Pressure cooker making a hissing sound Any idea what happened? It only did this one time, and not sure what I did wrong.

  • what were you/it doing at the time?
    – Esther
    Sep 1, 2022 at 20:26
  • 3
    What type, age and model of pressure cooker were you using? The earlier generations of pressure cookers will make a hissing sound when coming up to pressure and intermittently during cooking as well. The newer models are a lot quieter, some will barely hiss at all.
    – Greybeard
    Sep 1, 2022 at 21:59
  • There are two main types of regulators: ‘jiggling’ ones that that will give off steam when they get up to pressure (keeping it from over pressurizing) and ones that seal once they’re at pressure, but have some sort of a fail safe to vent when they’re too far past pressure. So the first one hissing is good. For the second, it’s a sign that it’s not yet to pressure (or significantly over pressure, but that should be more than a slight hiss)
    – Joe
    Sep 3, 2022 at 13:30

1 Answer 1


It's normal to hear hissing from a pressure cooker, in fact it's a sign it's working. When you heat a pressure cooker the water inside turns to steam, which is captured by the seals to increase the pressure inside the vessel. Once the pressure reaches a certain point a valve will open to let some of the steam escape so the higher pressure is maintained at a constant level. If this valve didn't work then your pot could rupture if it's a very old one, so it's a very important safety feature for older cookers. Modern pressure cookers have redundant safety features like pressure plugs to ensure safety.

Note that lack of a hiss doesn't always mean you are in imminent danger, usually it's a sign you don't have a good seal rather than a bad valve. I would suggest you track down the hiss, if it's coming from the valve then it's normal operation, if it's coming from around the lid then it's not sealed properly. When tracking the hiss down remember it's steam escaping and be careful not to burn yourself. If you can't see where steam is escaping you can use a big spoon to detect it rather than your ear, or a mechanic's trick is to use a short piece of hose or straw as a stethoscope.

  • 1
    To be clear, on a modern pressure cooker there’s about three separate failsafes to prevent an explosion. There is no need to be afraid of a pressure cooker that is not (yet) hissing.
    – Sneftel
    Sep 2, 2022 at 9:32
  • That's true @Sneftel, I am not assuming this is modern but it's worth an edit.
    – GdD
    Sep 2, 2022 at 9:36

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