h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I used to know a bloke who would make a Bolognese sauce to last a week and leave it on the stove, reheating the whole thing every night. He is still alive as far as I'm aware.

That might be asking for it, but I've never really complied with the 'do not reheat more than once' rule either. Cook something properly, and you will kill all the bacteria regardless of how many times its been cooked before. The trouble comes when one crop of bacteria release all their nasties, then another, then another... so its more likely that your stew will just taste awful after a few reheats.

Cook your chicken properly at least once and it will kill the salmonella. It may pick up other things after time, but probably not salmonella unless you somehow manage to contaminate it from something else. Use your nose like cats do. If it smells fine, it probably is.

I always err on the side of caution with these things cos I don’t like being so Im probably not the best person to give advice. I’d throw away anything that was left out overnight just in case, but then I don’t like eating things that still have a day to go on the sell by date. I am always a bit nervous when it comes to freeze/reheating food and would love to see a guide on it? Had a look but didn’t see one on h2g2 but might just be searching the wrong bit?

>> I always thought things should be frozen immediately after cooking. <<

No, leaving things out won’t do you any harm. You should at least let them cool down a bit...overnight won't hurt.

>> just dont keep it in the freezer for long, a couple of weeks max? <<

Or 3 months, depending on your freezer. The time that food can be kept in a freezer is dependent on the freezer, not on how long the food was outside the freezer.

>> in most food safety courses they advise the 90min rule which is cooked, cooled and in fridge within 90mins. <<

The people who write these “courses” should be taken outside and shot. Really, it’s the only way to stop their pernicious nonsense being disseminated further.

This is why you read headlines about 30% of food being thrown away, which makes me really very angry. Health'n'safety fascism is ruining people's lives. You go ahead, Az. It won't kill you.

RF

"The people who write these “courses” should be taken outside and shot. Really, it’s the only way to stop their pernicious nonsense being disseminated further."

Yes, these "so-called experts" eh? Who needs science when you've got instinct.

Have you bothered looking into why people on courses are taught these things? The science behind it?

"This is why you read headlines about 30% of food being thrown away, which makes me really very angry. Health'n'safety fascism is ruining people's lives. You go ahead, Az. It won't kill you."

First, the reason so much food gets flung out is because it goes rotten. I live with someone who buys food all the time and leaves it to go off (some of it I manage to save and eat). There are a lot of people who buy, for example, lettuce and then a week or two later throw it out because it's gone brown.

"Heath'n'safety fascism" as you hyperbolically call it is based around responsibility. If you leave food overnight you'll *probably* be okay but there's a reasonable chance it'll give you a dose of the runs. Governments, supermarkets etc have to work on that assumption. Imagine someone buys some food, sticks to the date on the packaging then falls ill with food poisoning. Then they contact the manufacturer only to be told "well, there was a 25% chance of pathogens breeding to the level needed to make you ill but we thought what the hell, odds are in our favour!" The reason "use by" dates are used is nothing to do with some sort of strident mania, it's simply the reasonable expectation of the consumer to know that if he/she eats the food in alloted time they won't become ill.

Oh, bollocks, Zagreb. the 30% isn't folk chucking stuff away, it's supermarkets with food past its sell-by date. All they're worried about is being sued.

Yes. I do disagree with the "experts". "Experts" are frequently wrong, but they have a herd instinct.

I regularly eat food that's been left out. I reheat it, time and again. I ain't dead.

RF

"Yes. I do disagree with the "experts". "Experts" are frequently wrong, but they have a herd instinct."

So in spite of knowing nothing on the subject you feel you're in a position to challenge people who are experts on the same subject.

I come across these people time and time again. They're called cranks.

I have a degree in biochemistry & genetics.

If you want to call me a crank.

RF

""Experts" are frequently wrong, but they have a herd instinct."

No they don't, science is nothing to do with running with a herd as people have had to point out time and time again regarding the recent crankery over Global Warming and 9/11; running with a herd is more associated with "gut feeling" and "common knowledge" which, incidentally, seems to be the basis of your own conclusions.

Hmm. So how many people actually die of reheated stew then?

RF

"I have a degree in biochemistry & genetics.

If you want to call me a crank."

Neither of which have anything to do with food safety, unfortunately. And holding scientific qualifications does not immunise one against crankery; look into the backgrounds of a lot of GW deniers and one finds plenty of people with letters after their names (none of them experts in climatology, of course).

Oh stop being an arse. My point being, I know what scientific method is. I also know that a large amount of what is propagated as "science", isn't. Food safety is one of the areas where I have a large amount of scepticism.

RF

"Hmm. So how many people actually die of reheated stew then?"

I didn't say people "died" of "reheated stew", I said (and say again): You claimed that food left out is perfectly safe and offered nothing scientific to back that up. Other people quoted people who have taken qualifications and whose background is more scientific believe there is a risk. You dismissed this with some hyperbolic nonsense and the crankish claim that experts in a field can't be trusted but that you can.

"Oh stop being an arse. My point being, I know what scientific method is. I also know that a large amount of what is propagated as "science", isn't. Food safety is one of the areas where I have a large amount of scepticism."

If people doing food safety courses are being taught a lot of twaddle then you need something solid to back that up. Scepticism should be based on something more than "I've done this and this happened therefore it's rubbish". I also get annoyed at rubbish being passed-off as scientific fact but a lot of the recent reading I've done into it is about expert opinion being ignored in favour of twaddle: GW and the MMR scandal being two prime examples.

If you're simply being sceptical generally then fine, but my heckles are got-up by anyone pulling the "so-called experts" line.

I'm going to use what I learned in food safety class when I was going to be a waitress (and I'm thankful I got a better job before than remembering some of the pics).

Typically, if refrigerated food has been left out all night in warm tempreatures, it's best to toss it. More than likely you'll end up with food poisoning (this has happened to me when I ate something the next day by mistake). Doesn't mean you will, but the odds are not in yoru favor.

Now defrosted meat, if cooked and refrigerated, lasts a while and could be used in soup. If you put it back in raw, I'd suggest if you remove it from the 'fridge again that you cook all of it. Constantly defrosting and refrigerating meat can cause you problems, especially if ground meat.

In restaurants, you cannot reheat meat, only vegetables unless I'm mistaken, and even with the veggies, it's only one time. You must discard the vegetables after they're defrosted again.

It sort of goes to cooking meat as well. In restaurants, it's possible to have your steak rare because as long as it's a solid slab of meat, you can just cook it until it's browned on the outside. Inside, the meat is sterile unless the cow was infected before it became dinner. Ground beef - at least in the United States - they either won't do it period or make it clear that by ordering it you know that you're putting your health at risk eating the food that way (same with oysters and shellfish).

This is probably too much information, but hope it helps out some. Personally, I have a cast iron stomach for the most part and most foods won't bother me.

Experience of food safety classes may not be so applicable to everyday life - a restaurant has to be much more cautious than an individual to protect their reputation and business, but also because they produce much, much more food than an individual does, so the accumulated risks are higher for a restaurant than an individual. Similarly, government food safety guidelines have to be more stringent than they need to be because of CYA.

I don't worry about it much myself, but here's what Harold McGee in "Food & Cooking: An Encyclopaedia of Kitchen Science, History and Culture" has to say.

As far as meat is concerned, the two most dangerous bacteria are E. coli and salmonella. E. coli is killed at 68 degrees C (155 F). He doesn't say what temperature you have to get it to to kill salmonella, but a quick google suggests that 75 C should do it. Salmonella and other bacteria multiply at significant rates between 5-60C and so shouldn't be left in this range for more than two hours (oops az! ). Leftovers should be promptly refrigerated and reheated at least to 70C.

It seems then that as long as the food is heated to 75 C there's no problem. The bacteria that would have been growing might have caused some nasty chemical changes which would make it taste bad, but they'll all be dead if you've heated it to that temperature. But make sure you really have heated it to that temperature all the way through. I actually have a catering style probe that you can jab in to food to see what the temperature is internally. (I use it because I prefer my meat rare but not raw, not because I'm worried about food safety.)

But bear in mind that you get what you pay for and this advice came free...

if you re heat it to the point of boiling and keep it at boiling for a sufficient length of time, the science is that you will kill pretty much all the bacteria in the food. some moulds and fungi however produce toxins, so the issue of killing is irrelevant, and the food might still be harmful.

on a probability basis, it you recook the stew to boiling temperature, covered, for 10 minutes or more, the likelihood of you becoming ill is quite small.

the question is why you would bother. a chicken stew can be made for less than 5 dollars.

as an aside, the recommended temperature for many cold foods, including milk, is 4 degrees C or less. if you intend keeping milk (for the maxiumum best-by period) in the usual door space, you will need the thermostat set lower than this.

"Experience of food safety classes may not be so applicable to everyday life - a restaurant has to be much more cautious than an individual to protect their reputation and business, but also because they produce much, much more food than an individual does, so the accumulated risks are higher for a restaurant than an individual. Similarly, government food safety guidelines have to be more stringent than they need to be because of CYA."

True, but some of those are also good for home cooking, such as ground beef and all. The crossover ones from restaurant to home though are really good to learn though - such as the keep hot foods hot, etc., and the don't defrost stuff on the counter. Some don't listen to them, and in one case, I paid the price. That was a Christmas I don't think any in the family will forget. Didn't end up in the hospital, but I hated pretty much sleeping through most of the day away and only being able to stomach Sprite.

Home is different for me as well. Veggies and such, I'll reheat them again and again, and will keep spaghetti with mushrooms and RoTel tomatoes for about a week before I dump it out, if shrimp or tuna added, within 5. On meat, admittedly, most of the time I'm a pescarian, and make sure the fish is cooked to where it flakes. I don't like salmon or fish based sushi, and instead eat crab - which most places here use imitation, or a veggie roll. If I'm not that at the moment, I eat eggs instead - those I usually scramble until not runny.

If I eat red meat at a restaurant - if it's a steak it's medium well (just a bit pink, but cooked through) or hamburger steak - well done, no exceptions. That pic I saw in the video during the safety class was enough to make me tell waiters to return hamburger steak if it's the least bit pink.

for a serious gastro upset it is best to fast until it passes, which is seldom longer than 24 hours. the old 'cure' of flat lemonade or cola is an old wives' tale. for mild cases that don't involve vomiting or excessive runs, small amounts of soft drink, or better still, soda water, will suffice.

if you are so sick you risk dehydration, get yourself to a doctor or a hospital. a child with vomiting or the runs should always be seen by a doctor.

as for the food: if in doubt, throw it out.

RF, if you want to leave a pot of chicken stew out overnight then that is up to you, however someone who leaves a pot of chicken stew out overnight in summer when it can still be 70f some nights is asking for trouble in my opinion.
You may rubbish food safely courses RF but a lot of it is just common sense things they cover that many don't think about, like not putting raw meat above cooked foods in a fridge as the blood can drip onto cooked food which might not be noticed. One of the causes of a lot of food poisoning is reheating take aways and it often isn't the meat but the rice which everyone things is safe but isn't as a great breeding ground, food safety courses cover things like that too.
Sure food poisoning in healthy adults might be just vomiting and the runs, although surely people would want to avoid that, but in the very young or older person the effects can be much worse.

<> (me, about ten minutes ago)

Now *those* are words you don't hear very often.

<>

Not at 'casa az', antigravitas. I buy free range chicken (just breasts and thighs) for the stew. Then add about a kilo of potatoes, half a kilo of carrots, couple of big onions, two heads of garlic and some whole black peppercorns. Like I said, it usually lasts all week.

But this week we're trying to use it up more quickly so yesterday we had stew for both lunch and dinner.

az