Oyster Mushrooms

Propagating Liquid Culture Instructions

Liquid Culture Preparation Steps:

1. Drill 2 holes

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• Silicone 5/16” hole with RTV silicone. Make a pea-sized blob on both sides of the hole with a smooth, ¾” wide taper to ensure proper adhesion. Allow to cure for 24 hours. (see BOM)

5/16”

hole

wide mason jar lid

3/16”

hole

3. Plug up smaller hole with Polyfil (see BOM) by tightly twisting the material into a sharp point then poking it though the hole until it will not pull through any further (it should be very snug).

BOM:

• Quart Jar
• Wide Mouth Canning Jar Lid
• RTV (High Temp.) silicone
• Polyfil
• Pressure cooker
• Dextrose + Light Malt �Exract.
• Inoculant syringe
• Cotton swab
• 70% Isopropyl Alcohol
• Spray bottle

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4. Mix 1 Tbsp. Dextrose + 1 Tbsp. Light Malt Extract with 500 mL water in a quart jar. �Screw on lid and cover lid with aluminum foil.

5. Pressure cook for 20 minutes at 15 PSI

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Culture Inoculation & Maintenance

1. Once the sugar water has cooled, remove it from the pressure cooker. Remove the foil, wipe the silicone with an alcohol wipe or cotton ball sprayed with alcohol, then spray the silicone with alcohol.
2. Remove the syringe needle cover, spray the needle with alcohol 1-2 times, then burn off the alcohol with a torch lighter until the needle is well-heated, but not red hot.
3. Allow the needle to cool for 30 seconds, then insert the needle into the silicone and squirt 1-3mL of culture into the jar.
4. Each day, steadily swirl the jar for 30-60 seconds, creating a strong vortex in the water so as to disssolve oxygen into it, allowing the fungus to breathe.
5. Once ⅔ of the liquid has been filled with a “cloud” of fungal tissue (mycelium), it is ready to use on sterilized grains.

Grain Spawn - Preparation

1. Rinse millet grains in water, washing off any dust or dirt, then soak the millet in non-chlorinated water for 3-4 hours until it is crunchy, but not hard in its center.
2. Drain off the water from the grains. Fill several quart jars half-full with the grains and screw down a lid like those made in the first slide. Cover the lid with aluminum foil. Pressure cook the jars for 60 min. at 15 PSI.
3. Collect the liquid culture jar. Wipe the silicone ports on all jars with alcohol, then spray them with alcohol.
4. Take a clean syringe and needle (i.e. unpackaged, or wrapped in foil and cooked at 15 PSI for 20 minutes with the liquid media jars) and suck up 5-15 mL of LC for each quart jar.Insert the needle into the grain jar and spray the LC across the grains. Place the grain jarss in a 60-80ºF space.
5. Once mycelium has covered 25-35% of the grains (~1 wk.), shake the jar for 10 seconds to mix the grains.
6. Once the grains have been covered with mycelium (~1 more wk.) they are ready to use. Do not let the mycelium overgrow and turn into a solid mass that is hard to break apart by shaking.
7. Alternately, simply order grains spawn (e.g. Winter Tree oyster (4 lb) such as the wide-termperature tolerant PoHu strain from Field and Forest).

Straw Preparation

1. Gather organic straw (not hay), shred it with a mulch shredder, lawn mower, or weed wacker, then pack it into burlap sacks.

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• Clean the straw by either soaking the sacks in 12-14 pH water (adjusted with low-magnesium / high-calcium hydrated lime) for 12-16 hours, or by soaking it in non-chlorinated water for 7-14 days until it smells somewhat foul.

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• Lift the sacks out of the water and allow to drain unti the straw stops dripping.

Straw Inoculation

1. Drill out a 5-gallon bucket with 15 equally-spaced ¾” holes around its perimeter and 4 ⅛” drainage holes in its bottom.
2. Clean the bucket with soap and water, then spray it down with alcohol and wipe dry with a clean paper towel. Wash your hands with soap and water, then spray them with alcohol.
3. Sprinkle 2 handfuls of the treated and drained straw down into the bucket, then sprinkle 20-30 kermals of the grain spawn across the straw.
4. Repeat step 3 until the bucket is ⅓ full. Using your hands or the bottom of another clean bucket, push the inoculated straw down firmly, packing it tight.
5. Repeat step 4 until the bucket is full.Place the bucket in a 60-75ºF, 60-70% relative humidity space to incubate. 2-4 weeks later, mushrooms will start forming out of the holes.

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