Growing Shimeji Mushrooms

Growing Shimeji Mushrooms at Home

Growing Shimeji mushrooms at home can be a rewarding and enjoyable experience, offering a delicious addition to your culinary repertoire. This guide will walk you through the process, from preparing your spawn to harvesting your first crop. Whether you’re using pre-sterilised grow bags or creating your own setup, we’ll cover all the essential steps and optimal conditions for success.

Shimeji mushrooms, known for their rich flavor and delicate texture, are popular in Asian cuisine. They come in two main varieties: the brown beech mushroom (Hypsizygus tessellatus) and the white beech mushroom (Hypsizygus marmoreus). Growing Shimeji mushrooms at home is possible by providing them with specific environmental conditions that replicate their natural environment.

Materials and Equipment

Basic Substrate Recipe:
50% hardwood sawdust
30% wheat bran
20% soybean hulls
Add water to achieve 60-65% moisture content

Alternative Substrate Recipe:
40% hardwood sawdust
40% rice bran
20% cornmeal
Add water to achieve 60-65% moisture content

Suitable Grains for Spawn

Rye, Wheat, Millet, Sorghum, Oats

Containers

Mushroom grow bags
Plastic bins with lids
Plastic (PP) mushroom bottles
Glass jars (wide-mouth)

Growing Shimeji

First – Prepare your Spawn

Sterilise the Grain

The first step in growing Shimeji mushrooms is to prepare or buy the sterilised grain you want to use as spawn. Rinse the grains thoroughly and then allow them to soak in clean water for 12-24 hours. Next, drain the grains to remove the water and then add them to boiling water and allow them to simmer for between 10-20 minutes depending on the grain used. Drain the grain again and spread it out on a flat surface to allow it to dry – you want the outer shells of the grain to be dry to touch but without drying out the inside of the grain. Next, put the grain into your chosen container (autoclavable bags, jars or similar containers) and sterilise them at 15 PSI (121°C) for 90 minutes. The alternative to this is to buy our sterilised rye grain packs.

Inoculate the Grain

Once the grains have been removed from the steriliser/autoclave/pressure cooker and have cooled to room temperature you can inoculate them with liquid culture. Keep the containers closed or sealed until you are ready to use them. In a sterile environment, inoculate the grains by injecting a clean liquid culture of Shimeji mushroom mycelium using a sterilised needle. Alternatively you can briefly open the container to add a slice of ready-colonised agar.
Ensure your containers are properly sealed and shake them to ensure you have distributed the mycelium evenly in the grain.

Incubation

Incubate your inoculated grain by storing it in a warm (22-25°C) dark place. You can shake the containers every few days to help ensure even colonization.
While it will vary according to environmental conditions and both the amount and quality of culture used to inoculate the grain, full colonisation typically takes 2-3 weeks.

Next – Prepare the Substrate

Choose and mix your substrate

When your grain is fully colonised, decide which substrate recipe you want to use and collect your supplies. Carefully weigh and combine the chosen substrate ingredients and mix them thoroughly. Once the dry ingredients are mixed, add the neccessary amount of water – you need to aim at a total moisture content of 60-65% (by weight) by adding water until the substrate feels moist but not soggy. When growing Shimeji mushrooms, as with other types, it is important that you sterilise your substrate to kill off any competing fungi, spores and bacteria.

Sterilisation

Load your hydrated substrate into grow bags or jars and sterilise it in an autoclave/steriliser/pressure cooker at 15 PSI for 90 minutes.

Pasteurisation

We would always recommend sterilisation but some growers prefer to pasteurise their substrate and they typically heat the substrate in a water bath at 65-75°C for 1-2 hours.

Inoculating the substrate with spawn

When you are certain your grain has been fully colonised, leave it for another couple of days, just to be sure.  Once ready, mix your substrate with the fully colonised grain spawn – around 1 part spawn to 5 parts substrate will work well. Distribute this mixture into grow bags, plastic bins, bottles or other suitable containers.

Incubation

Return your now inoculated grain and substrate mix to incubation, maintaining a steady temperature of 22-25°C in a dark place. You need to maintain high humidity (80-90%) during this stage and you can do this by covering containers with plastic lids or using humidity tents. Again, depending on environmental factors and the strength of your spawn, full colonisation typically takes 3-4 weeks.

Growing Shimeji – Fruiting

Initiate Fruiting Conditions

Once the substrate is fully colonised, move the containers to a fruiting chamber and reduce the temperature to 16-18°C. At this stage, you need to provide your grow with indirect light (500-1000 lux) for 12 hours a day (don’t place in direct sunlight), and you should increase humidity to 90-95% using a humidifier or misting. These changes imitate the conditions which cause the mushrooms to start fruiting in the wild.

Ensure proper air exchange to prevent CO2 buildup by using an air exchange system or manually fanning the containers 2-3 times a day, and mist the substrate surface daily to maintain high humidity but take great care not to over-wet, as this can create contamination and mould.

Harvesting Shimeji Mushrooms

Shimeji mushrooms are ready to harvest when the caps are fully opened but just before the edges start to curl. To pick them, gently twist and pull the mushrooms from the substrate. Doing it carefully you will be able to avoid damaging the mycelium. Once picked, harvested Shimeji mushrooms can be stored in a paper bag in the refrigerator for up to a week.

Troubleshooting Common Issues

Contamination: Ensure all equipment is thoroughly sterilised and maintain a clean working environment to prevent mold and bacterial contamination.
Slow Colonisation: Check temperature and moisture levels; adjust if necessary to promote faster growth.
Pinning Issues: Ensure proper light, humidity, and fresh air exchange to encourage pinning and fruiting.

This is a guide specifically for growing Shimeji mushrooms, but we have growing guides for other mushroom species here on our mushroom growing guides page.