Drain and Cool
Once proper pasteurization is complete, drain your straw and allow it to fully cool. Rapid cooling can be obtained by spreading the straw out on a smooth clean table.
Try to maintain cleanliness here by washing the surface thoroughly and by disinfecting hands with alcohol or washing well and often.
Pay close attention to where contaminants could come from.
Step 3: Inoculate the logs
In this step, you add your grain spawn to the straw.
Using a higher spawn:straw ratio will increase colonization times and will increase your chances of success. I like to use 3lbs of spawn for each 20lbs of wet straw, or a ratio of about 15%. Using less than 10% greatly increases the chances of contamination.
Mix your spawn
Using a large tote, or table, mix your straw and spawn well. Try to get an even and thorough distribution. Also, make sure there are no pockets of packed straw that are still too hot from pasteurization. Again, make sure hands are disinfected or use nitrile gloves.
Stuff mixture into bags or container
You now need to stuff the mixture into a suitable container. Many things will work, including laundry baskets, 5 gallon buckets with holes drilled in the side, plastic bags etc.
I find the best option for a container is to use poly tubing – it’s versatile, you can watch colonization, easily spot contaminants and make the log any length you want. Also, the shape of the tubing allows for lots of surface area for fruiting, you can slice as many holes as you want and even cut holes if you notice unwanted pinning under the plastic.
Using poly tubing with a 16″ lay flat diameter will give you a log about 10.5 inches thick, which is a perfect size. Going too much bigger will cause an anaerobic core, eventually causing the log to contaminate.
Tie one end of the tubing with wire or a zip tie and stuff the mixture in one handful at a time. Press down as you go and pack the straw as tight as you possibly can.
This will prevent air pockets from forming between the straw and the tubing -thus preventing the mushrooms from pinning under the plastic. Once the log is the desired length, force all the air out of the log by pressing down hard and twisting the top of the tubing.
Tie off the top again with wire or a zip tie.
Punch holes for fruiting
You will need to punch holes into the side of the log for two reasons. First, your mushroom log needs to breathe in order for colonization to occur.
If no holes are punched, contamination is imminent. Further, your mushrooms will eventually fruit through these holes. It is similar to how they grow in nature.
The plastic acts like the bark on a tree protecting the mushrooms, while the holes act like cracks in the bark where the organism senses fresh air and an opportunity to fruit and eventually spread spores.
Use a blade to cut small x’s about 5 inches apart all around the entire bag. You can also use an arrowhead for faster hole punching. Make sure the blade or arrowhead is sanitized first with alcohol so that you are not introducing contaminants into the log.
If you plan on hanging the log, also poke a few holes in the bottom of the log so that excess moisture can drip out.
16″ Poly tubing is great for making straw logs.
