Expanding Spawn

In New Zealand I find the spawn to be a bit pricy, in the order of $12 to $50 for 1L, when you can find it, which is about 700gm of it, or enough for 1.5 to 4 5kg bags depending how brave I’m feeling, with each bag able to yield about $25 to $30 based on a 15% yield so far, it’s just not economically viable.

So what I’ve been doing is expanding my own Spawn with the following steps.

• Sourcing my own Rye Grains
• Soaking overnight in a mix of Instant Coffee and cold water
• Boiling for about 10 mins to hydrate.
• Straining and cooling for about 30 mins
• Loading about 2 to 3kg of hydrated grain into filter patch bags (less than half full)
• Folding the bag over several times at the top to get out as much air as possible and then taping across to hold closed (not seal)
• Loading into a pressure cooker and cooking for about an hour or so depending how many bags, after the time is up I cover with a blanket and leave to cool over night.
• Then I use a glove box to put about 100gm to 200gm of spawn in each 2 to 3kg bag
• I incubate it just like the bags of coffee substrate at 25degC, it takes a max of 3 weeks to fully colonise the grain.

It’s about 3 hours work on a Sunday, but it reduces the per bag cost of spawn by a factor of 10, making the whole process commercially viable.

Depending on ones spawn supplier the above process might make them unhappy, if it ever does, i’ll either source liquid culture or just do the whole process myself.

I haven’t experienced senscience yet, but it is a threat especially if the spawn supplier is flogging 3rd or 4th generation spawn, so I would suggest having at least a months worth of spawn spare before you start making your own to allow time to see if the spawn will multiply happily.

• This topic was modified 9 years, 7 months ago by Charlie.