There is a spate of Facebook posts making the rounds from people using varying brands of stove top and electric pressure cookers, detailing multiple accidents where the cook is burned by a violent eruption of food after the lid is removed. Similar accidents can be found in the U.S. Consumer Product Safety Commission Safer Products Database and on this website.
There is a very real concern that the redundant safety systems in the pressure cooker’s lid have failed to protect customers.
However, all of these accidents have these things in common:
- The recipe was “thick” (beans, soup, chili, stew) and the pressure was released using a very fast opening method (Normal/Quick/Water).
- The recipe was “fatty or oily” (soup, meat stock) and the pressure was released either quickly or using a natural release.
- The safety lock did not prevent the cook from easily opening and removing the lid.
We want to assure our readers, that the cause of these types of accidents is not a failure of the equipment or user-error – unfortunately, it is badly written recipes.
This is What’s Happening
There could be two causes for a “violent food eruption” after pressure cooking is finished and the lid is removed.
When a recipe is thick and viscous, it cannot easily boil and generate bubbles to release the steam. When a very fast pressure cooker opening method is used for this kind of recipe, the steam is released only from the very top of the recipe and the safety systems are disengaged because no more pressure is detected inside the cooker. However, there could still be a bubble of super-heated steam held under the thick food that has not yet broken to the surface during the release – this bubble could come to the surface even several seconds after the lid is removed.
When a recipe contains large amounts of fat and oils (added as part of the recipe or released from fatty meat), the high temperatures of pressure cooking turn this fat into oil. Since oil is lighter than water, it can rise to the surface and form a film that will prevent some of the heat from the liquid below from evaporating – even after the lid is removed. A disruption of this film, with a utensil, or bump of the cooker, can release this unevaporated heat all at once – creating a situation similar to the infamous exploding microwave water.
Both of these, are known phenomena and some manufacturers include precautions in their instruction manuals on how to avoid it.
Spot & Avoid Recipes For Disaster
The internet has made it incredibly easy, and exciting, for anyone to share pressure cooker recipes at the push of a button. Unfortunately, the recipe author may not be aware of how the pressure cooker works – which is why it’s important to only follow recipes from trusted sources.
Here’s how to spot a recipe that could lead to an unexpected eruption after the lid of the pressure cooker is removed:
- Read your pressure cooker manual, and pay special attention to the list of foods to avoid pressure cooking such as oatmeal, applesauce, pasta and split peas/lentils – some of these can be pressure cooked safely following specific precautions such as: pressure cooking oatmeal in a bowl, ensuring pasta has absorbed all of the cooking liquid, and specific cautions for split peas (noted here). In addition, do not pressure cook hard liquor – more on this in an up-coming alert.
- Never overfill the pressure cooker – follow the filling guidelines detailed in the manual: no more than 1/2 full for beans, rice and grains and no more than 2/3 full for everything else – here are more details on this.
- Avoid recipes that include steps for thickening or use thickening agents before pressure cooking (they can be simmered-in afterward). These include:
- instructions for pureeing ingredients before pressure cooking,
- adding flour, starch, gum before pressure cooking, and
- prepared ingredients such as soup/salad dressing/meat flavoring packets, condensed soup cans, jars of commercially produced sauce.
- Don’t use more than a 1/4 cup (4 tablespoons) of oil, butter or fat to a pressure cooker recipe – you can always add more after pressure cooking.
- When making soups or stocks with fatty meats, release pressure according to the recipe and then gently shake or tap the pressure cooker on the counter BEFORE removing the lid.
- Do not open the pressure cooker containing a thick recipe (such as a chili, soup or stew) quickly using a Normal, Quick, or Cold Water release. Use slow normal, 10-minute natural or natural release – here’s how.
- Never force the lid of the pressure cooker open – it should open as easily as it closed. If there is any resistance make sure the valve is in the position to release pressure and wait for the lid-locking mechanism to disengage.
Please note that some manufacturer’s own recipes published in their recipe books or apps, may also contain these defects – we also spotted at least one with these defects in the pressure cooker cookbook of a famous Test Kitchen TV Show.
Pressure cooking is a safe cooking method, but please follow recipes from trusted sources and, most importantly, heed the warnings in your cooker’s instruction manual.