Does Mushroom Growing Medium Need to Be Sterilized?

Sterilization of mushroom growing grains and substrates, what you need to know.
In order to understand the importance of sterilization in modern mushroom farming, you must see the benefits of sterilization. It is important to sterilize your grain spawn material and your mushroom substrate.

The first benefit of sterilization is that it kills the fungus and bacteria that may be in your grain spawn. This is the most common reason why you need to sterilize your grain spawn. If you don’t sterilize your grain spawn, the fungus will grow in your spawn. This will cause a lot of problems for your mushroom crop. For example, your mushrooms will be small and have a bad taste. If you don’t sterilize your grain spawn, it can also cause you to lose your crop. The fungus can grow on your spawn, and you can end up losing your entire crop.
You should know that it is very important to sterilize your substrate, because you don’t want to have the mushroom grow on a contaminated substrate. You want to have a clean, healthy environment for the mushrooms to grow in.

It’s important to sterilize your substrate in order to prevent the contamination of the mushrooms with bacteria and other organisms. If you are interested in growing mushrooms, and would like to get started, then you will need to know how to sterilize your grain spawn.


Choose Your Level of Sterilization Equipment

Entry Level Sterilizer
Mushroom Grade Sterilizer
Pro Grade Sterilizer
Sterilizing Grain Spawn

How to sterilize your grain spawn?

There are several ways to sterilize your grain spawn. The first way is to use a solution called a steam sterilizer. A steam sterilizer is equipment that will heat up water to a high temperature. Steam sterilization works best when it is also pressurized. This can be in a sterilizer like the All American brand or, for professionals, a mushroom autoclave.

Another way to sterilize your grain spawn is to use a dry heat sterilizer. A dry heat sterilizer is the least effective way to sterilize your grain spawn. A dry heat sterilizer is similar to a steam sterilizer. It has a chamber that is filled with heated air. The heated air will kill any fungus or bacteria that may be in the chamber.

What other options are available?

What alternatives do I have if I can’t afford a mushroom autoclave?

We understand that you may not be ready to invest in an autoclave yet. The next best alternative is the All American Sterilizers. These are commercial quality units built to last, with safety in mind. The All American are also available in large sizes up to the 41 quart model. These are available in 120V and 240V models.

How much grain spawn can I process per cycle?

How much grain spawn can I sterilize per cycle?


The amount of grain spawn you can sterilize depends on the internal size of each sterilizing unit. Our largest capacity mushroom autoclave sterilizers can sterilize up to 128 lbs. of grain spawn or substrate in one cycle. These units are also rapid to heat up and reach pressure. They can reach the internal heat and pressure required in just 19 minutes.

Other smaller units like pressure cookers might take 30 minutes or more just to get up to temperature and pressure. They also can not typically reach the pressure and temperature range that a mushroom autoclave can.

It is important to remember that mushroom cultivation related sterilization is an off label use of most pressure cookers. You must be very careful when using them for this purpose.

How do I chose a sterilizer?

How can I choose the unit that is right for me?


Choosing the proper sterilization unit for your farm is all about where you are in the growth of your business. Just like any other investment. Purchasing quality sterilization equipment is an investment in your business. There are few tools you may buy that will have as much positive impact on prevention of contamination, and the quality of your resulting mushrooms.

By preventing contamination, you increase your yields, appearance, and taste of your mushrooms. This means you stand a better chance selling to restaurants and chefs, grocers, and even directly to the public. Investment in a mushroom autoclave or All American Sterilizer along with a great flow hood are key purchases to consider.