How to Grow Black Reishi (Ganoderma sinense)

• 1 lb dry grain (hard red winter wheat, rye berries, or millet)
• Water for soaking
• Large pot for simmering
• 1 medium filter patch grow bag (0.2-micron)
• Pressure cooker capable of 15 PSI

Scale-up: 3 lbs grain → 3 bags | 5 lbs grain → 5 bags

Rinse the grain and soak it in cool water for 12–18 hours at room temperature. Drain, then simmer the soaked grain in a large pot for 10–20 minutes until kernels are fully hydrated but not burst. Spread the grain on screens or towels and allow it to surface dry until kernels feel dry to the touch with no visible moisture on the outside — moist inside, dry outside. Load the surface-dried grain into a filter patch grow bag, fold and seal the top with a heat sealer or zip ties, then sterilize at 15 PSI for 90–120 minutes. Allow the bag to cool completely to room temperature before inoculating — hot grain kills liquid culture.

Out-Grow also carries sterilized grain bags ready to inoculate if you want to skip this step: Sterilized Grain Spawn Mushroom Bags.

• Ganoderma sinense liquid culture syringe — Out-Grow Ganoderma sinense Liquid Culture
• Cooled, sterilized grain bag from Step 1
• 70% isopropyl alcohol and still air box or flow hood
• Alcohol lamp or lighter for needle flame-sterilization

Inside a still air box or flow hood, wipe down all surfaces with 70% isopropyl alcohol. Flame-sterilize the needle, allow it to cool for a few seconds, then inject 3–5 cc of black reishi mushroom (Ganoderma sinense) liquid culture through the filter patch or self-healing injection port of the grain bag. Massage the bag briefly to distribute the inoculation point. Label the bag with the date.

• Inoculated grain bag from Step 2
• Dark or low-light space holding 77–86°F

Place the inoculated grain bag in a dark or dim location holding 77–86°F. Black reishi mushroom (Ganoderma sinense) mycelium is bright white and slightly cottony; it may become faintly cream-colored where metabolites concentrate. Do not open the bag during colonization. Shake the bag gently once the mycelium has grown 20–30% through the grain to distribute colonization evenly, then leave undisturbed.

At optimal temperature, the grain should show visible white mycelial growth within 5–10 days and reach full colonization in approximately 20–30 days. The bag is fully colonized when the entire interior appears uniformly white with no visible uncolonized grain visible at corners or the base.

• 4 lbs hardwood sawdust (from fuel pellets or raw hardwood chips — oak, maple, or mixed hardwood)
• ¾ lb wheat bran
• 1 tbsp gypsum (optional)
• Approximately 5½ cups water
• Large mixing container
• 1 medium or large filter patch grow bag
• Pressure cooker at 15 PSI

Scale-up: 3 blocks = 12 lbs sawdust + 2¼ lbs wheat bran + 16½ cups water | 5 blocks = 20 lbs sawdust + 3¾ lbs wheat bran + 27½ cups water

If using hardwood fuel pellets, add water gradually and allow them to absorb and break down into fine sawdust before mixing in the wheat bran and gypsum. Add water gradually until the substrate reaches field capacity — when squeezed firmly in the hand, 1–2 drops release but the substrate does not drip freely or crumble dry. Load the substrate into a filter patch grow bag and seal. Sterilize at 15 PSI for 90–120 minutes and allow to cool completely before inoculating.

Out-Grow carries ready-to-inoculate hardwood substrate bags to skip this step: Wood-Based Inoculate and Wait Mushroom Substrate.

• Fully colonized grain bag from Step 3
• Cooled, sterilized substrate bag from Step 4
• Still air box or flow hood
• 70% isopropyl alcohol

Spawn rate: 1 lb colonized grain inoculates up to 5 lbs of substrate (roughly 5–10% spawn by wet weight)

In a still air box or flow hood, wipe all surfaces with 70% isopropyl alcohol. Break down the colonized grain bag fully before opening — squeeze and knead the outside of the bag until all grain kernels separate completely. Open both bags and pour the loose grain spawn over the surface of the substrate, distributing it evenly across the entire top before mixing. Mix thoroughly until no visible clumps of grain remain isolated from the hardwood sawdust mushroom substrate. Fold and seal the inoculated substrate bag. Never inoculate warm substrate — it will kill the black reishi mushroom (Ganoderma sinense) mycelium.

• Inoculated substrate bag from Step 5
• Dark or dim space holding 77–86°F
• 60–70% ambient relative humidity (normal room conditions are sufficient — substrate is sealed in bag)

Place the inoculated substrate bag in a dark or low-light area holding 77–86°F. Do not open the bag. The sealed filter patch provides gas exchange without requiring an open environment. Black reishi mushroom (Ganoderma sinense) mycelium is white and will spread slowly but steadily from inoculation points outward through the hardwood mushroom substrate.

Allow 20–30 days for full colonization. The block is ready to fruit when the entire bag appears uniformly white with no remaining brown substrate visible anywhere in the bag, including at the base and corners.

• Fully colonized block from Step 6
• Fruiting chamber holding 72–77°F
• Humidifier or misting setup to maintain 85–95% relative humidity
• Diffuse indirect light source — 8–12 hours per day
• Fresh air exchange — at least 3 complete air exchanges per day
• Scissors or sharp knife to open the bag

Move the colonized block into a fruiting chamber holding 72–77°F. Cut or tear away the top of the bag to expose the top surface of the block. You may also cut slits in the sides if you prefer wall-pinning. Maintain relative humidity at 85–95% throughout fruiting — use an ultrasonic humidifier or mist the chamber walls (not the block surface directly) to keep humidity stable without waterlogging the surface. Provide at least 3 complete fresh air exchanges per day — fresh air exchange (FAE) is critical for black reishi mushroom (Ganoderma sinense) to develop full conk caps rather than antler forms. Provide diffuse indirect light for 8–12 hours per day. Temperature does not need a dramatic drop from colonization; holding the fruiting chamber between 72–77°F is sufficient to initiate pinning without cold shocking the block below 60°F.

First pinheads — small white-to-cream nodules emerging from the surface — appear within 7–21 days after fruiting conditions are applied.

• Pinning block from Step 7 in fruiting chamber
• Humidity maintained at 85–95% RH
• Continued FAE — at least 3 exchanges per day
• Diffuse indirect light — 8–12 hours per day

Once pins form, maintain the same 72–77°F temperature, 85–95% relative humidity, and strong fresh air exchange without interruption. Black reishi mushroom (Ganoderma sinense) conks develop slowly — from visible pins to harvestable conks takes approximately 20–30 days under consistent conditions. Do not allow the chamber to seal airtight at any point during this stage; elevated CO₂ from a closed chamber will produce antler-shaped growth rather than full conks.

Watch for the pore surface on the underside of each developing conk to form fully and the margin color to shift from pale cream or white to a consistent darker shade across the entire rim. Diameter growth will visibly slow over several days when the conk is approaching maturity.

• Mature conks from Step 8
• Clean scissors or a sharp knife (sterilized with 70% isopropyl alcohol)

Harvest each black reishi mushroom (Ganoderma sinense) conk when the pore surface on the underside is fully formed, the cap margin shows consistent color across its full circumference, and size increase has stopped. Twist and lift the conk at its stem base — grip firmly at the base and rotate with light upward pressure. For conks growing from cut slit sides, use clean scissors to cut the stem, leaving approximately 1 inch of stem attached to the block to preserve the regeneration site and reduce risk of rot from torn tissue.

Avoid pressing or handling the cap surface during harvest, as surface contact can damage the pore layer. Over-mature Ganoderma sinense conks will show heavy brown spore dusting across the pore surface, very dark and brittle cap edges, and extremely woody flesh with no active size increase — harvest before these signs appear.

• Spent block with short stem stubs after first harvest
• Clean water for rehydration (optional)
• Continued fruiting chamber at 72–77°F, 85–95% RH

After the first harvest, wipe any surface debris from the block and leave it in the fruiting chamber under the same temperature, humidity, and fresh air exchange conditions. Black reishi mushroom (Ganoderma sinense) blocks can produce additional harvests from the same block — industry data for Ganoderma species generally suggests 2–3 harvests per block, though species-specific flush counts for Ganoderma sinense have not been formally quantified in published research. If the block surface shows signs of drying, rehydrate by submerging in clean water for 1–4 hours, then return it to fruiting conditions. A block that has turned fully brown throughout, shows no mycelial activity after 30 days in fruiting conditions, or develops persistent contamination should be retired to outdoor composting or disposal.

Follow Steps 1–6 of Method 1 exactly — grain preparation, sterilization, inoculation, colonization, and substrate block preparation are identical. The bag-then-bed method diverges only after the substrate block is fully colonized.

• Fully colonized block from Steps 1–6
• Prepared shaded bed with drainage
• Fine moist soil — approximately 1 inch for covering each block

Remove the plastic bag from the colonized block entirely. Place each block upright in the prepared shaded bed, spaced at least 8 inches apart. Cover the sides and top of each block with approximately 1 inch of fine, moist soil — enough to hold moisture against the block without burying the intended fruiting surface. Build a shade structure or hang shade cloth above the bed to protect from direct sunlight. Install drainage ditches alongside the beds to prevent standing water pooling around the blocks.

Water the bed and surrounding soil regularly to maintain a consistently moist but not saturated state. During dry weather, mist the bed area twice daily. Relative humidity around the developing conks should remain at 85% or above — in very dry climates, enclose the bed partially with plastic sheeting while ensuring at least 3 fresh air exchanges per day inside the enclosure.

Once pins form, follow the same development and harvest criteria as Method 1, Steps 8–10. Harvest conditions (margin color, pore surface development, diameter growth cessation) and harvest technique (twist-and-lift or scissors for conks on the sides) are identical. After harvest, leave the blocks in the bed and continue moisture maintenance for subsequent fruiting cycles.