Manual: Chestnut Mushroom Spawn

Use the spawn as soon as possible after you receive it, or keep it in the fridge for a few weeks at most.

What you need:

• Chestnut mushroom spawn (70 grams)
• Sterile substrate (for example a mixture of hardwood sawdust and soy hulls)
• Pressure cooker or another heating method for sterilisation
• Clean working area

Preparing the substrate:

Prepare a suitable sterile substrate, such as a mixture of hardwood sawdust and wheat bran. Sterilise the substrate in a pressure cooker for 2 hours, or heat the substrate for a longer time at a lower temperature to achieve sterilisation.

Inoculation:
Add the chestnut mushroom spawn to the sterilised substrate in a clean working area. Mix the spawn evenly through the substrate. Use a ratio of roughly 1:10 spawn to substrate, so 70 grams of spawn is enough for about 700 grams of substrate.

Incubation:
Put the inoculated substrate in a dark room with a temperature between 12°C and 19°C. Let the mycelium grow and colonise the substrate completely. This can take a few weeks.

Growth and fruiting body formation:
Provide the right conditions for the growth and fruiting body formation of the chestnut mushrooms. Keep the temperature between 12°C and 19°C. To keep the humidity high, you can cover the substrate with a plastic bag with holes for ventilation. Put the bag on a wet cloth to raise the humidity around the substrate. Spray the inside of the bag with water regularly to maintain a high humidity, especially during the formation of primordia.

Harvesting:
Harvest the chestnut mushrooms when they are fully grown and before the edges of the caps start to curl up. Pull the mushrooms off the substrate. Some substrate will come along, but that way as few mushroom remnants as possible are left behind on the substrate.

Storing:
Keep the harvested chestnut mushrooms in a paper bag in the fridge. They stay fresh for about a week.

Enjoying:
Chestnut mushrooms are delicious and versatile in the kitchen. Try them in soups, sauces, stir-fries or as a side dish.

Second harvest:
After the first harvest it is possible to get a second harvest. Keep the conditions such as temperature and humidity the same as during the fruiting body formation of the first harvest. Over time new primordia will form again, and eventually new chestnut mushrooms will grow that are ready to harvest.

Clearing up:
When you are done growing chestnut mushrooms, remove the substrate from the growing bag or container. The substrate can be composted or used as a soil improver in the garden.
This manual should get you on your way to successfully growing chestnut mushrooms with the help of the spawn. Good luck and enjoy your home-grown mushrooms!