Dangerous advice?

[Kurrawong_Kid]

In a recent issue of YM there was a photo of a couple loading hot food into a Thermos before setting off on a passage. This seemed a good idea to me. I mentioned this to SWMBO, who is a bit of a scientist, and she was mightily unimpressed!!

According to her, this is highly dangerous, because any bacteria not killed in the initial cooking have ample opportunity to proliferate with gastric consequences.
She states she will only reheat (and then only once) food if it is sharply cooled after the initial cooking and then refrigerated before reheating.

Is she correct?

 

[fireball]

Probably technically correct ...

But how many dinners have sat plated up ready to eat when the OH gets home ... or is interupted because the phone rings or someone at the door ...

Dishclothes and teatowels are reported as carrying the most germs/bacteria in the kitchen ... so anything you eat with or from is likely to contain something 'bad' for you ...

Your stomach already has bacteria in it ... and can deal with a heck of a lot more ... not that that is any reason to inflict more on yourself ... but the risk must be pretty low ... otherwise we'd all be off work sick the whole time ...

 

[photodog]

So, we shouldnt eat hot food from a thermos flask anymore.


ITS HEALTH AND SAFETY GONE MAD!!!

 

[Slow_boat]

Technicaly she is probably right but in the real world I've been eating hot food from a thermos for years with no ill effects. I like steak tartare, too. I also use water from the tank for hot drinks and washing up, providing it doesn't smell. If it does, I draw it through till it doesn't!

Not died of bird flu yet, either.

BTW, when I have leftovers at home I leave them on the side to cool before putting them in the fridge or freezer. Is that the 'wrong' way round?

 

[capt_courageous]

Hi
' I mentioned this to SWMBO, who is a bit of a scientist. ' Which bit ?

 

[emsworthy]

I also use water from the tank for hot drinks and washing up,

What d'ya mean? I use water from the tank to make cold drinks too! I haven't died yet either.

When camping as kids we would drink water from practically anywhere that wasn't brown or smelly. I'd like to think the tank on my boat is a damned sight better than that!

 

[duncan]

the idea of keeping food (or beverages) hot (enough) over a period is completely different from the process of storing pre cooked meals for subsequent reheating.

cook/chill is certainly the accepted process for the latter nowadays whilst the former has product based time limits as well as environmental rules etc

however you also need to see the bigger picture with such things and the delivery of hot(warm!) food safely to someone on watch may positively impact the safety of the craft and occupants, whist the avoidance of need to use a stove in a seaway, then plate and transport to cockpit is clearly a potentially hazadous process best avoided!

give me the thermos every time

 

[xxyyzz]

At what point does a "hot drink" become "food" though?

No-one would think twice about keeping tea in a thermos.

So, hot chocolate?

Soup?

Stew?

Curry?

Steak and chips?

 

[whipper_snapper]

According to her, this is highly dangerous, because any bacteria not killed in the initial cooking have ample opportunity to proliferate with gastric consequences.
......
Is she correct?

Sort of. Partly cooked food with a thriving bacterial population will obviously become very nasty if allowed to hover around 'warm' as they cool in the flask.

But that is true of all cooking and storage. The solution is to kill all the bacteria in the initial cooking! That is not hard. To further improve it, scald the flask with boiling water before you add the very hot food. Close the lid and you have a damn near sterile storage system no matter how many times it has been heated and cooled. Bacteria will not thrive as the contents cool - because you killed them.

She states she will only reheat (and then only once) food if it is sharply cooled after the initial cooking and then refrigerated before reheating.

Is she correct?

No. This is an oft repeated mantra with little logic. It can be perfectly safe to heat, cool, reheat, freeze, thaw, repeatedly. On the other hand it can kill you if done stupidly. Just apply common sense and don't allow food, especially inadequately cooked food, to hang around, especially with bits of it (eg the middle of a big lump) at 'warm' temperatures. Beyond common sense and the simple knowledge that bacteria are easy to kill with heat, you just need to remember that some lethal bacterial toxins are not destroyed by cooking. So don't provide circumstances where they can accumulate.

 

[Jinks]

I was always told never to put hot food in the fridge. Don't know why and don't know if it's correct advice but as a result I never do. Cover it until cool and then put it in. No harm has befallen me yet.

As an aside, I was also told that food poisoning following an Indian or Chinese meal is almost always caused by the rice - a real breeding ground for bacteria apparently - and if you're going to reheat a takeaway make sure the rice is heated thoroughly. Don't know if that's true either.

 

[bedouin]

Seems a little misguided to me.

As with reheating any pre-cooked food it would be important to make sure that the food is heated through before putting it in the flask.

While I am sure her advice is technically correct, I am sure most of us have let leftovers cool naturally and then reheated them the following day without dying.

 

[lw395]

It's probably something to be aware of.
I think you will be OK if the food is piping hot when it goes into the thermos.
Most 'boat food' is prepared from fairly sterile ingredients, but I would make sure that any fresh stuff is properly cooked through.
Even a mild stomach upset can be very unpleasant on a boat, so best not to take chances.

 

[photodog]

I am sure most of us have let leftovers cool naturally and then reheated them the following day without dying.

ooh... dont know about that... only just last week I reheated some Windsor Brown and then died shortly afterwards.

Could it have been the soup?

 

[greenalien]

I was also told that food poisoning following an Indian or Chinese meal is almost always caused by the rice

Yes, that's true. One of the worst cases of food poisoning I've ever seen was from a vegetarian rice dish eaten at a beautiful shoreside taverna in Levkas - made my 2 crew violently sick (at both ends, as it were...) for 2 days - luckily, I ate something else!

 

[johnalison]

I don't share whipper snapper's confidence that cooking can be relied upon to kill all bacteria, let alone their spores. However, I wouldn't have thought that the risk from piping hot food kept in a thermos flask was enough to worry about if the time is kept to just a couple of hours.

It used to be said that you should never cook food more than twice, when they really meant you shouldn't cool food more than once. Putting hot food in a fridge will raise the temperature in the fridge and may cause other items to spoil.

 

[SailBobSquarePants]

I was always told never to put hot food in the fridge. Don't know why and don't know if it's correct advice but as a result I never do. Cover it until cool and then put it in. No harm has befallen me yet.

The rationale for this is that putting hot food in the fridge will take an awful lot of power or ice to chill it to storage temperature, whereas leaving it to chill to room temp gets it halfway there at no cost to the fridge or it's other contents.

So...YES it's not a bad idea, but you should NOT allow it to sit at room temperature for any length of time, because that is when the bacteria can multiply.

I would suggest that you content yourself with leaving it stand for 10-15 minutes to reach near room temp, and then put it straight in the fridge. Overnight is certainly too long, but you could probably get away with half an hour or even more...too many variables to know what is the max for each dish. Say 10-15 if using an electric fridge, maybe 20-30 if using ice on board, and you are safe...

 

[Danny Jo]

In a recent issue of YM there was a photo of a couple loading hot food into a Thermos before setting off on a passage. This seemed a good idea to me. I mentioned this to SWMBO, who is a bit of a scientist, and she was mightily unimpressed!!

According to her, this is highly dangerous, because any bacteria not killed in the initial cooking have ample opportunity to proliferate with gastric consequences.
She states she will only reheat (and then only once) food if it is sharply cooled after the initial cooking and then refrigerated before reheating.

Is she correct?

Perhaps, although I think it's stretching the point to describe the practice as highly dangerous.

Most food poisoning germs are killed at the pasteurizing temperature of 71 degrees Celsius. And most food poisoning germs multiply best at temperatures in the range 10 - 40 degrees Celsius. Keeping food at a temperature of below 4 degrees or above 63 degrees more or less guarantees that food poisoning organisms cannot thrive.

But bacteria can survive at low temperatures, and one or two types survive pasteurization as relatively heat-resistant spores. Food that was relatively safe (i.e. low levels of bacterial contamination) when put into the fridge can become dangerous if left standing around at ambient temperatures for some hours. And food contaminated with the spores of Bacillus cereus (commonly found in dried products like rice) or Clostridium perfringens (commonly found in raw meat) that has not been cooked at a high enough temperature or long enough to kill the spores, and allowed to cool, can become dangerous if subsequently kept at ambient temperatures for some hours. This is why the conventional food safety advice to caterers and householders is "Keep hot food hot and cold food cold".

So putting hot food in a thermos is OK if it is almost boiling when it goes in and still piping hot when you consume it. The other trick used by sailors is to pressure cook a stew and leave it in the pressure cooker. Pressure cooking for 10 minutes (not including the time required to heat the food through) at maximum pressure (about 34psi) kills all food poisoning bacteria including the spores of Bacillus and Clostridium. Here the only danger comes from recontaminating the food after it has cooled. The chance of a food poisoning bacterium being drawn in with the air as the pressure cooker cools is too small to worry about in my view. That just leaves the germs carried in by kitchen utensils, so pressure cooked food is best left undisturbed until you are ready to eat it.

However if your hot food is not piping hot you should reheat it to be absolutely safe. Edit: I can see a flaw in this advice - what's piping hot? Er, too hot to swallow. Sheesh, it's impossible to be risk-free, innit?

 

[bendyone]

Are bacteria killed in a microwave?

 

[sarabande]

If you are referring to an empty microwave with just a few million superficial bacterial lurking, then I don't know, but it might give a few of them a headache.

If you mean the bacteria in food inside a microwave, then it needs to be heated above the critical temp, and ALL the food at that temp, not just the middle...

 

[sky7liner]

Dangerous practice?

I suspect that food scientists won't be satisfied until we're all forced to eat only pasteurised food. Don't ever take her round a French country market. When she sees the cheese counter she'll probably have apoplexy.