused by toxins that are produced by the staph. bacteria. When a person consumes food that is contaminated with staph. toxins, that person becomes ill from the toxin, not the bacteria. Deaths are rare and the duration of the illness usually lasts only one or two days. However, sometimes the intensity and severity of the symptoms require hospitalization.

There are also a couple of other types of food poisoning in which toxins are implicated, like Clostridium perfringens and Clostridium botulinum. But the big categories of dangerous foodborne illness, like E. coli, salmonella, listeriosis, hepatitis A and Norwalk virus are not toxin-related.

In terms of refrigeration souring the stock, I've never heard of that and have never experienced it.

[Live It Up]

so here's a question on the opposite end of the spectrum: why is it that when a hot pot of stock is placed directly into the fridge, it turns sour?

reason i asked is because of an age old 'catch-22.' if you leave it out, it will harbor bacteria. if you put it in, it will sour...

←

The reason stock spoils if you put it directly into the fridge is that the heat from the stock raises the temperature in the fridge, causing it to cool too slowly and spoil. The best thing to do is to divide the stock into smaller containers and cool those to room temperature before refrigerating. This isn't a problem with smaller amounts. Alton Brown also had a pretty ingenious solution which is to freeze some bottles of water and float those in your stock to cool it.

[andrewB]

so here's a question on the opposite end of the spectrum: why is it that when a hot pot of stock is placed directly into the fridge, it turns sour?

reason i asked is because of an age old 'catch-22.' if you leave it out, it will harbor bacteria. if you put it in, it will sour...

←

The reason stock spoils if you put it directly into the fridge is that the heat from the stock raises the temperature in the fridge, causing it to cool too slowly and spoil. The best thing to do is to divide the stock into smaller containers and cool those to room temperature before refrigerating. This isn't a problem with smaller amounts. Alton Brown also had a pretty ingenious solution which is to freeze some bottles of water and float those in your stock to cool it.

←

but then if the stock sours because it cools too slowly, why would it also not sour being left out(which it doesn't)? this only happens with chicken stocks for me and i have never had an answer for it...

[paulraphael]

I use a set of stainless mixing bowls. I divide the hot stock among them and float them in a sink full of cold water. I shuffle the bowls around and stir the stock within them every few minutes ... when the water in the sink gets warm, I replace it with new cold water. Usually about three changes of water is enough to get the stock to room temperature. From simmering to fridge is about 45 minutes.

The stainless bowls have plastic covers, so I just cover them and set them in the fridge. when they cool i skim the fat and put it into the final containers.

[paul o' vendange]

This is an interesting discussion; there is something I would also like to clarify. I think everything has to do with thresholds - sensory thresholds ("yuck - spoiled!"), and thresholds past which the body will feel the ill-effects of contaminants, or enough contaminants will enter the body to replicate before the body can fight off the infection, hence, sickness.

There is little "absolute" in cooking, in terms of contamination, absent sterilization - the absolute killing off of all microbes and their spores, and maintenance of this environment through aseptic practice (such as canning). I think what we do is better named sanitization- we reduce microbial loads to allowable limits, and make it difficult for these beasties to grow past allowable limits by heat, then cold. Foodborne, even airborne contaminants exist everywhere - we are eating contaminated food everyday, with every bite, or nearly so.

When I posted "I wouldn't use it," what I should have said is "I wouldn't use it for service, or more than that day, or next." In other words, the scenario I envisioned was leaving the stock out, then putting it away. The population density of contaminant microorganisms may or not be large enough to surpass threshold levels by the end of the first day, but even in the refrigerator, absent a lengthy enough boil to kill off the bacteria and spores that result from the period sitting out, it will only retard what will be an inevitable process. A few days later at best, I would bet, and the stock is spoiled. Beyond this, even if the microbial load was itself low, I would wonder about their by-products, producing off-effects. Not worried about toxins, so much, in an aerobic environment, as much as nasty by-products of respiration and replication.

Re: hot stock in a fridge. I think two problems are at hand: the hot stock may indeed heat up the fridge, as posted above, such that the cooling period is unduly long (large vessel/small fridge area). Or, the ability of the fridge to cool the liquid inside the stock vessel by external, ambient temp is really inefficient; either way, the length of time inside the microbial growth zone is long. The immersion stick method provides direct heat transfer, and is more efficient (rate of heat transfer is higher) in cooling the liquid to reasonable ranges.

Just to be clear, there's a difference between spoilage and contamination. In most introductions to food safety, you're taught that food can look, smell and taste fresh and delicious, but still be contaminated and therefore a vehicle for food poisoning. For its part, spoilage is basically what happens when something gets old. Refrigeration generally retards spoilage, as do various other technologies. But most fresh foods -- maybe not raw, dead shellfish, but most foods -- can be left out for a day or more (often much more, as in the case of an apple or a grapefruit) without spoiling. It's possible for food that's quite fresh, however, to become contaminated by bacteria. So, your stock is just not likely to spoil in eight hours. It may, however, grow harmful bacteria, which may be odorless, colorless and flavorless. Beef stock is, indeed, used in labs as a medium for growing bacteria, because it provides such favorable conditions. It's true that boiling will kill bacteria, so if you're only serving the stock to yourself and you're comfortable with the risk then sure, boiling is an option. I wouldn't suggest serving it to a restaurant full of people, though -- you never know if every bit of what you're dealing with has reached the right temperature. Cross-contamination is also a fear. That being said, I've left stock out that long and used it -- I can't recommend it, but I've done it.

←

Edited April 16, 2007 by paul o' vendange (log)

[chappie]

I routinely throw chicken carcasses (usually from rotisserie birds) plus any veggies I have on hand, garlic, herbs, peppercorns, fish sauce, etc. into a big pot and simmer well into the night, then turn off and let cool till morning. Last night I turned the heat off at 2 a.m., then strained it out at 8 a.m.

I have done this for years, but then again I also reboil the stock when I'm making soup. I have never gotten ill from my own chicken juice.

Then again, I grew up with a father who keeps things in his fridge for decades, so I probably have a veteran gut.

[SeaGal]

I cool my stock fairly quickly by filling the sink with water and ice and then putting frozen blue ice packs in it (I always keep several of them frozen in my freezer). Then, I place the stock pot (unless I'm using my monster stock pot in which case I'll tranfer it to 2 smaller containers) right into the sink and rotate either the pot or the ice packs surrounding it from time to time. It usually cools to room temperature in about 1/2 hour or so and then I put it into smaller containers and refrigerate it. After it's completely cooled, I then freeze whatever stock I won't be using up within a couple of days.

[Qwerty]

Here's my $.02.

I would throw it out. I never take a chance when it comes to food safety. If there is ever a question it is better to be safe than sorry.

I've had serious food poisening a couple of times in my life. I'm talking sitting-on-a-toilet-holding-a-trash-bucket kind of sick. I would have gladly traded any of those meals that made me sick for my health. Those were BAD, BAD 12-24 hour days.

Remember, too, that most of these toxins and bacteria take about a day to manifest themselves. So you can feel fine for about 24 hours (give or take a few), and then BAM, you're down and out.

Like I said, I can almost guarantee that'd you'd trade whatever you ate with that stock for not being sick like that.

Am I saying that you will get sick if you use it? No, not at all. In fact, odds are that you will be OK. But again, I wouldn't take that chance.

Good luck

[glennbech]

Here's my $.02.

I would throw it out. I never take a chance when it comes to food safety. If there is ever a question it is better to be safe than sorry.

I've had serious food poisening a couple of times in my life. I'm talking sitting-on-a-toilet-holding-a-trash-bucket kind of sick. I would have gladly traded any of those meals that made me sick for my health. Those were BAD, BAD 12-24 hour days.

Remember, too, that most of these toxins and bacteria take about a day to manifest themselves. So you can feel fine for about 24 hours (give or take a few), and then BAM, you're down and out.

Like I said, I can almost guarantee that'd you'd trade whatever you ate with that stock for not being sick like that.

Am I saying that you will get sick if you use it? No, not at all. In fact, odds are that you will be OK. But again, I wouldn't take that chance.

Good luck

←

I've been that sick from eating cheese pancakes at a dirty truck stop in the middle of nowhere in Turkey, South of Istanbul in the middle of the night. They had probably been lying around for ages, but was quite tasty. The effect came in about 20 -30 minutes, and was "acute" .)

I was also seriously sick from eating some kind of milk porridge at a local flea market in Bogota, Columbia... Not to mention some strange Thai Insect with a juicy inside I consumed while beeing slightly intoxicated by another toxin

I don't think I'll die from my stock, it, and if there is just a *slight* chance that i *Might* get sick, and that's the worst it can get, I think I'll take my chances with it .-)

Thanks for all the responses

[aschbren]

Once you get a wort chiller, you'll never want to go back.

http://www.northernbrewer.com/wort-chillers.html

Just run cold water through it and you get storeable temperatures much, much faster than any other technique I've ever seen. I'm surprised they're as rare as they are in kitchens.

[glennbech]

Once you get a wort chiller, you'll never want to go back 

Maybe if I made 10-15 liters each time

Edited April 17, 2007 by glennbech (log)

[DCP]

Once you get a wort chiller, you'll never want to go back.

http://www.northernbrewer.com/wort-chillers.html

Just run cold water through it and you get storeable temperatures much, much faster than any other technique I've ever seen.  I'm surprised they're as rare as they are in kitchens.

←

*Sigh*. Another kitchen gadget to buy. There's only so much room in my cupboards!

[project]

Timely thread!

<br><br>

As I type this, I've just finished making 11 1/2 quarts of

chicken soup made with four whole chickens, total weight as

purchased 21 pounds. Right, it's <i>meaty</i> soup!

<br><br>

I have the soup in a 12 quart, stainless steel, Vollrath stock

pot. It's a heavy thing, with a thick aluminum plate on the

outside of the bottom, and handles heavy enough to tow a car!

<br><br>

The soup temperature is now at 160 F, and I will warm it a

little more to be sure of sterilization.

<br><br>

Then I will have to face the problem of this thread -- how to

cool the pot!

<br><br>

I have two techniques:

<blockquote>

<LI>

First, do not cover the pot, at least not until it is fully

chilled in the refrigerator. The reason is, before the

contents are fully chilled, there will be condensation on the

underside of a cover, and that condensation will drip into the

pot contents and maybe start bacteria growth.

<LI>

Second, do include some fat in the contents so that get a

layer of fat above the water-based contents. Due to the

heating, this layer of fat will have sterile contents under

it, and the fat, I hope, will help protect the water-based

contents from bacteria from the air. </blockquote>

Once the pot is fully chilled, then I will lift off the fat

layer and put a lid on the pot.

<br><br>

I don't have a microbiology lab to check if these techniques

are working to keep down bacteria growth, but so far my own

soups and stocks haven't made me sick!

<br><br>

When I made the soup, I started with

<blockquote>

<LI>

2 pounds of coarsely sliced, large, yellow globe onions

(weighed just before adding to pot, that is, AFTER peeling and

slicing)

<LI>

1 pound of sliced carrots

<LI>

1 pound of sliced celery

<LI>

1/3 C minced, fresh, peeled garlic

<LI>

6 dry bay leaves

<LI>

1/4 C home grown Rosemary leaves

</blockquote>

Added water to cover and simmered to soften (and, thus, make

room enough in the pot for two chickens).

<br><br>

Added first two chickens and water to cover. The 12 quart pot

was nearly full.

<br><br>

Simmered the first two chickens until they were cooked then

removed them and let them drain and cool.

<br><br>

Meanwhile, added the second two chickens to the pot, simmered

them, removed them, let them drain and cool.

<br><br>

So, right, got a 'double' stock, and, yes, it will gel at room

temperature.

<br><br>

Took the chickens apart and put the meat in bowls and put the

scraps back into the stock pot.

<br><br>

Chilled the meat (in bowls, uncovered) and let the pot simmer

overnight.

<br><br>

Strained the stock and discarded the solids.

<br><br>

Cleaned the stock pot and added

<blockquote>

<LI>

3 pounds of finely diced, large, yellow globe onions

<LI>

1 1/2 pounds of sliced carrots

<LI>

1 1/2 pounds of sliced celery

<LI>

the meat from the two chickens, diced

<LI>

stock to cover

</blockquote>

Brought to simmer.

<br><br>

Have about 1 1/2 quarts of stock, dark color, that will gel at

room temperature, left over and can use for another purpose,

e.g., doing something with chickens other than making soup!

<br><br>

My first candidate idea:

<blockquote>

Get two more chickens. Take apart. Use the scraps for a

Chinese-style light chicken stock. Use the thigh and

drumstick meat for a Chinese-style stir fry, using some of the

Chinese style stock.

<br><br>

For the breast meat, flour it, brown it in chicken fat, place

in a baking dish, add a sauce made with a white roux and some

of the chicken stock, and bake uncovered until done.

</blockquote>

Now, when I take the chicken fat off the chilled chicken soup,

I'm supposed to use the fat to make dumplings, right?

<br><br>

Suggestions for how to do that?

<br><br>

I did try one technique: Combine egg whites, milk, and

chicken fat, mix, and warm, add flour, mix, and warm until

thick, add egg yolks and mix, and drop by spoonfuls into

boiling stock.

<br><br>

Mostly it didn't work: The dough, batter, or whatever it was,

just came totally apart in the stock. Bummer.

<br><br>

So, I heated the remaining batter until it was really a paste,

let it cool to a thicker paste, formed balls, and simmered

those. It gave some crude dumplings and a thick layer of

stuck batter on the bottom of the pot. Not good.

<br><br>

The dumplings didn't taste very good. Actually the recipe

suggested adding chives to the batter and I should have since

so far the only vegetables ready to eat in my back porch herb

garden are the chives!