someone help, contamination

RushWayne rushwayne at
Fri May 26 12:51:44 EST 2000

Jesse Canceo (cancej at wrote: 
<<Help!  I have only recently began experimenting with cultivating fungi after
taking a general mycology class at my university.  The problem is an
unidentified contamination; the following is a description.  About 4-5 days
after the first sign of mycelium penetration throughout the substrate,
growth suddenly halts.  The mycelium then becomes incredibly thick around
the unpenetrated substrate, as if it is trying to overtake the pathogen (it
is never successful).  There is no obvious growth of any contaminants and no
discolorations of any kind.  I know you should never smell infected
cultures, but I did.  You can smell it 10 ft. away from the closed jars.  I
have 3 other people tell me it smells like dirty socks.  The only spoilable
grain in the substrate is a wild brown rice.  I have tried 2 different
substrate sources, 2 methods of sterilization, and 2 different sources of
spore prints.  Can someone help identify this so that I can find the source
of the contamination.>>

The identification of the contaminant is usually not very relevant to solving
the contamination problem.  It is almost certainly bacterial, since there is no
visible growth in the area (the smell is also a giveaway). But if it were mold,
you'd still have the same problem.  You didn't mention your methods of
sterilization, or inoculation, or how you are keeping out airborne
contaminants, so any of those could be at fault. In general, this is the kind
of situation that the peroxide method was designed to solve.  
Visit my website at for information on growing
gourmet mushrooms without air filtration or autoclaves using hydrogen peroxide
to prevent contamination.

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