Mushroom Growing 4 You

Growing Mushrooms at Home

Get Instant Access

Contaminants localized to point of transfer

Contaminants appear equally over the surface of agar media


Culture contaminated

Scalpel contaminated Airborne contamination

Contaminated media Insufficient sterilization

Hands upstream of cultures during inoculation in airstream of laminar flow hood


Isolate new culture.

Flame sterilize scalpel longer.

Filter air & use good sterile technique.

Increase sterilization time.

Keep hands downstream of inoculation site.

Media evaporates, cracks, before colonization is complete


Grain spawn contaminates before opening, before inoculation

Humidity too low Culture in airstream

Bacteria endemic to grain

Contaminants enter during cool-down

Mycelium does not grow Too dry

Bacterial contamination

Increase lab rH to 50% or wrap petri dishes with tape or elastic film.

Place cultures outside of airstream.

Soak grain overnight to trigger endospores into germination, making them susceptible to heat sterilization.

Filter air during cool-down or open pressure vessel at 1 psi in clean room.

Over-sterilized. Cook 1-2 hours at 15 psi.

Reduce surface area or porosity of filter media.

Soak grain spawn overnight.

Boil grai.i in a cauldron before sterilization.


Mycelium grows but spottily/incompletely

Grain spawn difficult to break up

Grain spawn appears pure, but contahiinates with mold or bacteria after inoculation.

Jars crack, bags break

Over-sterilized Culture not receptive to media formula

Insufficient distribution of mycelium through grain

Insufficient inoculation rate Bacterial contamination

Over-incubation Excessive water Use different type of grain

Mycelium endemically contaminated-co-existing with other organism(s) Over-incubation

Reduce sterilization time. Alter media formula.

Shake jars with greater frequency.

Increase amount of mycelium placed into each grain jar.

Clean up strain,

Increase sterilization time of grain.

Use spawn sooner.

Reduce water in formula by 10-20%.

Use rye, wheat or millet Add gypsum. See page 130.

Return to stock cultures or clean strain.

Use spawn sooner. Normal for old spawn to eventually support other microorganisms

Soak filter discs in bleach solution in between spawn runs.

Install micron filters. Observe good sterile technique.

Underside of filter ladened with organic debris, providing a medium for contaminants to grow through. Contamination airborne or from lab personnel.

Radical fluctuation Reduce temperature &

in temperature and/or pressure pressure flux. Inadequate quality Acquire higher quality, heat tolerant jars & bags.





Mushrooms fail

Improper Initiation

Consult Chapter 21.

to form


Alter moisture, temperature,

light, CO,, etc.

Bad strain

Obtain younger strain of

known vitality & history.

Chlorinated or

Use activated charcoal water

contaminated water

filters to eliminate chemical


Mycelium produces

Poor Fruitbody

Consult Chapter 21.

aborted mushrooms

Development Strategy

Bad Strain

Obtain younger strain of

known vitality & history.

Mite Contamination

Discard, disinfect and begin


Nematode Contamination

Minimize contact with soils &

increase pasteurization time.

Insect damage from

Shut down growing room,

developing larvae

"bleach bomb" for 24 hours,

install bug lights and/or frog

population, & re-fill with new


Second and third


Increase aeration or

crops fail to produce

contarr mation in core of

decrease depth of substrate.

substantially or at all

substrate mass

Growing room

Better management.


Bad strain

Acquire better strain.

Insufficient spawning rate

Increase spawning rate.

Green & black molds


Increase pasteurization time.

appearing on straw


Prolonged exposure

Lower C02 levels-increase air

to elevated carbon


dioxide levels

Incubation at too high a temperature

SUPPLEMENTED SAWDUST CULTURE Mycelium fails to grow Bags inoculated too hot through within two weeks

Insufficient spawning rate

Inadequate mixing of spawn through sawdust

Mis-match of mycelium & wood type Sawdust too dry Sawdust over-sterilized

Mycelium grows & then stops. Often accompanied by foul odors, slimy fluids. Yellow, green, or black molds

Presence of contaminants-bacteria or molds

Inadequate sterilization Sterilization sufficient but contaminated during cool-down Grain or Sawdust spawn infected

Person inoculating introduced contaminants

Bags not separated to allow heat loss during incubation

Airborne contamination Excessive carbon dioxide levels during incubation (> 25%)


Lower incubation temperature.

Allow to cool before substrate is inoculated Increase spawning rate. Increase mixing and/or spawn rate.

Use woods native to mushroom.

Increase moisture. Reduce sterilization time.

Consult Chapter 10: The Six Vectors oftion Contamination.

Increase sterilization time Filter air during cool-down, check autoclave seals, drains, etc. Use pure spawn.

Adhere to good sterile technique.

Space bags 2 in. apart, maintain air temperature at 75° F. (24° C.). Use HEPA filters & good sterile technique.

Increase surface area, or transpiration rate of filter media.




Mycelium grows but fails to produce mushrooms

HARVEST STAGE Mushrooms form, but abort

One of the above.

Monokaryotic strain-absence of clamp connections

Bad strain Mis-match of strain with substrate formula

Virus/bacteria/parasitic fungi/nematodes

Inhibited by environmental toxins

Bad strain

Poor environmental conditions Competitors' molds (Mycogone, Verticillium.

Trichoderma) & bacteria.

Chemical contamination, from solvents, gases> chlorine etc.

Incubate the bacterially contaminated bags at 40-55° F. (4-13° C.) for 1 month. (4060% are often salvageable.).

Mate with compatible monokaryon—check for clamp connecl!ons.

Acquire new strain.

Re-devise substrate formula.

Regenerate spawn from clean stock cultures. Remove source of toxins.

Acquire new strain. Consult Chapter 21 for species. Consult Chapter 10: The Six Vectors of Contamination.

Imbalanced Growing room environment. C02 and rH too high. Consult Chapter 21 Species Growth Parameters. Mist mushrooms with water containing 1/2 teaspoon of elemental sulphur per gallon. Equivalent to 1 lb. sulphur per 100 gallons of water.

Remove toxins,




Mushrooms form but stems are long; caps underdeveloped

Massive numbers of mushrooms form; few develop

Mushrooms deformed

Mushrooms produced on first flush, fail to produce subsequent flushes

Inadequate light

Excessive C02 Poor strain


Lack of oxygen, inadequate light

Inadequate substrate nutrition

Dilute spawning rate

Competitor organisms (.Mycogone, Verticillium, bacteria, etc.)

Inadequate air circulation Excessive humidity or watering

Bad strain

Chemical contamination

Increase or adjust light to correct wavelength.

Increase air exchanges. Obtain better strain.

Shorten primordia formation period^

Adjust according to the species' growth parameters See Chapter 21. Reformulate.

Increase spawning rate.

Re-balance growing room, environment to favor mushrooms & disfavor competitors. Increase air circulation. Reduce humidity to prescribed levels. Surface water must evaporate from mushrooms several times per day. Acquire better strain. Remove toxins.

Inadequate substrate nutrition Reformulate.


Consult Chapter 10: The Six Vectors of Contamination.

Window of opportunity Re-initiate, missed





Mycelium "panned"

Disturb substrate: break apart

& re-pack, allow to recover,

and re-initiate.

Poor growing

Improve management.

room management

Bad Strain

Acquire new strain

Flies endemic to growing

Inadequate pasteurization

Extend pasteurization period.


Open doors, vents, etc.

Improve seals at doors &


Poor growing room

Wash down growing room 2-3


times per day. Place 1 cup

bleach in drain to kill flies,

once per day.

Slow cycling of crops

Increase crop rotation.

Inadequate clean-up

Remove debris, wash ceilings,

of growing rooms

walls, & floors using bleach

between "runs"


"Bleach bomb" for 24 hours.

Bug traps. See Figure 384.

Frogs. See Figure 385.


Mushrooms quick to spoil

Mushrooms too mature

Harvest when younger.

when harvested

Mushrooms too warm

Chill mushrooms before

before packaging

placing in marketing


Mushrooms too wet

Reduce humidity several

when harvested

hours before harvesting.

Mushrooms improperly

Mushrooms need to breathe.


Cellophane or anti-condensate

gas permeable wrapping films


Mushrooms stored beyond

Sell mushrooms sooner.

shelf life


o best understand the individual components making up a mushroom farm, a comparative description of the environments and activities occurring in each room is helpful. Some rooms can accommodate more than one activity, as long as schedules do not conflict. This list is especially useful for designers, architects and engineers who are employed to design a complete facility. Since I do not advocate the use of caustic chemicals, pesticides, and other toxins, these descriptions may not fully address the needs of farms which handle manure-based substrates and subscribe to toxic remedies.

Was this article helpful?

0 0
Building Your Own Greenhouse

Building Your Own Greenhouse

You Might Just End Up Spending More Time In Planning Your Greenhouse Than Your Home Don’t Blame Us If Your Wife Gets Mad. Don't Be A Conventional Greenhouse Dreamer! Come Out Of The Mould, Build Your Own And Let Your Greenhouse Give A Better Yield Than Any Other In Town! Discover How You Can Start Your Own Greenhouse With Healthier Plants… Anytime Of The Year!

Get My Free Ebook

Post a comment