GROWING GOURMET - Anto2ni.it

Figure 101. One memod for preparing grain spawn
is to simply pour dry grain into glass jars, add water,
allow to sit overnight, and then sterilize.
Advantages of this method are: one-step process;
less fuel consumption; and less handling. One disadvantage
is uneven water absorption.
filter disc. By allowing the grain to soakfor 12-
24 hours, the heat resistant endospores of
bacteria germinate and become sensitive to
heat sterilization. Before use, the filter discs
should be soaked in a weak (5%) bleach solution
to dislodge and disinfect any imbedded
contaminants.The next day, the jars are shaken
by striking them against a rubber tire, or similar
surface, to mix together the more moist and
drier grain kernels. Once shaken, they are
promptly placed into the sterilizer. The advantage
of this method is that it is a one-step
procedure. A case can be made that starches and
other nutrients are preserved with this method
since the water is not discarded. Proponents of
the first method argue that not only is their start-
GENERATING GRAIN SPAWN 129
ing material cleaner, but this second technique
causes the grains to have an uneven moisture
content. The reader must decide which is most
suitable. Neither method, in my opinion, merits
endorsement over the other.
With excess water, grain kernels explode, exposing
the nutrients within, and making them
more susceptible to contamination. Exploded
grain kernels also cause clumping and sites of
depressed gas exchange, environments wherein
bacteria proliferate. The shape of the intact
grain kernel, with its protective outer surface,
selectively favors the filamentous mushroom
mycelium and produces a spawn that separates
readily upon shaking.
Suitable Containers for Incubating
Grain Spawn:
16 fi. oz. mineral spring water bottles,
quart mason jars, liter bottles
½ gallon jars
1 gallon jars
2 ½ gallon jars
Polypropylene plastic bags
Formulas for Creating
Grain Spawn
Moisture content plays a critical role in the
successful colonization by mushroom mycehum
of sterilized grain. If the grain is too dry,
growth is retarded, with the mycelium forming
fine threads and growing slowly. Should too
much water be added to the grain, the grain
clumps, and dense, slow growth occurs. Higher
moisture contents also encourage bacterial
blooms. Without proper moisture content,
spawn production is hampered, even though all
other techniques may be perfect.
The optimum moisture for grain spawn falls
within 45-55%, with an ideal around 50%. To
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