The Best Ways To Sterilize Mushroom Substrate (2024)

Sterilizing mushroom substrate prevents the mushrooms from becoming contaminated. Finding the right sterilization process is important if you want a batch of healthy mushrooms. Learn some of the best ways to sterilize mushroom substrates.

Microwave Sterilization

This form of sterilization requires you to microwave your substrate. This method is perfect for someone just beginning their cultivation journey. That said, you need to be careful because it is a fire risk. Fortunately, you don’t need much to prepare for this method; just a microwave, a bowl, and the substrate.

Put the substrate in a clean, microwave-safe container. Then, microwave the substrate on high for 5–12 minutes. You should only use this method with a small amount of substrate.

Fermentation Method

This method is perfect for bulky substrates like straw, wood, or coffee grounds. It’s one of the best ways to sterilize mushroom substrate and is perfect for anyone growing mushrooms and for fast-growing varieties. You must submerge the substrate in water for a week, which lets good bacteria grow. Over time, organisms that need oxygen to live will die off, and the good bacteria will thrive.

Pasteurization Method

Pasteurization is ideal for substrates consisting of low-mass materials like hay. This method is also ideal for mushrooms that grow quickly and for beginning cultivators looking to advance their craft.

When you pasteurize your mushrooms, you use temperatures much lower than sterilization, so it’s easier. However, it takes longer and doesn’t kill all the organisms within the substrate but rather allows beneficial microorganisms to live. Any science student or experienced cultivator can tell you that beneficial microorganisms are important for the growth of mycelium, so nurture the growth of these microorganisms.

At Midwest Organics, we can help you if you need commercial enclaves and pressure cookers for your sterilization purposes and mushroom grain jars to begin your cultivation journey. Contact us today to pick up one of our mushroom grow kits!