Autoclave Vs Pressure Cooker: Which Is Better?

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Pressure cookers and autoclaves (also referred to as steam sterilizers) are two of the most common devices used for sterilization. Whether you need to disinfect foods, baby bottles, or lab materials, these appliances can suit your needs.

However, if you’re looking to purchase one over the other, you may be wondering which does a better job at sterilization. In this post, we will look at some of the similarities and differences between the two machines so that you can make an informed decision.

What is Sterilization?

When dealing with food, laboratory, or hospital equipment, it’s important to take steps to remove microorganisms from objects. This is all that’s meant by the term sterilization. Sterilization can be achieved at temperatures beginning at 121 degrees Celsius combined with a pressure of at least 15 PSI. 

Steam is ideal for sterilizing due to its ability to transmit heat consistently and surround and penetrate the object. Both pressure cookers and autoclaves destroy microorganisms by increasing the boiling point of water via steam pressure, and both are cylindrical to be able to withstand the high pressures created.


In general, autoclaves are the preferred tool for laboratory or hospital settings. You might consider them to be a more “serious,” heavy-duty version of a pressure cooker. 

The name “autoclave” means self-sealing and refers to the fact that the pressure creates an “automatic” lock, though it’s important for there to be external, manual locks as well. Vacuums are created within autoclaves, either by removing the air with a vacuum pump (pre-vacuum) or by pumping in steam to displace the air (gravity displacement). 

Within the category of autoclaves are two subcategories: electric autoclaves and non-electric autoclaves. 

Electric autoclaves are great for sterilizing objects that need to be completely submerged, like syringes or thermometers. Non-electric autoclaves, on the other hand, don’t use much water, instead sterilizing through dry steam. This makes them ideal for cleaning porous objects or any objects which are especially frail.

Pressure Cookers

Pressure cookers generally can’t reach the same high temperatures as autoclaves. They are not as effective as autoclaves when it comes to sterilization, though they still can do a reasonably good job. 

One of the major differences between an autoclave and a pressure cooker is that pressure cookers do not create a vacuum – therefore, you’ll need to let it build pressure for a certain amount of time before using it for sterilization. The fact that pressure cookers typically operate at a much lower PSI than autoclaves also means more sterilization cycles will be required. 

So what are the benefits of opting for a pressure cooker? One benefit will be, of course, the lower price. Whereas smaller autoclaves can be around $1000, pressure cookers can cost as little as $100. In addition, you may already have a pressure cooker available.

They’re also going to be much easier to transport from site to site, so if you want to sterilize food while on vacation or are doing field research, a pressure cooker makes more sense.

So Which One Is Better?

Overall, autoclaves do a better job at sterilization than pressure cookers do. However, they can be prohibitively expensive. If you have a lot of extra money, or are very serious about getting involved with something like mycology or lab work, then you should consider investing in an autoclave.

If you just want to sterilize the occasional canning dish or a baby bottle, a pressure cooker should be more than enough to meet your needs. Keep in mind, though, that they need to reach a certain PSI in order to sterilize properly, so be sure to check the maximum PSI of the brand you’re going to buy.