# "Ensure product is piping hot before eating" - Why? **URL:** \ **Category:** Factual Questions\ **Created:** [January 22, 2008, 9:49pm UTC](https://boards.straightdope.com/t/ensure-product-is-piping-hot-before-eating-why/434574 "2008-01-22T21:49:28Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [January 22, 2008, 9:49pm UTC](https://boards.straightdope.com/t/ensure-product-is-piping-hot-before-eating-why/434574/1 "2008-01-22T21:49:28Z")
The phrase “Ensure product is piping hot before eating” seems to pop up in the heating instructions of just about every convenience food, even things that you could happily eat cold, like baked beans or sausage rolls. Presumably most “cook chill” foods, like microwaveable curries, would also be perfectly safe to eat cold, and the heating is purely to make them more pleasant to eat. I wouldn’t be putting my health at risk by just warming it to tepid and tucking in, would I? So why this “ensure food is piping hot” spiel? Is it just to make sure we’re in the habit of heating all foods thoroughly so that we’re not caught out by things we actually do need to cook, or is there some other reason? ---
**Author:** ![Gfactor](https://avatars.discourse-cdn.com/v4/letter/g/9de053/32.png) [@Gfactor](https://boards.straightdope.com/u/Gfactor)\ **Post date:** [January 22, 2008, 9:52pm UTC](https://boards.straightdope.com/t/ensure-product-is-piping-hot-before-eating-why/434574/2 "2008-01-22T21:52:45Z")
I’ve got no idea why, but Sam over at the Food Standards Agency sure seems to love the phrase: [http://www.eatwell.gov.uk/asksam/keepingfoodsafe/asksamcooking/](http://www.eatwell.gov.uk/asksam/keepingfoodsafe/asksamcooking/) These people seem to agree: [http://www.nhsborders.org.uk/view\_item.aspx?item\_id=17052](http://www.nhsborders.org.uk/view_item.aspx?item_id=17052) ---
**Author:** ![Alive\_At\_Both\_Ends](https://avatars.discourse-cdn.com/v4/letter/a/73ab20/32.png) [@Alive\_At\_Both\_Ends](https://boards.straightdope.com/u/Alive_At_Both_Ends)\ **Post date:** [January 22, 2008, 9:59pm UTC](https://boards.straightdope.com/t/ensure-product-is-piping-hot-before-eating-why/434574/3 "2008-01-22T21:59:11Z")
Presumably it’s to ensure that any bacteria have been killed off before you eat the meal. Food poisoning is no fun. ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [January 22, 2008, 10:07pm UTC](https://boards.straightdope.com/t/ensure-product-is-piping-hot-before-eating-why/434574/4 "2008-01-22T22:07:56Z")
It’s not just in the UK. I’ve noticed in the last year or so in the US that more and more frozen foods include the actual degree of hotness (in Fahrenheit) that a food should be heated to. I assumed, but do not know, that food labeling laws were changed to require specificity for safety concerns. ---
**Author:** ![groman](https://avatars.discourse-cdn.com/v4/letter/g/73ab20/32.png) [@groman](https://boards.straightdope.com/u/groman)\ **Post date:** [January 22, 2008, 10:25pm UTC](https://boards.straightdope.com/t/ensure-product-is-piping-hot-before-eating-why/434574/5 "2008-01-22T22:25:49Z")
[QUOTE=WhyNot] It’s not just in the UK. I’ve noticed in the last year or so in the US that more and more frozen foods include the actual degree of hotness (in Fahrenheit) that a food should be heated to. I assumed, but do not know, that food labeling laws were changed to require specificity for safety concerns. [/QUOTE] However, I have never seen the phrase “Ensure product is piping hot before eating”, which sounds ludicrous to me. You can’t eat something that’s piping hot, or rather, _I_ can’t eat anything that’s piping hot. Most American product labels, instead, contain cautions about letting it cool down before eating and cooking thoroughly, sometimes specifying specific cooking temperatures. I don’t know if people cover their mouth with asbestos or what… ---
**Author:** ![Ferns](https://avatars.discourse-cdn.com/v4/letter/f/90ced4/32.png) [@Ferns](https://boards.straightdope.com/u/Ferns)\ **Post date:** [January 22, 2008, 10:26pm UTC](https://boards.straightdope.com/t/ensure-product-is-piping-hot-before-eating-why/434574/6 "2008-01-22T22:26:19Z")
[QUOTE=Colophon] The phrase “Ensure product is piping hot before eating” seems to pop up in the heating instructions [/QUOTE] I’ve heard the phrase, but have actually never seen that written on a package. What _is_ “piping” anyway? ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [January 22, 2008, 10:28pm UTC](https://boards.straightdope.com/t/ensure-product-is-piping-hot-before-eating-why/434574/7 "2008-01-22T22:28:07Z")
[QUOTE=Alive At Both Ends] Presumably it’s to ensure that any bacteria have been killed off before you eat the meal. Food poisoning is no fun. [/QUOTE] Yes but my point is that you see it on foods that you could eat cold with no problem at all, like tinned baked beans. The food is in a tin, it’s sterile, I could scoop it out and chow it down as is. So why do the instructions tell me that, if I heat it up, it has to be “piping hot”? Same with ready-to-eat sausage rolls and pies. And why “piping” hot anyway? Am I meant to be listening out for a Highland reel coming from the microwave? 😉 Edit: **Ferns** beat me to it. I assume that it originally came from “whistling”, like a kettle when it boils. Anyone? ---
**Author:** ![casdave](https://avatars.discourse-cdn.com/v4/letter/c/c6cbf5/32.png) [@casdave](https://boards.straightdope.com/u/casdave)\ **Post date:** [January 22, 2008, 10:30pm UTC](https://boards.straightdope.com/t/ensure-product-is-piping-hot-before-eating-why/434574/8 "2008-01-22T22:30:19Z")
The problem with cooking food and then allowing it to cool in the correct manner is that although it kills off the food poisoning bacteria that are in the normal (vegetative) state ie, the ones that are growing and multiplying, there are a small number of bacteria that have developed a defence mechanism. The are bacteria such as Bacillus Cereus and Clostridium Perfringens, to name the main ones, and what they do is to form a protective casing around their nucleus. This occurs when conditions are unfavourable, such as during cooking, but can also be due to high acidity or some others. Normal cooking temperature is not usually able to kill off those spores, which remain dormant until more favourable conditions arise. These can be killed by rather higher temperatures, but we will leave that for the moment. So, you cook your food, preferably above 75C although 70C will likely be ok, and chill it **rapidly** to below 4C. This means that the few remaining bacteria in the form of spores do not get much chance to regroup, its now too cool for them to multiply. You can eat this cold, within a certain period of time. Your next option is to heat it up, but if you only heat it up to , say, moderately warm such as maybe 30C-40C, those spores will have ideal conditions for multiplication, and this can be made very much worse by holding this food at such a temperature for a period of time such as on a hot trolley, or counter display. The manufacturers will usually state that you can only safely reheat food once, and by ‘piping hot’ they actually mean back up to cooking temperature 70C-75C. Rice is one notorious risk in this category of food, as it harbours Bacillus Cereus, and rice is often pre-prepared for later reheating in fast food places such as Chinese and Asian restaurants. Storage of pre-cooked foods must always be done at either hot temperatures, above 63C, or below 4C, and never anything in between. If you want to reheat the food, the advice is only do this once, and always to cooking temperatures 70C-75C and always all the way through - localised cooler areas may allow bugs to multiply. If you are already keeing cooked food at 4C and you reheat and consume absolutely immediately, like you might at home, then the spores will not have enough time to multiply to an infective level, however the food suppliers cannot know what you intend to do and so make the safest recommendation by assuming people will hold food for periods of time before consuming. ---
**Author:** ![Gfactor](https://avatars.discourse-cdn.com/v4/letter/g/9de053/32.png) [@Gfactor](https://boards.straightdope.com/u/Gfactor)\ **Post date:** [January 22, 2008, 10:33pm UTC](https://boards.straightdope.com/t/ensure-product-is-piping-hot-before-eating-why/434574/9 "2008-01-22T22:33:05Z")
[QUOTE=Colophon] And why “piping” hot anyway? Am I meant to be listening out for a Highland reel coming from the microwave? 😉 [/QUOTE] > [@](#): > > Meaning > > Very hot, usually referring to food. > > Origin > > In Scotland, ceremonial dishes of food are often brought to the table to the accompaniment of bagpipes, i.e. they are ‘piped in’. This could easily be imagined to be the origin of ‘piping hot’. It isn’t though. The derivation of this little phrase is the sizzling, whistling sound made by steam escaping from very hot food, which is similar to the sound of high-pitched musical pipes. > > An early citation of the phrase is given in Philemon Holland’s translation of Pliny’s Historie of the world, 1601: > > ``` > "Beanes... fried all whole as they be, and so cast piping hot into sharp vineger." > > ``` [http://www.phrases.org.uk/meanings/283850.html](http://www.phrases.org.uk/meanings/283850.html) > [@](#): > > The sense of piping that’s relevant here is the one for making a musical sound, as by playing the pipes. The idea is that a dish that’s piping hot is one so hot it makes a sizzling or hissing noise, perhaps not closely similar to the sound of the pipes, but at least audible. It’s first recorded near the end of the fourteenth century, in Chaucer’s Canterbury Tales. In the Miller’s Tale it says (in modernised spelling): “Wafers piping hot out of the gleed”, where a wafer is a kind of thin cake, baked between wafer-irons, and gleed is the hot coals of a fire. > **[Piping hot: Origin of this sizzling phrase](https://www.worldwidewords.org/qa/qa-pip1.htm)** > > Why does 'piping hot' refer to temperature when 'piping' itself seems unrelated to heat? ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 22, 2008, 10:43pm UTC](https://boards.straightdope.com/t/ensure-product-is-piping-hot-before-eating-why/434574/10 "2008-01-22T22:43:24Z")
[QUOTE=Ferns] What _is_ “piping” anyway? [/QUOTE] Vigorously emitting steam, or being hot enough to do so, I’d say ---
**Author:** ![Terminus\_Est](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/terminus_est/32/3087_2.png) [@Terminus\_Est](https://boards.straightdope.com/u/Terminus_Est)\ **Post date:** [January 22, 2008, 10:54pm UTC](https://boards.straightdope.com/t/ensure-product-is-piping-hot-before-eating-why/434574/11 "2008-01-22T22:54:30Z")
If the food is hot enough that, when bitten into, one makes a sound like bagpipes, then it can be said to be “piping” hot. ---
**Author:** ![Hockey\_Monkey](https://avatars.discourse-cdn.com/v4/letter/h/a183cd/32.png) [@Hockey\_Monkey](https://boards.straightdope.com/u/Hockey_Monkey)\ **Post date:** [January 22, 2008, 11:24pm UTC](https://boards.straightdope.com/t/ensure-product-is-piping-hot-before-eating-why/434574/12 "2008-01-22T23:24:30Z")
[QUOTE=Colophon] The phrase “Ensure product is piping hot before eating” seems to pop up in the heating instructions of just about every convenience food, even things that you could happily eat cold, like baked beans or sausage rolls. Presumably most “cook chill” foods, like microwaveable curries, would also be perfectly safe to eat cold, and the heating is purely to make them more pleasant to eat. I wouldn’t be putting my health at risk by just warming it to tepid and tucking in, would I? So why this “ensure food is piping hot” spiel? Is it just to make sure we’re in the habit of heating all foods thoroughly so that we’re not caught out by things we actually do need to cook, or is there some other reason? [/QUOTE] I assumed it was so you would burn your mouth on the first bite and then not be able to taste how truly horrible the product really was.