Hi Karen,
You might find that this works a few of times, especially if the spawn is vigorous and well colonised before you expand it again, and if you use it at a high rate.
The times that I have done this I’ve found mixed results – sometimes it worked well but the majority of the time it resulted in some green mould in the new substrate. I think this happens because some mould spores are present (although not at all visible) in the substrate being used as ‘spawn’.
This is the problem with expanding a ‘spawn’ source likely to contain other organisms other than the Oyster mycelium. When you break it up and mix it into new substrate there’s a chance you also give other species (especially blue/green moulds) to prosper as well. This is why spawn is normally a pure mushroom culture growing on a steruile substrate – so you can be sure of what you are expanding.
That’s not to say it’s not worth trying though – I’ve definitely had a good number of successes like this and it can save a lot of money on buying new spawn. I think the key if you do it would be to use it at a very high ratio of 1:2 or 1:3 as you suggest.
Let us know how it goes!
best wishes, Adam 🙂
.
