Natural
Log Shiitake Mushroom Production, Processing and Marketing
Shiitake,
comes from the Japanese
Shii, which means oak and take
which means mushroom, it is the second largest cultivated mushroom species in
the world, second only to the white button mushroom or champignon (Agaricus bisporus). This mushroom has been cultivated in China and
Japan for hundreds of years,
a major upswing in
production occurred in the late 1940's after the development of modern
cultivation techniques by the Japanese. The shiitake market in both fresh and
dried format has grown to be a world wide multi-billion dollar industry, the
bulk of which is still centered in the Orient with Japan and China being the
largest producers and consumers. Shiitake, and other mushrooms, are a much more
common staple in oriental households. The average consumer there is more aware
of the excellent nutritional and medicinal properties of mushrooms and they are
incorporated almost daily in their diets. North Americans on the other hand know
little about mushrooms, in many cases have a slight fear of them or often hold
the misconception that they have little or no nutritional value.
North America got a late start in shiitake mushroom cultivation mainly
because of a mistake by the US Department of Agriculture. For a long period the
USDA was under the mistaken belief that shiitake, or in Latin Lentinula
edodes, was
a fungus that attacked railway ties ......, so they banned importation of the
live cultures into the USA. In 1972 the mistake was realized and restrictions
were lifted, since then production in the USA and Canada has steadily risen,
shiitake are now fairly common on supermarket shelves of big cities and along
with increased good press on exotic mushrooms, consumption of this food item is
likely to steadily increase.
Production
Shiitake
is cultivated in two ways, outdoors on natural hardwood logs or in a climate
controlled building on artificial logs made of hardwood sawdust and various
nutrients. The advantage of outdoor production is minimal capital investment,
the logs can be cut from your own bush lot or purchased locally, and
since they are kept in the bush under a canopy of trees to fruit, there is no
need of a building. Another advantage is that in general a better quality
product is produced outdoors even though there is quality degradation if the
mushrooms are soaked by heavy rains and there may be some possible pest loss due
to slugs depending in your location. The disadvantage is seasonal production
only, versus year round indoor cultivation, and
a somewhat heavier work load especially if you have large diameter logs.
All
mushrooms are actually the "fruits" or reproductive forms of various
organisms classified as fungi, they are like the apples on a tree. The actual
fungus
is a white strand like mass called mycelium, if you see a mushroom in your
forest or lawn you will find the mycelium growing under the surface. Shiitake
mycelium is a primary wood decomposer, it degrades the lignin and other
components of wood and extracts the nutrients to feed itself. When it has
gathered enough resources the mycelium will try and reproduce itself by
producing mushrooms, which then release spores into the air. To cultivate this
mushroom, mycelium is introduced into the logs in the form of a cloned culture
called spawn.
The logs are then placed in an environment that is conducive to mycelial
growth and when the mycelium has taken over the logs (about a year in our
climate) we then stimulate them to fruit or wait for natural fruiting. By
keeping our logs in the right environment such as under a bush canopy, the
mycelium will continue to stay alive and degrade the wood until all the
nutrients are gone, periodically producing mushrooms during this process. The
average lifespan of an oak log is 1 year for every inch of diameter.
To
start with the logs must be freshly cut limb wood from a live tree, so there are
no competitor fungi in the wood. Winter cut logs are recommended because there
is a high concentration of sugars in the wood which will give the mycelium a
kick start. Oak is the best hardwood to use, its tenacious bark will stay on the
logs for years keeping the moisture inside and the competitors out. Reasonable
success however has been achieved by using species such as ironwood, alder and
birch but the longest and most fruitful production is achieved by using oak.
Once cut the limb wood can be left frozen in the bush until spring ,but it should
be cut into 4 ft. lengths and inoculated with the mycelium as soon
as the weather warms up. This is generally late April early May in
Ontario. If a heated greenhouse or building
is available inoculations can begin earlier. The logs should range
between 4" to 8" diameter, larger logs can be used but are very
unwieldy.
Introduction
of the mycelium into the logs is accomplished by drilling a series of evenly
spaced
holes into the logs. A small quantity of mushroom spawn is placed into
these holes and the holes are sealed. Spawn is available from various
manufacturers, it comes in two forms, sawdust spawn and plug spawn. Sawdust
spawn is mycelium growing through a sawdust mix, plug spawn is wooden dowels
with the mycelium growing on them. In general sawdust spawn is cheaper and works
faster than plug spawn, it is however more susceptible to drying out so the
holes must be sealed properly. Sawdust spawn is injected into the holes using
some form of inoculator, either manual or pneumatic, dowel plug spawn can be pushed in
with your fingers. A new type of sawdust spawn is sawdust plug spawn,
which is sawdust formed into small plugs and is pushed into the holes with your
finger. After the spawn is in, the holes are sealed with molten
cheese wax or in the case of pneumatic inoculators a small piece of Styrofoam is
placed in the hole by the machine. Sawdust plug spawn has a styrofoam backing
and is self-sealing.
The
logs are then stacked in the shade of the bush and are monitored for moisture
content, they should not be allowed to dry below 25% moisture content or the
mycelium will die. Watering the logs once a week (unless there is plenty of
rain) by setting up a sprinkler over the stacks is recommended for 3-4 months
after inoculation. The sprinklers should be on for 3-4 hours to thoroughly soak
the logs. Although this watering is not absolutely necessary, it has been shown
to speed up the process and often results in some mushroom in autumn if
inoculation is done in spring. The mycelium will colonize the whole log and by
the following spring/summer mushrooms will start to pop out from the sides of
the logs. At this time the logs are rearranged in the bush so that they are
standing up, this is accomplished by stringing wire between trees or posts and
leaning the logs alternatively on both sides. This allows the mushrooms to come
out without touching the ground and allows easy picking from each log.
Once
the mycelium has taken over the log completely, the trigger to produce mushrooms
is moisture, heavy rains will stimulate the logs to produce. Rather than wait
for rain however we can "force" the logs to produce by either soaking
them in cold water for about 12 hours or by setting up a sprinkler system on
them for 24- 48 hours. Soaking is the preferred method because the water has a
chance to get right into the center of the log. Depending on the ambient
temperature, mushrooms will start to form
in 1-2 weeks after watering and will be ready to pick in a few days after
that. In the cooler spring or late fall weather, the mushrooms grow slowly
producing a dense fleshed product, this is considered
the best quality. Summer growth is much faster producing a thinner
fleshed mushroom. Once the "flush" of mushrooms has been picked, the
logs are left to rest for six to eight weeks and then can be watered again for
another crop. Three to four flushes can be forced from April to December
depending on geographical location. Farmers with heated greenhouses can bring
the logs inside and produce during the winter as well.
The
average yearly production will be
1-2 lbs. per log
more if the logs are forced more often, however this will shorten the
lifespan of the log. The total average yield from one log will be in the neighborhood
of 8 lbs. with proper management techniques. Once all the nutrients in the log
are used up you may still be able to get some heat from the logs..
Harvesting
and Marketing
Shiitake
are sold fresh as well as dried.
Fresh
Fresh
mushrooms are picked when the veil over the gill breaks and should be
refrigerated as soon as they are picked, a
temperature of 3 degree C will give them a shelf life of up to three
weeks. The shelf life is considerably shortened if the mushrooms are soaking wet
and they
should be sold as soon as possible. Currently the grading for acceptable
quality fresh mushrooms
is
A and B grade; "A" being a good looking mushroom with the edges
of the cap still turned in, B grade is mushrooms with the edges splayed out, and
generally inferior to the top A grade. There is of course some percentage of the
crop that is not sellable, so you generally start eating more mushrooms than you
did before. This is not all bad as they are very good tasting (somewhat like
meat); they are an excellent source of protein, minerals and some vitamins.
Shiitake have polysaccharides in them that have anti- cancer effects and
stimulate the immune system, so not only will you eat more mushrooms but you
will eat them for longer. There is quite an interest developing in the
alternative health community for mushroom extracts due to their medicinal
effects, and this may lead to a possible use of the lower grades. The outdoor
method of cultivation is almost de-facto organic if you keep the logs away from
any sprayed fields. ORGANIC CERTIFICATION can help in the marketing considering
the current interest in chemical free products. Vegetable wholesalers, local
restaurants, farmers markets, supermarkets, gourmet and health food grocery
stores are all possible marketing venues for the fresh product.
The
competition to log grown shiitake comes from indoor sawdust block growers. The
quality of their product is generally much lower but they can offer it a lower
price. The public, and often wholesale buyers are unaware of how the mushrooms
are cultivated and the best quality they should look for. Often lowest price,
rather than quality is the criteria
used for purchasing. This has a negative effect on the whole industry
because the consumer, who is used to low costs for the white button mushrooms,
is now asked to pay quite a lot more for these exotic mushrooms. Unless he is
suitably impressed by the quality of the product, enough to warrant the extra
cost, it is unlikely that there will be a repeat purchase. Fresh mushrooms are
generally sold in 3 lb. Boxes. The current price
growers are getting from wholesalers is $ 5-6
per lb. for A, and $3-5 for B grade.
If
you plan to market your mushrooms into an established market such as Toronto and
are new at this you should consider marketing through another long established
grower. You may get a less for your product but it might save headaches in
trying to sell your mushrooms. Developing your own sales contact such as CSA
groups, farmer’s markets, your local supermarket etc. will increase your
profits. If you are selling directly to the above mentioned groups you should
charge either a wholesale price, which is generally up to 30% above farmer
price, or retail price if selling to the public.
Dried
Gluts
in the fresh shiitake market occur periodically but fortunately shiitake can be
easily dried, as a matter of fact world wide the bulk of shiitake is consumed
from reconstituted dried mushrooms. If the mushrooms are dried to about
twelve percent moisture content, sealed in plastic, they can keep practically
forever. Care should be taken that they do not get moist as they may mold. The
ratio of fresh to dry is approximately 7 to 1. At the moment the North American
market for dried shiitake is very competitive due to cheap imports from China,
the quality of these imports is very low but consumer ignorance of mushrooms in
general makes marketing a higher quality and priced product a struggle.
The same CSA groups, Farmer’s markets etc. should still be available
avenues for marketing. Alternatively, value added products such as homemade
soups, sauces etc. can be marketed.
Japan
is one of the largest producer of shiitake but it is also the largest consumer
and importer. The Japanese grading system for dried shiitake involves about a
dozen grades, the best grades are attractively packaged and used as gift items.
Japanese production
has declined in the last 10 years due to an ageing farming population not
being replaced by younger farmers and by declining oak log resources. Although
they have a program to
plant and harvest oak trees for shiitake logs,
with an average 15 year span between planting and logging , theirs
still is a declining resource.
Currently more and more Chinese and Korean imports are finding their way
into their markets. The Chinese imports are mostly cheap, low quality grades,
used for processing. The Korean products are of better quality but are more
expensive. My opinion is that we would have success marketing our better grades
to the Japanese market,
buyers have already shown interest in our production and they are looking
for container loads of dried shiitake. Unfortunately our
current
production is not sufficient to fill these orders on a consistent basis.
We are currently trying to co-ordinate a sales effort to smaller wholesalers and
to retailers who are willing to start with smaller orders. I believe that
outdoor log production, which makes use of a resource which is currently either
left in the bush or used as firewood after tree logging, could give farmers and
woodlot owners an added income from their bush, while promoting the
reforestation of land as the demand for oak logs increases.
For More Information Contact:
Mycosource Inc.
R.R. 1, Goodwood ON, Canada L0C 1A0
Tel: 416-402-9755
FAX: 416-963-5520
Internet: office@mycosource.com
