Finally the time has come, you have your grain spawn colonised and your bulk sub prepped and ready and its time to spawn to your monotub and wait for your mushrooms to fruit !

Items you will need:

  1. Pre made monotub with holes in correct places with some form of filters, either polyfil or micropore tape
  2. Colonised grain spawn
  3. Pasteurised Bulk Substrate
  4. Alcohol or bleach solution


You need to decide on the right size tub for the amount of spawn you have made. Spawn and bulk substrate should be mixed at a ratio if 1 parts spawn to 2/3 parts bulk substrate. If you have to much bulk substrate it could take to long to colonise and contamination could set in.

Say you have 1l of spawn and you mix it with 2l ob bulk you would have a total of 3l to spawn to your tub. This should fill the tub around 4-5cm high, an easy way is to pore 3l of water in your tub and see how far that comes up the sides and find the correct sized tub according to that.

Method to spawn to tub:

  1. Make sure you are clean, wash your arms wear a mask if you have
  2. Clean your tub well inside and out and the lid with alcohol or a bleach solution.
  3. Block the holes with micropore tape or polyfil
  4. Clean the containers your bulk sub and spawn are in
  5. Mix your bulk sub and spawn in the tub ( we like to keep about 10% of the bulk behind and sprinkle a layer of sub right at the top after you have mixed everything well.
  6. Put the lid on

You can leave the tub in a dark room and wait for colonisation to occur, this should happen within about 2 weeks. Once the entire tub is colonised you can move it into a lit room near a window but not near direct sunlight.

You should start to see pins growing after a few days. No need to open the tub up until this point.

As the mushrooms are growing you may need to open the tub and mist the sides a couple of times a day to keep the tub moist, creating a humid environment.