Grow Oyster Mushrooms Easily at Home: A Beginner's Guide to Inoculated Spawn Method

Grow Oyster Mushrooms Easily at Home: A Beginner's Guide to Inoculated Spawn Method

Growing Oyster Mushrooms Easy, Abundant, and Affordable!

Are you a beginner in the mushroom-growing journey? Are you looking for a simple way to grow delicious and nutritious mushrooms at home? Well, growing oyster mushrooms from inoculated spawn is an excellent approach to start with. Here are some benefits of this method for beginners:

🍄 Easy to Grow: Oyster mushrooms are one of the easiest mushroom species to grow. They don't require complex growing conditions or specialized equipment, making them an excellent choice for beginners.

Keep in mind that the best substrate material for you will depend on your specific growing conditions and preferences. Experimentation is key to finding what works best for you.

🍄 Abundant Harvest: Oyster mushrooms grow fast and produce abundant harvests. With just a little care, you can enjoy a bountiful crop of these delicious mushrooms in a few weeks.

🍄 Versatile: Oyster mushrooms are versatile and can be used in various dishes, from stir-fries to soups and salads. Check out our Oyster Mushroom Recipe Blog Post for some delicious recipe ideas.

🍄 Affordable: Growing your mushrooms from inoculated spawn is an affordable way to get started in mushroom cultivation. You don't need to invest time and money in fertilization equipment like pressure cookers, spawning supplements, spores, etc.

To grow oyster mushrooms from inoculated spawn, follow these basic steps:

Choose a substrate material:

Oyster mushrooms can grow on a wide range of substrate materials, including straw, sawdust, and coffee grounds.

Substrate Material




Cheap and widely available

Can be difficult to work with. Sometimes comes very dirty.


High yield potential, easy to work with

Potentially mixed with several trees like pine trees which are not good for mushrooms

Coffee Grounds

Easily accessible

High risk of contamination, some argue it renders low yield

Hardwood Chips

Easy to work with

Requires extra sterilization, may need supplements for optimal growth


Sterilize the substrate:

Sterilizing the substrate material is essential to ensure that no undesirable microorganisms are growing alongside your oyster mushroom mycelia. Technically you are actually pasteurizing or partially-sterilizing as you want to kill bad bacteria while keeping beneficial ones alive.You can use a pressure cooker or a hot water bath to sterilize the substrate.

  • Pressure cooking is a popular method as it can quickly sterilize the substrate material, usually within 90 minutes at 15psi, by exposing it to high temperatures and pressure.
  • On the other hand, a hot water bath involves soaking the substrate material in hot water for several hours, which can also effectively kill off unwanted microorganisms. 
Substrate Method Temperature Time Ease of use
Straw Boiling 80-100°C (176-212°F) 1-2 hours Easy
Sawdust Pressure Cooking 121°C (250°F), 15psi 2-3 hours Moderate
Coffee Grounds Oven 150-180°C (302-356°F) 1-2 hours Easy
Hardwood Chips Steam 100-120°C (212-248°F) 2-3 hours Difficult


Boiling Straw:

Boiling is one of the easiest and most popular methods for sterilizing straw. To start, fill a large pot with water and bring it to a boil. Add the straw to the boiling water and let it cook for 1-2 hours. Make sure the straw is fully submerged in the water to ensure even sterilization. After boiling, drain the water and let the straw cool before using it as a substrate.

Pressure Cooking Sawdust:

Sawdust is a common substrate for oyster mushrooms, and pressure cooking is an effective way to sterilize it. Add sawdust to a bag and seal it, making sure there is enough room for expansion. Place the bag in a pressure cooker and cook at 15 PSI for 2-3 hours. After cooking, let the bag cool before using it as a substrate.

Oven Sterilization of Coffee Grounds:

Oven sterilization is an easy method for sterilizing coffee grounds. Spread the coffee grounds evenly on a baking sheet and bake them at 150-180°C (302-356°F) for 1-2 hours. Make sure the coffee grounds are spread out thinly to ensure even sterilization. After baking, let the coffee grounds cool before using them as a substrate.

Steam Sterilization of Hardwood Chips:

Steam sterilization is a common method used for sterilizing hardwood chips. You will need a pressure cooker and a steam generator for this method. Fill the pressure cooker with water and heat it until it produces steam. Place the hardwood chips in a plastic bag and seal it, making sure there is enough room for expansion. Insert the steam generator into the bag, seal the bag, and place it in the pressure cooker. Cook the chips for 2-3 hours at 100-120°C (212-248°F). After cooking, let the bag cool before using the hardwood chips as a substrate.

Inoculate the substrate:

Once the substrate is sterilized, mix it with your inoculated oyster mushroom spawn to inoculate it. This is a simple step. But, make sure that you do it in a clean space.

Incubate the substrate:

Place the inoculated substrate in a warm and dark location and wait for the mycelium to grow.

  • The incubation process involves allowing the mushroom mycelium to colonize the substrate fully. This process can take anywhere from 1 to 4 weeks, depending on the temperature and humidity levels in your growing area.
  •  During the incubation period, the mycelium will start to spread throughout the substrate, forming a dense white network. This is a sign that the mycelium is healthy and growing correctly. If you notice any green or black mold growing on the substrate or a foul odor, it's a sign of contamination, and you should discard the substrate to avoid ruining your crop.
  • To incubate the substrate, place it in a warm and dark location. The ideal temperature range for oyster mushroom mycelium growth is between 65°F and 80°F (18°C to 27°C), with a relative humidity of around 80%. You can use a heat mat or incubation chamber to maintain temperature and humidity levels consistently.
  • Pro tip: To speed up the incubation process, after mycelium has grown about 30%, you can break up the substrate into smaller pieces, creating more surface area for the mycelium to grow.


  • Once the mycelium has colonized the substrate, transfer it to a fruiting chamber and wait for the mushrooms to develop. Check out our Mushroom Fruiting Monotub/Chamber DIY Guide for more information on setting up a fruiting chamber.
  • After the incubation period, the mycelium has colonized the substrate, and it's time for the fruiting stage. This is the stage where the tiny pinheads that began to develop during the end of the incubation period grow into mature mushrooms. Here's what you can expect during the fruiting stage:
  • Timing: Fruiting can take anywhere from 1 to 2 weeks, depending on the environmental conditions and the variety of oyster mushrooms you're growing. Generally, oyster mushrooms fruit best at temperatures between 60°F to 70°F (15°C to 21°C), with a relative humidity of 85% to 95%.
  • Appearance: During the fruiting stage, you'll notice small, button-like formations called pinheads. These will gradually grow into mature mushrooms over a period of a few days. Oyster mushrooms grow in clusters, and you can expect to harvest several mushrooms at once.
  • Pro tips: To encourage optimal fruiting, here are a few pro tips:
    - Ensure proper ventilation: Oyster mushrooms require good air circulation to grow correctly. Make sure your fruiting chamber has proper ventilation to allow for the exchange of fresh air.
    - Maintain high humidity: Oyster mushrooms thrive in high humidity levels. Mist the fruiting chamber regularly to prevent the mushrooms from drying out.
    - Monitor temperature: Oyster mushrooms grow best at cooler temperatures. If the temperature is too high, the mushrooms may not grow correctly.
    - Harvest mushrooms when they're ready: Oyster mushrooms grow quickly and can reach maturity within a day or two. Check your mushrooms regularly and harvest them when they're fully grown but not yet releasing spores.
    Overall, the fruiting stage of oyster mushroom cultivation is an exciting time as you watch your mushrooms grow and mature. With the right environmental conditions and a little patience, you'll be rewarded with a bountiful harvest of delicious and nutritious oyster mushrooms.

By following these simple steps, you can grow your oyster mushrooms at home from inoculated spawn. Remember to avoid common mistakes, such as overwatering or under-ventilating your growing chamber. For more tips and tricks, check out our Mushroom Cultivation Beginner's Guide Blog Post. Happy growing!

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