Which Electric Pressure Cooker Operates at 15psi?

Because most pressure cooker recipes are designed for 15psi pressure cookers. Many users are looking for 15psi electric pressure cooker.  We are asked whether Instant Pot operates at 15psi.

To answer this question, we need to clarify a concept here.  The max working pressure of a pressure cooker is the pressure which pushes up the safety device (i.e. steam release, pressure valve or by some other names) and the cooker starts letting out steams to reduce pressure. The max working pressure of stove-top pressure cookers ranges from 12psi to 21.7psi. For the high-end stove-top models, it is typically in the 16~21.7psi range. This is specified in product document and also commonly marked at the bottom of the steam release.

Instant Pot has a max working pressure of 15.23psi (105kpa). This is marked on the steam release handle, see the image on the top.  One of the design objectives of Instant Pot is not to let out steam and make noise during its operation.  So normal working pressure has to be below 15.23psi.  Instant Pot’s working pressure is in the range of 10.15~11.6 psi. If you have small amount of food/liquid in the cooker, Instant Pot may touch 15.23psi momentarily due to the heat conduction delay.

When a stove-top pressure cooker reaches its max working pressure  and starts whistling out steams, you’d turn down the heating to stop the whistling.  In such a condition, your stove-top pressure cooker may be operating at a pressure level similar to Instant Pot. You only cook the food at the max working pressure when it’s whistling continuously.

So,

  • Does Instant Pot have the same 15 psi max working pressure as common stove-top pressure cookers? Yes! It’s 15.23psi.
  • Does Instant Pot cook your food constantly at 15psi? No, it’s in the range of 10.15~11.6 psi.

Illustration of Instant Pot working pressure curve

You can see the working pressure chart on the right. Most electric pressure cookers available on the market work like this, but may not have the same max and working pressure range.

If your recipe specifies cooking at 15psi, you can adapted to Instant Pot by increasing the cooking time by 7~15%.

Note: the max working pressure is not an indicator of the max safety pressure that the cooker can withstand. If a cooker is certified with UL or equivalent, it should withstand 5 times the working pressure without leaking.

Many electric pressure cooker has a max working pressure of 13.05psi (90kpa).  You can find this out by looking at the bottom of its steam release.  A properly certified and manufactured cooker always has such rating on the parts.

 

19 replies
  1. Sue
    Sue says:

    I’ve been using my Mom’s stovetop pressure cooker since I was a teenager (MANY years ago). To give you an idea of the age of said cooker, it was a wedding gift in 1946. Most of the recipes I’ve used in the booklet that came with it call for 10 psi. How do I convert those recipes for use with my Instant Pot IP-DUO Plus?

    Reply
    • mjun
      mjun says:

      Instant Pot operates at 11.6psi. How fast food cooks depends on the temperature of cooking. The cooking temperature of 15psi pressure cookers is 121ºC (250ºF); whereas, the operating temperature of an 11.6psi Instant Pot is 117°C (242°F). This is a difference of 3.4%. We find in most cases recipes for 15psi pressure cookers can be adapted to Instant Pot by increasing the cooking time by 7~15%.

      Reply
  2. Paul Rathgeber
    Paul Rathgeber says:

    What about pressure canning meat? that typically does in fact require the higher pressure for safety can your product safely do this?

    Reply
  3. Daniel
    Daniel says:

    It is a bit more complicated, the pressure of the device is the differential pressure between the working pressure of the device and atmospheric pressure, the real pressure (and boiling temperature) will change with the atmospheric changes, modifying cooking times (e.g. cooking in Mexico City) while the working pressure remains the same.

    Reply
    • mjun
      mjun says:

      Hi Dr.Ricardo Gomez,
      Our pots do not get to high enough temperatures to work as common autoclaves, which require a minimum of 249F.

      Reply
  4. Nick
    Nick says:

    I keep seeing #’s like this floating around and they make no sense to me. Normal atmospheric pressure at sea level is 14.7 PSI. That means a electric pressure cooker working at 10-11 PSI would be operating at a *lower* pressure than ambient, not higher! So when you say 10-11 PSI you really mean above ambient atmospheric pressure – i.e, in the range 24.7 – 25.7 PSI?

    Reply
    • mjun
      mjun says:

      While you’re correct about normal atmospheric pressure at sea level, pressure cookers operate as if ambient air pressure starts with a base of 0. This is largely for standardization purposes, and why electric pressure cookers operate at 10-12 psi while stovetop cookers operate at 15 psi, across the board.

      Reply
    • Tom
      Tom says:

      If you let all the air out of your car or bike tires, you will see the pump or gauge reads 0 psi. So obviously the standard way to use PSI is as a relative measure, above and beyond ambient pressure. It’s simpler and easier to understand.

      Reply
    • Anthony DeRobertis
      Anthony DeRobertis says:

      There are two ways of specifying pressure, either absolute (psia, pressure above true vacuum) or gauge (psig, pressure above ambient air pressure). Ideally everyone would always be clear which they’re using, but in practice many things are in psig without specifying. Including pressure cookers (and tire pressures, gas burner pressures, household water pressure, and honestly most everything outside of science.)

      Probably the most common absolute pressure measurement you run in to (outside science) is a weather report—those pressures are obviously absolute, it’d hardly make sense to report it vs. ambient air pressure, because the answer would always be 0. (Of course, weather reports are seldom in psia, but rather mmHg, kPa, etc.)

      Reply
    • K Moore
      K Moore says:

      Like when you are inflating a tire on a vehicle, like a car. The atmospheric pressure is not considered. The recommended pressure references the internal pressure of the tire or in this case the pressure cookers operating pressure.

      Reply
    • Stuie
      Stuie says:

      Nick, this is solid logic, maybe you should also consider being an engineer. The absolute pressure, (psia, or Pounds Per Square Inch Absolute) would include ambient atmospheric pressure at the time the measurement was taken + the pressure inside the cooker. So the pressure cooker absolute pressure would be ~14.7psi + 11psi = 25.7psia.

      The pressure on the gauge is relative to the ambient atmospheric pressure. The gauge zeroed out at atmospheric pressure–so the pressure starts at 0 as you look at the gauge in your home. The unit of measurement for this (in the United States) is called psig or Pounds Per Square Inch Gauge.

      Most of the time, psig is shortened to just psi–as psia would only be relevant if you were pressure cooking in outer space.

      Reply
    • Max Peck
      Max Peck says:

      It’s the difference between absolute vs. gauge pressure. Absolute pressure (psia) is pressure relative to an absolute vacuum. Gauge pressure (psig) is pressure relative to ambient environmental pressure. In the context of pressure cookers any reference to psi is assumed to be psig. This means technically the absolute cooking pressure will be different if you use the instant pot in Denver vs. sea level.

      Reply
        • Paul
          Paul says:

          No.

          The temperature at which water boils is directly proportional to the absolute pressure inside the pressure cooker. If you use a 10PSIg pressure cooker at sea level, the absolute pressure in the pot will be about 24.7PSIa and the temperature in the pot will be 240°F

          But if use the same pressure cooker in Denver (where atmospheric pressure is about 12PSIa, the absolute pressure in the pot will be only 22PSIa and the temperature will be 233°F. But the gauge on the pot will still show 10PSIg!

          At higher elevations (like Denver) one needs to increase cooking times to make up for the lower temperature. For canning, where specific minimum temperatures are required for safety, higher pressures are required for high elevations. (BTW: The Instant Pot products are NOT suitable for pressure canning.)

          PSIg means “Pounds per square inch measured at the gauge on the device”.
          PSIa means “Pounds per sqaure inch, absolute pressure”
          A pure vacuum is 0PSIa.

          Reply
    • jim
      jim says:

      The pressure in the pressure cooker is referred to as gauge pressure. Absolute pressure is the gauge pressure plus the atmospheric pressure. So 10 psi in the pressure cooker is 10 psi gauge or given a atmospheric of 14.7 at sea level would be 24.7 psia, (absolute)

      Reply

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