GROWING GOURMET - Anto2ni.it

142 GENERATING GRAIN SPAWN
interior. (See Figure 137.)
Once the bags are cooled, they are unfolded
by hand, being careful to only touch the outer
surfaces of the plastic. A jar of spawn is selected,
shaken and opened. Using a roll-of-the
wrist motion, spawn free-falls into each bag at
a recommended rate of 1:10 to 1 :40.The bag is
then laid down so as to open into the airstream.
The top 2 inches of the bag is positioned over
the element of a clean heat sealer and expanded
open, again by only touching the outer surfaces
of the plastic. The clean air coming from the
laminar flow filter inflates the bag. I gently
press on the sides which further inflates them
before sealing. The top arm of the sealer is
brought forcibly down, often times two or three
times in rapid succession, pausing briefly to
allow the plastic seam to re-solidify. Each bag
is squeezed to determine whether the seam is
complete and to detect leaks. (Often, pin-hole
leaks can be detected at this stage. Having a roll
of plastic packing tape, 3-4 inches wide, handily
solves this problem by simply taping over
the puncture site.)
If the bags hold their seal with no leaks, the
spawn should be mixed through by shaking
each bag. This cultivator strives to capture
enough air within each bag so that when they
are sealed, each bags appears inflated. Inflated
bags are much easier to shake and support better
mycelial growth than those without a
substantial air plenum. (See Figures 125—129.)
Spawn bags should be set on a shelf, spaced
1/2 inch or more from each other to counter-act
heat generation.After four days, each bag should
be carefully inspected, laid on a table surface, and
rotated to disperse the colonies of mycelium. In
another week, a second shake may be necessary
to ensure full and even colonization.
The advantages of using bags for processing
grain spawn are:
1. In the limited space of a sterilizer, more
grain can be treated using bags than jars.
2. Bags, if they break, are not dangerous. Being
cut by glass jars is one of the occupational
hazards of spawn producers.
3. Since the bags are pliable, spawn can be
more easily broken up into individual kernels
and distributed into the next substrate. The process
of spawning is simply easier.
Liquid Inoculation
Techniques
A rain storm is a form of liquid inoculation.
The earliest fungophile, unwittingly or not,
used liquid inoculation techniques. Every time
mushrooms are eaten, cooked or washed,
spores are disseminated in liquid form. Nature's
model can be modified for use within the laboratory.
Currently several strategies incorporate
liquid inoculation methods. The advantages of
liquid inoculation are the speed of colonization,
the purity of spawn, and the ease of handling.
Spore Mass Inoculation
The ultimate shortcut for culturing mushrooms
is via spore mass/liquid inoculation
directly into bulk substrates. Primarily used in
China, this technique works well with Oyster
and Shiitake mushrooms, but is also applicable
to all the mushroom species discussed in this
book. In effect this process parallels the technology
of the brewery industry in the cultivation
of yeasts, Saccharomyces cerevisiae and allies.
Large fermentation vessels are filled with sugar
broth, inoculated with pure spores and incubated
and aerated via air compressors.
Spore mass inoculation of sterilized substrates
is limited to those species which form
mushrooms under totally sterile conditions.
(Spores collected from wildly picked mushrooms
have too many contaminants.) Those
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