Grow mushrooms the EZ way.

Instant Pot For Mushroom Cultivation

I was shocked when I realized how useful a Instant Pot could be for growing mushrooms.

This is because the Instant Pot and similar “electric pressure cookers” operate at 12 psi instead of the 15 psi which is the gold standard required for grain jar preparation. 

I assumed that this meant they wouldn't be very useful, however after purchasing one myself and trying it out I realized it can be used for sterilization, pasteurization and keeping agar warm!

Instant Pot Tek is definitely useful for small-scale mushroom cultivation project at home, such as sterilizing PF-tek jars , making liquid culture jars and small grain spawn jars as well as pasteurizing substrate.

However, those who are serious about mushroom cultivation may want to consider alternative options.

I have written a full post on pressure cookers which I would recommend checking out as well.

Instant Pots are very popular and more readily available to some individuals than stove top pressure cookers.

Along with the use cases discussed below it may be a convenient choice for home mycology.

In this post, I will discuss how to use an Instant Pot for mushroom cultivation and provide some tips for success.

Choosing An Instant Pot For Mushroom Cultivation.

Realistically you are going to want to go with the largest model possible that would be the Instant Pot Duo 8qt / 8L model. I have chosen this because it will fit the most amount of spawn jars or substrate in it at one time.

Instant Pot 8Qt

Instant Pot for mushroom cultivation
  • 12 PSI.
  • Capacity 7 x 0.35L Jars.
  • Sterilize Setting.
  • Pasteurize Setting.

This model can fit 7 X 0.35 Litre wide mouth mason of jars inside. Which is plenty of spawn for a beginner or casual grower.

Alongside this a full monotubs worth of substrate could be pasteurized easily.

7 small jars in an Instant Pot

Pros Of Using An Instant Pot.

  • Widely available.
  • Safer product than conventional pressure cooker.
  • Precise pasteurization temperatures.
  • Does not require a stove.

Cons Of Using An Instant Pot

  • Small Size fits less jars.
  • Low pressure cooking temperatures.
  • Expensive (compared to a pressure cooker).

Using an Instant Pot For Mycology

Can You Use An Instant Pot To Sterilize Grain Jars?

Yes, it is possible to sterilize grain spawn in an instant pot; it just takes longer than a conventional 15 psi pressure cooker.

Prepare your grain jars using the methods I discuss in how to prepare grain spawn.

  • Place the jars in the instant pot.
  • Press the “Pressure Cooker” button
  • Set the desired time (3 hr).
  • Set the tempreture to HIGH.
  • Put the lid on.
  • Press the start button.
  • Allow to cool over night once complete.

There are several ways you can use an Instant Pot for mushroom cultivation:

PF-Tek In Instant Pot.

The PF-tek method can be performed reliably using an instant pot because it is especially forgiving for those new to mushroom cultivation. 

Using an instant pot, you can easily sterilize your PF-tek mixture and ensure a successful grow.

For a fully guide read using a Instant Pot for PF-tek.

In short, follow the normal PF-tek procedure, then sterilize your jars in the instant pot's pressure cooker on the high setting for at least 2 hours.

To do this press the “Pressure Cooker” button, input the 3 hours time and ensure the highest setting is selected.

Put the jars in the cooker then click start.

A full Instant Pot Tek can be found on PF Tek for growing mushrooms.

Making Liquid Culture In an Instant Pot.

To sterilize a liquid culture using an instant pot:

  • Set the appliance to the high pressure setting (12 psi). 
  • Fill the pressure cooker with 3 quarts of water.
  • Place the liquid culture (e.g, 500 mL) inside the instant pot and run it for 30-40 minutes. 
  • Turn the “keep warm” setting off.
  • After the sterilization time has elapsed, allow the pressure cooker to cool down for a few hours before opening it.
  • This will allow the temperatures inside the jars to stabilise before exposing it to the non sterile environment. 

This process should effectively sterilize liquid culture.

Sterilizing Small Grain Jars In an Instant Pot.

Although the instant pot has a lower pressure setting (12 psi) than some other pressure cookers (e.g., 15 psi), it can still be used to sterilize grain jars. 

To sterilize small grain jars  in an instant pot, use the pressure cooker setting on high. 

Run the instant pot for at least 3 hours to sterilize the grain jars. 

After the sterilization time has finished allow the pressure cooker a few hours to cool before removing jars.

Pasteurizing Substrate Instant Pot Tek.

I find that using my instant pot to pasteurize substrate is a convenient, clean and simple method.

To do this, I simply fill the instant pot with my bulk substrate and water, and set it to the keep warm setting (medium setting). 

This will maintain a temperature of between 140-172 degrees Fahrenheit, which is ideal for pasteurization. 

Alternatively, I can use the sous vide setting and set the temperature to within this range.

After allowing the bulk substrate to pasteurize for approximately 2 hours, it is ready to be used for spawning to bulk.

A full guide can be found in how to sterilize mushroom substrate without a pressure cooker.


The instant pot isn't perfect for sterilization but it is definitely a useful tool to have for home mycology.

It can keep precise pasteurization temperatures for hours on end without you having to worry whether the house might burn down.

It can sterilize grain jars, albeit slower than a 15 psi pressure cooker, but once the timer is finished it turns itself off so you don't have to worry about missing it.

The safety of using an instant pot in comparison to a conventional pressure cooker can not be understated and I find myself using it more and more.

I hope this information has helped you understand how an Instant Pot can be implemented for mushroom cultivation.

Please checkout our recommended equipment section or our latest post below.