"Pavel314" wrote...
We have one of those propane turkey cookers which my wife uses for dyeing
wool. I put some water in the bottom, put the composted manure in the
perforated container that sits within the main pot, covered it, and let it
cook and steam for a half hour, to kill any wild fungi that might have been
present.

I tried to grow mushrooms once and every source I read said that ordinary
boiling won't work, you must have the higher temperature a pressure cooker
produces to kill all bacteria and fungi that might compete with your
spores. Without proper sterilization you might get lucky a few times and
have the spores successfully colonize the medium, but more likely the
bacteria will take over and kill the spores. Other molds might also
colonize the medium and until fruiting you probably couldn't tell that
they weren't your species. Oh, but I do remember one source that said if
a pressure cooker wasn't available, that repeated conventional boiling
over a day or two might be sufficient (as long as the substrate is
contained in an airtight canning jar). After sterilization, the trick
is to innoculate the substrate with the spores or germinated mycelia
without introducing any bacteria into the jar, otherwise you wind up with
a jar of rotten grain.