grain spawn question

Joe Harrington joeharr at
Sat Nov 30 01:09:04 EST 1996


stewart at (Paul Stewart C/O ABIOGEN) wrote:
>I am attempting to grow oyster and shiitake spawn on grain in mason jars. The 
>oyster is growing on oats (all I could find right now), and I have no holes in 
>the tops of the jars. I am incubating them at about 20-24 centigrade (70-75 F) 
>and am wondering if I should periodically open them in the laminar flow hood 
>to allow air exchange. Each jar is about 1/2 full. Any suggestions?

By "oats" I assume you mean oat grain? Most kinds of grain would be 
fine, as long as it is sterilized befor inoculation. Spent coffee grains
would probably do quite well with oyster spawn.

The spawn does require some air exchange during the incubation period.
Filter disks that fit the inside of the mason jar lid are available.
You need to drill a 3/8" hole in the lid for air exchange. The filter
disk is microporous, good down to 3 microns. You could also use a piece
of open pore polyfoam, similiar  to the kind used in pillows and some
matresses. I use it quite often and never had a problem with 
contamination, plus is is economical, reusable, and autoclavable.

70-75F is a good temp for the spawn run. A good oyster strain should
fully colonize the jar in 8-14 days. Shake the jar periodically to 
avoid the grain clumping up.

Shiitake is MUCH slower growing than oyster, depending on the strain you
use. After you get a good run with the grain, start a new batch using 
sawdust for inoculation of your substrate.

>Also, a friend who is growing red wigglers for an organic farmer asked if 
>mycelium would survive passage through the gut of the worm. His idea is to 
>inoculate leaf litter with the selected mycelium (edibles or mycorrhizal soil 
>fungi, etc) then empty the worms guts by feeding on peat moss for a couple of 
>days, then introducing them to the inoculated leaf litter. The worms would 
>fill their gut with mycelium, and would inoculate the soil or whatever they 
>were subsequently placed on. Sounded wacky enough to ask the group about. \

My guess is that the mycelium would probably not survive the ordeal 
of the enzymes produced in the digestive tracts of the earthworms,
although they might thrive in the earthworm castings. You didn't 
specific what species of mushrooms he was hoping to use?  Leaf litter
is somewhat high in nitrogen and many myceliums would not survive the
heat that is generated.  He'd be much better inoculating some fresh 
wood chip or sawdust piles, and then perhaps try transplanting that
to the leaf piles.


>Thanks for any interest.
>Paul Stewart
>stewart at

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