1. Substrate preparation:

You buy oyster mushroom spawn, for example a bag of 1 kg. Just estimate how many liters that are. Let's assume it is about 2 liters. That means that you want to prepare 4 liters of substrate.
You take the peat straw and chop it down to smaller pieces (2-5 cm long). Then for 4 liters you add 1-2 cups of spent coffee ground or 1 table spoon of blood and bone meals. You mix it all really really well. Then you put it into an old pillow case and close it for now.

2. Substrate pasteurization

Now comes the pasteurization which kills the bad microorganisms but leaves the good one alive. We want to heat up the substrate to about 70 degrees Celsius for about 1 hour. If you put the substrate with the pillow case into an esky and cover it with boiling water, that will cool down the boiling water to the right temperature (because the inside of the esky and the substrate are cooler). Leave it there for an hour and then take it out. Hang the pillow case up over night so the excess moisture can drip out.

Right moisture is really important. Moisture content is perfect if you squeeze the substrate with your hand really tight and only a few drops come out. Normally the substrate has the right moisture content if you leave it hanging over night. If not, wait a bit longer / put it in the sun and mix it occasionally.

3. Mixing the substrate with the spawn

Now it's time to mix the substrate with the spawn. I have good success using plastic shopping bags. Break up the spawn and mix it with the substrate really really well. Put it into the shopping bag but don't press it too much. There needs to be a little airflow all the way to the inside so the mushroom can grow there as well. Close the shopping bag by making a knot and punch a few holes into the bag with a pencil. Maybe 15 holes randomly around the bag.

4. Colonization

Now it's time to wait. Put it into a shady place with abour 25 degree Celsius. Never ever into direct sunlight. It takes about 2-3 weeks and the bag should be fully colonized by now. Once the bag is fully colonized it's time to initiate fruiting. In order for the mushroom to produce fruits it needs a few triggers. Those triggers are:

- Full colonization of the substrate
- Drop in CO2 and increase of O2
- Moisture evaporation

5. Fruiting

If your substrate is fully colonized, it should be somewhat hard and stable now. Like a big block of mycelium. Cut up the shopping bag and place the colonized substrate on a plate. Now use a new and transparent shopping bag and put it loosly over the substrate. Cut 2 finger sized holes into the top of the bags to provide a bit of airflow. From now on you should remove the bag once per day and fan the substrate, for example with a piece of cardboard. Just briefly for 5 seconds is enough. Then spray the substrate with water until you see little droplets on it. Now put the bag back on. Do this once every day and you should see fruits appearing now. Once the fruits grow bigger you can take of the bag but you need to spray a bit more then. Maybe 2-3 times per day. If you harvested all the fruits and you don't see any new ones, put the substrate into a bucket with water overnight, so it can hydrate again. Then start again. You can do this maybe 4-5 times until the substrate is depleted.

Good luck :)