GROWING GOURMET - Anto2ni.it

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CULTIVATING GOURMET MUSHROOMS
consider that the starting pH of make-up water
affects the final outcome. Each cultivator must
compensate accordingly.
The Bleach Bath Method
Similar to the hydrated lime method, but
household bleach (5.25% sodium hypochlorite)
is used as a disinfectant. I recommend
adding 5-6 cups of household bleach to 50 gallons
of water. A basketful of chopped wheat
straw is immersed. The straw is kept submerged
for a minimum of 4 and no more than
12 hours. The bleach leachate is drained off.
The straw is immediately inoculated. Should
colonization not be complete within two
weeks, contaminants naturally occur. Cultivators
should be careful where the toxic leachate
is drained.
The Detergent Bath Method
This method simply utilizes biodegradable
detergents containing fatty oils to treat bulk substrates.
Coupled with surfactants which allow
thorough penetration, these detergents kill a majority
of the contaminants competitive to
mushroom mycelium. The substrate is submerged
into and washed with a detergent
solution.The environmentally benign waste water
is discarded, leaving the substrate ready for
inoculation. Recently, many environmentally
safe soaps have been developed, especially in
Europe. Cultivators are encouraged to experiment
to match the best detergents to their
substrate materials. Here again, the goal is to
create a process that is both simple and applicable
for small and large scale cultivators.
The Yeast Fermentation Method
The fourth alternative method for rendering
straw is biological. Straw can be biologically
treated using yeast cultures, specifically strains of
beer yeast, Saccharomyces cerevisiae. This
method, by itself, is not as effective as those previ-
ously described, but has achievedlimited success.
First a strain of beer yeast ispropagated in 50
gallons (200 liters) warm water to which malt
sugar has also been added. Recommended
rates vary. Usually a 1-5% sugar broth is concocted.
Fermentation proceeds for two to three
days undisturbed in a sealed drum at room temperature
(75° F., 24° C.). Another yeast culture
can be introduced for secondary, booster fermentation
that lasts for another 24 hours. After
this period of fermentation, chopped straw is
then forcibly submerged into the yeast broth
for no more than 48 hours. Not only do these
yeasts multiply, absorbing readily available nutrients,
which can then be consumed by the
mushroom mycelium, but metabolites such as
alcohol and anti-bacterial by-products are generated
in the process, killing competitors.
Upon draining, the straw is inoculated using
standard procedures.
Another method of submerged fermentation
uses the natural resident microflora from the
bulk substrate. After 3-4 days of room temperature
fermentation, a microbial soup of great
biological complexity evolves. The broth is
now discarded and the substrate is inoculated.
Although highly odoriferous for the first two
days, the offensive smell soon disappears and
is replaced by the sweet fragrance of actively
growing mycelium. I hesitate to recommend it
over the other procedures described here.
The outcome of any one of these methods
greatly depends on the cleanliness of the straw
being used, the water quality, the spawn rate,
and the aerobic state of the substrate during
colonization. These methods generally do not
result in the high consistency of success (>
95%) typical with heat pasteurization techniques.
However, with refinement, these
simple and cheap alternatives may prove practical
wherever steam is unavailable.
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