I just officially opened my personal little mushroom growing season. I have already (even successfully, occasionally 🙂 ) made grain spawn by just propagating mycelium plugs in pasteurized grain in the past, but while this is a cheap and simple way to use up “leftover mushroom seeds”, it’s also unfortunately very prone to contamination and failure. I decided to try a more professional approach this time and got myself some liquid mycelium in a syringe and this time aimed for a sterile procedure. 

Growing Jars:

I took three glass jars with about 400 ml capacity each. Their screw caps each received a hole for a self-healing injection port (12 mm dia., like these) and a ventilation hole (20 mm dia.), covered with a double layer of Micropore™ tape. A step drill bit works best for this task. Try to clean and smooth the edges and make sure both injection ports and sealing tape are autoclavable.


I had 650 ml of organic wheat left here that I soaked in ~1 l of boiling water in a bowl, covered. I strongly advise using full-grain organic wheat, since it will not be treated with any bactericides or funghicides. Let this sit for about 45 minutes, then drain in a sieve until moist but not wet anymore, about 30 mins. more. Divide the grains to the jars evenly and close them.


I remodeled my steaming insert for the pressure cooker (see a small how-to here) a little to elevate it from the pot base. Add 1.5 l of water and sterilize the jars for a full 60 minutes, then let them cool to room temperature, covered with a clean kitchen cloth.


With disinfected hands, assemble the spore syringe, leaving the cap on the needle until the very last moment. Disinfect the injection port thoroughly with alcohol, making sure not to spray on the micropore tape (it might weaken the tape’s filtering capabilities). Remove the cap, poke the needle in and inject a portion (I split it in three, of course) in a circular motion. Replace the cap and repeat for the remaining jars.

Now store the jars in a slightly cool and dark place and allow the mycelium to colonize the grain for about three weeks minimum.