How to Grow Lentinula boryana

• 1 lb dry rye berries or wheat berries (single batch)
• Water for soaking and simmering
• 1 large pot
• Colander
• 1 polypropylene filter-patch grain bag (0.2-micron filter) or wide-mouth quart jar with injection port
• Pressure cooker capable of 15 PSI
• Scale-up: 3 lbs grain → 3 bags | 5 lbs grain → 5 bags

Measure 1 lb dry grain into a pot. Cover with cold water and soak for 12–18 hours at room temperature (68–72°F). Drain, then add fresh water and simmer over medium heat for 15–20 minutes until each kernel is fully hydrated through the center but not burst open. Drain and spread the grain on a clean towel or paper towels and allow to surface-dry completely — kernels must feel dry to the touch with no surface moisture before loading. Over-wet grain clumps in the bag, compresses under pressure, and creates pockets that harbor bacteria; under-wet grain colonizes slowly and invites Trichoderma. Load the surface-dry grain into the filter-patch bag to roughly two-thirds capacity, then fold and seal the bag. Sterilize at 15 PSI for 90–120 minutes. Remove from heat and allow the bags to cool completely to room temperature — at least 4–6 hours, or overnight. Never inoculate warm grain; heat above 90°F will kill the liquid culture.

• Lentinula boryana liquid culture syringe (12 cc)
• Cooled, sterilized grain bag(s) from Step 1
• Isopropyl alcohol (70%) and paper towels
• Still-air box or laminar flow hood
• Latex or nitrile gloves
• 3–5 cc liquid culture per 1 lb grain bag

Work inside a still-air box or under a laminar flow hood. Wipe the syringe needle and injection port with 70% isopropyl alcohol. Inject 3–5 cc of Lentinula boryana liquid culture into each 1 lb grain bag through the self-healing injection port or filter patch. Distribute the liquid across several injection points if possible rather than in a single spot. Shake the bag gently after inoculation to distribute the liquid culture throughout the grain. Out-Grow sells Lentinula boryana liquid culture ready to inject.

• Inoculated grain bags from Step 2
• Dark or low-light space held at 64–70°F
• Thermometer

Place inoculated grain bags in a dark or low-light area at 64–70°F. Lentinula boryana strongly prefers the cooler end of this range — target 64–68°F when possible. Do not incubate above 72°F; the species lags significantly at warmer temperatures, leaving grain vulnerable to contamination. After 5–7 days, white mycelium will begin advancing from each inoculation point. Shake the bag once when colonization reaches approximately 30% to break up mycelial knots and distribute growth evenly, then leave undisturbed. Expect full grain colonization in 25–45 days, slower than standard shiitake spawn due to this species' preference for cooler conditions.

• 4 lbs hardwood sawdust pellets (oak or mixed hardwood; not softwood)
• 1 lb wheat bran
• 1–2 tbsp gypsum (optional buffer)
• Approximately 5½ cups water (adjust to reach 60–65% moisture)
• 1 large polypropylene mushroom grow bag with 0.2–0.5 micron filter patch
• Impulse sealer or zip ties
• Pressure cooker at 15 PSI
• Scale-up: 3 blocks → multiply all quantities by 3 | 5 blocks → multiply by 5

Break the hardwood pellets down with water first — pour 4 cups of the water over the pellets in a large container and allow them to absorb and crumble into sawdust, approximately 10–15 minutes. Add the wheat bran and gypsum and mix thoroughly. Add remaining water gradually and mix by hand. The substrate is at the correct moisture level when you squeeze a fistful firmly and only a few drops — not a stream — of water emerge. Load the mixed substrate into a filter-patch grow bag, leaving 4–6 inches of headspace. Fold and seal the bag. Sterilize at 15 PSI for 90–120 minutes. Remove from heat and allow to cool completely before inoculation — at least 8 hours or overnight. Never inoculate warm mushroom substrate.

Out-Grow also carries wood-based mushroom substrate bags ready to inoculate if you want to skip preparation and sterilization.

• Fully colonized grain bag from Step 3
• Cooled, sterilized sawdust substrate bag from Step 4
• Isopropyl alcohol (70%), gloves, still-air box or flow hood
• Spawn rate: approximately 10% grain spawn by wet substrate weight (roughly 1 lb colonized grain per 5 lb substrate block)

Work in a clean area with 70% isopropyl alcohol applied to gloves and all surfaces. Before opening the colonized grain bag, squeeze and knead the bag thoroughly until the grain mass breaks apart completely and all clumps are separated. Open both bags. Distribute the broken grain spawn evenly across the top surface of the sawdust substrate before mixing — no pockets of grain in one spot. Work the grain through the substrate by mixing from the bottom up until no visible clumps of grain remain isolated from the sawdust. Refold and reseal the grow bag using an impulse sealer. Label with the date.

• Inoculated sawdust block from Step 5
• Dark or low-light colonization space at 64–70°F
• Thermometer

Place the sealed block in a dark or low-light space at 64–70°F. Do not allow temperatures to exceed 72°F — Lentinula boryana mycelium stalls and loses competitive advantage over contaminants above this threshold. The bag remains closed throughout colonization; internal humidity approaches 100% and requires no additional moisture management. Leave the block undisturbed. White mycelium will advance from each grain kernel outward through the sawdust. Over time, the surface will tighten and begin to form a dense, slightly leathery skin typical of Lentinula species. Full block colonization takes approximately 30–60 days at optimal temperature — longer than many oyster varieties, so patience is required. Any green, black, or olive patches that appear are contamination, not mycelium; discard affected blocks immediately.

• Fully colonized block from Step 6
• Fruiting chamber or grow room capable of holding 55–65°F
• Humidity source to maintain 90–95% relative humidity (RH)
• Fresh air exchange (FAE): passive vents or small fan on a timer
• Diffuse light source: 8–12 hours per day at low intensity
• Spray bottle for misting

Open the grow bag or cut a 2–3 inch X-shaped slit across the top of the block to expose the colonized surface. Move the block to a fruiting space at 55–65°F with RH at 90–95%. The temperature drop from colonization conditions to fruiting conditions helps trigger pinning — a shift of at least 5–10°F downward is recommended. Provide diffuse light for 8–12 hours per day. Mist the exposed block surface two to three times daily to maintain surface moisture without soaking. Run fresh air exchange (FAE) — passive slots or a fan running 5–10 minutes per hour — to keep carbon dioxide (CO₂) levels low; high CO₂ produces elongated, deformed pins. Small brownish cap primordia (pins) with white margins will emerge from the block surface within 5–14 days of moving to fruiting conditions.

• Clean, sharp knife or scissors
• Clean surface or tray for harvested mushrooms

Monitor developing caps closely as they approach maturity. Harvest when cap margins are just beginning to flatten but before they turn fully upward. The gills should be tight and pale — do not wait for heavy spore drop, which darkens the gills and signals overmaturity. Cut each mushroom cleanly at the base of the stem using a sharp knife; do not pull or twist, as tearing damages the block's leathery surface and reduces the yield potential of subsequent flushes. Work through the cluster systematically and harvest all mature caps in one session. After harvest, remove any remaining stem stubs from the block surface to prevent decay.

• Harvested block from Step 8
• Clean bucket or large container (if dunking to rehydrate)
• Cold water

After the first harvest, allow the block to rest for 7–14 days. During the rest period, return the block to colonization temperature (64–70°F) and close or refold the bag loosely. To rehydrate the block before inducing a second flush, submerge it in cold water for 4–8 hours — this restores moisture lost during the first fruiting cycle. Remove from the water, allow surface moisture to drain briefly, then return to fruiting conditions as in Step 7. Repeat the same fruiting trigger: drop temperature, maintain 90–95% RH, and provide FAE and diffuse light. Subsequent flushes typically produce smaller yields than the first. A block is spent when it produces no new primordia after a full rest-and-rehydration cycle, or when it becomes noticeably light, brittle, and structurally fragile.

• Oak or mixed hardwood logs, 4–6 inches diameter, 3–4 feet length
• Logs cut within the past 4–6 weeks (not freshly harvested same day; not aged more than 6 weeks)

Source freshly cut hardwood logs — oak is the preferred species for Lentinula cultivation. Logs cut too recently will still have active antimicrobial compounds in the sapwood that inhibit inoculation; logs aged past 6 weeks may already carry competing molds. Allow freshly cut logs to rest in a shaded, well-ventilated location for 2–4 weeks if they were harvested the same day. Inspect each log — avoid any showing existing mold, excessive cracks, or insect damage. Do not use softwood logs; the resins and extractives in conifer wood inhibit Lentinula boryana mycelium.

• Prepared hardwood logs from Step 1
• Drill with 5/16-inch bit
• Lentinula boryana grain spawn (colonized per Method 1) or plug spawn
• Cheese wax or beeswax, wax applicator, heat source
• Inoculation rate: drill holes approximately 2 inches apart in rows 4–6 inches apart, staggered in a diamond pattern around the log circumference

Drill holes approximately 1 inch deep in a staggered diamond pattern around the log, spacing holes roughly 2 inches apart within each row and offsetting rows by 2–3 inches. Pack grain spawn or plug spawn firmly into each hole using a gloved finger or spawn tool — fill completely with no air pockets. Immediately seal each hole with molten cheese wax or beeswax applied with a dauber or brush. Wax sealing prevents the spawn from drying out and blocks competing organisms from entering the inoculation sites. Seal both cut ends of the log as well.

• Inoculated logs from Step 2
• Shaded outdoor or semi-shaded indoor space
• Natural rainfall or supplemental watering (do not allow logs to dry out completely)

Stack or lean inoculated logs in a shaded area protected from direct sun and drying wind. A "log yard" under tree canopy or a north-facing wall works well. Logs need to remain consistently moist without sitting in standing water. In dry climates or during dry periods, mist or soak logs periodically to maintain moisture — logs should feel heavy, not hollow and light. Colonization of hardwood logs takes considerably longer than sawdust blocks: expect 6–18 months before the log is ready to fruit, depending on ambient temperature and log density. Lentinula boryana's preference for cooler temperatures (targeting 64–70°F colonization range) means logs in hotter climates may colonize slowly or unevenly during summer months.

• Colonized log from Step 3
• Large trough or stock tank for soaking (optional but recommended for first fruiting)
• Cold water for soaking

To trigger fruiting, soak the colonized log in cold water for 12–24 hours — this cold shock and rehydration mimics the natural rainfall and temperature drop that triggers wild fruiting. Remove from the water and lean or stack in a shaded, humid outdoor area. In temperate climates, logs often fruit naturally in autumn and spring when temperatures drop into the 55–65°F range. Pins emerge from the bark surface and inoculation sites as small brownish primordia with pale margins. Harvest by cutting cleanly at the base of each stem when the cap margin is just beginning to flatten, before full upward curl and spore drop. After each flush, allow the log to rest in its shaded location for 6–8 weeks before the next soak-and-trigger cycle. Logs may produce for 2–4 years before becoming exhausted.