February 3, 2014 at 2:38 pm #12934
I’m new to pressure cooking so I thought I’d try to get some advice here. My mother used her Fagor pressure cooker to cook some meat, beans, vegetables in a soup. Being in a hurry, after the desired cooking time, she put the pot in a basin of cold water and also turned the dial to quick pressure release. Not sure how long the total time was between cold water immersion and full pressure release, but after she opened the pressure cooker (no problems there), she took a spoon or ladle to check the meat, and immediately the food contents exploded (about 50% she said) and left her with 1st & 2nd degree burns on her face and arm!
She’s still recovering in the hospital, but perhaps someone here can explain to us why this happened. It seems like it was a combination of the superheated food and quick pressure release that led to a unique state of the food. I’ve read about superheated water exploding in the microwave after a teabag is put in, but it seems like the jostling of the pot in the cold water, quick pressure release, and opening the top would be enough “agitation” for the food not to be in this state. We’re all a little scared to use our pressure cookers now…February 3, 2014 at 2:55 pm #12937
First, let me say how sorry I am to hear that your mother was hurt – that sounds like a very scary experience!
Without knowing more about the recipe that was used, I cannot give you more details about what might have happened, except to say that thick and chunky food could have hot air pockets of steam that will violently come to the surface when the food is disturbed.
Manufacturers no longer recommend putting the base of the cooker in water (although they used to over 20 years ago). Your mother’s experience is probably one of the reasons why: VERY uneven cooling.
All of the Fagor pressure cooker manuals, under the description of the cold-water quick release, do not mention also turning the pressure valve. And there is also the following line in all caps: NEVER IMMERSE THE PRESSURE COOKER IN WATER
Speaking for myself, I have stopped calling for the cold-water quick release in all new recipes starting about two years ago. First of all it’s nerve-wracking for a beginner to walk around their kitchen with a pressurized cooker, the cooker can be easily damaged if cold water enters any of the valves and, more practically, because I write recipes that can be used in both stove top and electric pressure cookers.
Nothing I say can heal the physical and emotional scars endured by your mother.
But, if you should you ever consider pressure cooking again, carefully read the pressure cooker manual before you begin and heed the manufacturer’s warnings.
I hope your mother feels better, soon!
LFebruary 7, 2014 at 12:59 pm #12961
Thank you for responding, your explanations make sense. I do see that the Fagor manual recommends running cold water over it for quick release and not to fully immerse it in water. However, my Presto cooker manual says you can pour cold water or place it in a pan of cold water. So that’s what she did: placed it in a basin of cold water (not fully immersed). In fact, the Presto website FAQ
says you can place it sink full of cold water! But now knowing the dangers you explained, we won’t be doing either of those anymore!February 9, 2014 at 1:57 am #12968
I’m not personally familiar with the workings of the Presto – so I cannot comment on their advice and opening methods. As you know the pressure valve on the presto works completely differently than does the one on Fagor.
Even in Europe, they USED to say to put the base of the cooker in a sink filled with water (but not high enough to cover the lid) – I believe that was the advice doled out on the Modernist Cuisine Website, too – and it came from a French Chef. But the Swiss pressure cooker that they photograph and video actually advises against it. I haven’t looked carefully at all of their recipes but I noticed they also recommend some other not-so-safe things to do with your pressure cooker (like boiling oil in a jar and then opening the cooker with the quick release – which could cause the pressurized jar full of hot oil to explode).
My point is this: even professionals make a mistakes.
What is important is to become familiar YOUR pressure cooker’s workings and safety warnings. It can get quite complicated if you have several brands.
My advice on this website (and my book) has always been: that if there is ever a disagreement between what a book, online recipe, French chef or great aunt Bertha tells you to do with your pressure cooker and what is written in the manual that came with it… the manual wins. Always.
Especially because of what happened to your mother, I would add to just not do any more quick-releases with either pressure cooker. Use only the Natural and Normal Pressure releases – according to each cooker’s instructions.
I hope your mother is feeling better, and back home!
LFebruary 9, 2014 at 12:43 pm #12974
Thank you for taking the time to answer my questions. My family and I now have a better understanding of why this happened and what can be done to prevent accidents in the future. Mom is doing much better now, thanks. We really appreciate your advice!February 9, 2014 at 1:38 pm #12975
I wonder if it could have been the same thing that happens when you microwave liquid. I have heard warnings against pulling a hot liquid from the microwave and stirring it or it can explode.
I have experience it to some degree myself, with water popping from the container I heated it in.
terry r.February 12, 2014 at 7:08 am #13035
Don’t try to get all the steam pressure released in an instant. Releasing 15 psi of steam pressure too quickly will result in sudden eruptions like this.
I know it’s easy to want things in life done instantly, but please allow the pressure to release at its own speed. It takes less than a minute to release all the steam when turning the dial. The “natural” release will take longer, which is why it’s used to finish cooking the food e.g. meat joints.
As for the cold water release: DON’T DO IT! There’s no need to do the cold water release.February 23, 2014 at 3:38 pm #13242
What Terry said. It was almost certainly “nucleation.”
Here’s what I have written about nucleation elsewhere:
The “myth” that water can explode in a microwave is actually true.
The process of bubbles forming in water is called “nucleation”. It occurs when water molecules break apart, releasing gas. This happens at the bottom of pots or kettles, where the heat source is concentrated.
Water in a microwave can heat up to its boiling point without bubbles forming, thus, it doesn’t appear to be “boiling.” In fact, microwave heating allows water to “superheat” past its boiling point.
But, when the water is finally moved or disturbed in some way, such as adding something to it or putting a spoon in, nucleation occurs all at once and the water appears to “explode.”
To avoid this, keep zapping the water in the microwave until it actually does boil for 5 to 10 seconds.April 5, 2017 at 8:19 am #100224
“To avoid this, keep zapping the water in the microwave until it actually does boil for 5 to 10 seconds.”
That is not sufficient, because water in the microwave can explode without being stirred.
We once were heating water in the microwave. Suddenly, the microwave door flew open, hard! And water was everywhere. I could never have imagined how wet a room could get (floor, ceiling, walls, everything) from a cup or two of water! We’ve always been very grateful that no one was standing in front of the microwave, since the door opened with a huge bang and it would have really injured someone who was standing in front of it.
So we no longer boil pure water. We prefer to put something else in the water, maybe sugar or salt or a bean or something. Mainly, I heat water to boiling on the stovetop.April 9, 2017 at 10:35 pm #101195
First off, I’m very sorry to hear that your mother was burned so badly. I’ve worked in kitchens and both been burned myself and seen other people burned and… well, burns are no fun at all. I wish your mother the best.
Modern pressure cookers are very safe, but their contents are not necessarily so, especially when pressure has just been released. The point of pressure cooking is to heat liquids and steam to a temperature that would be impossible at normal atmospheric pressure. This poses two dangers, and it is important to be aware of both.
The first is that the contents are just hotter than you are generally used to. The difference between 250 F and 212 F might not seem that significant, but it really is- that’s why pressure cookers cook things so much more quickly. Even regular steam at sea-level is very hot. I remember my mother once burning herself very badly taking a lid off a normal pot, and having her hand caught in a blast of steam. She wound up with an enormous blister, and had to go to the ER. Steam is worthy of respect, and it is all the more so when it is super-heated.
The second is that the contents of a pressure cooker may cool at different rates in different places, especially if they consist of a large volume of liquid that doesn’t circulate easily. It’s possible for pockets of liquids to stay hotter than they can be at normal atmospheric pressure, and they can be very volatile if you suddenly mix them with much cooler liquids.
When you immerse the base of a cooker in water you run the risk of creating just that situation. The contents against the walls of the cooker will cool very quickly, but the contents toward the center will remain very hot. If you also release pressure through a valve you just exacerbate the situation. When, having created a very sharp temperature gradient through the contents of the cooker you then violently stir the contents together… dangerous things can happen.
There are a few simple rules that will avoid this sort of danger:
1) If you want to quick-release a stove-top cooker do so by running cold water over the _top_ of the cooker, not by placing its base in water
2) Don’t mix the above quick release with valve release. Pick one.
3) Be very careful of the steam coming out of your cooker. Steam at 212 F can burn you badly in an instant. Steam at 250…
4) Whenever you do a quick release of any kind when cooking a large volume of liquid leave the contents of the cooker alone for at least a couple of minutes after opening it. The more viscous the liquid you are cooking the longer you should let it sit. I _never_ mess with any large volume of liquid in a pressure cooker until it has at least stopped bubbling, but with viscous stuff I’ll wait a few minutes more.
Pressure cooking is like any other sort of cooking- fairly safe if you understand it well, dangerous otherwise. As a young man I used to come home from parties a little drunk and make french fries in a small shallow pan- not sure what I was thinking there, but it’s a miracle it never ended badly.
Pressure cooking is quite safe, if you understand it, but, like most other techniques, you really do have to understand it well for it to be completely safe. Heating liquids to such high temperatures does sometimes lead to some un-intuitive results.January 8, 2018 at 7:08 am #588259
To the original poster, and anyone who happens to still be following this topic, I wanted to let you know that I’ve heard of enough cases and understand the phenomena that caused this “exploding food” enough to issue a consumer alert on the subject.
Specifically, I was triggered into action when I saw some posts on Facebook of people with injuries that were shared by concerned people to pages and groups containing disgusting replies that included victim-blaming (user-error, you’re lying, etc.) and totally inaccurate explanations about how something like this could happen (equipment failure, damaged gasket, not possible etc.)
Here is the alert:
Instant Pot has taken the lead and shared this link pinned to their Facebook community and homepage for a day (yesterday). Additionally, I have personally contacted all the manufacturers that I consult with, along with several large ones I don’t (Power Pressure Cooker, Elite, Cuisinart, Crock-pot and Aroma), to encourage them to research this issue independently, inform their customers, and review the recipes in their manuals, websites, apps and youtube videos to ensure that they do not include this defect (thick and fatty recipes).
Let’s all work together to ensure there are no more new injuries, like the ones suffered by this lady’s mother and others, to our fellow cooks.
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