Shiitake mushrooms

A farm that buys prepared shiitake blocks has different equipment and skills from a farm manufacturing supplemented wood-based blocks. List what the supplier completes and what you must complete. Ask for strain identity, inoculation date, developmental stage, transport conditions and a written handover protocol. The phrase ready block is too vague for a production schedule.

For in-house manufacture, review substrate sourcing, formulation, treatment equipment, clean inoculation and incubation as a whole process with a qualified trainer. Material suitability includes its identity and contamination history; unknown treated wood is not a mushroom substrate. Begin with a controlled pilot and traceable inputs before buying equipment around an assumed output.

Shiitake block systems include development beyond initial colonisation, including a maturation and browning sequence. Learn the appearance and handling criteria for your strain and block process. A block that looks colonised is not automatically ready for the next fruiting intervention. Readiness depends on its developmental history as well as appearance.

Record bag opening, browning progress and any treatment dates for each lot. Compare representative blocks across shelves and note damaged packaging or abnormal patches. Where a supplier's instructions and a general guide differ, identify whether they refer to the same strain, substrate and production stage before deciding which method applies.

Fruiting induction, block handling and any soaking or temperature treatment must follow the validated block and strain protocol. Do not apply an arbitrary cold-water duration from a different production system. Record the treatment actually used, the block condition before and after it, and the subsequent pinning response.

Manage fruiting air, moisture and light with observations at crop level. After harvest, follow the programme for block recovery and later flushes rather than assuming the next treatment can begin immediately. Keep later-flush output and losses separate from the first flush so that total block performance is visible.

Compare two lots using saleable kilograms per received block and the number of days each lot occupied the growing system. A higher total yield with much longer occupancy may not create higher annual output. Use actual lot records to decide, not a single harvest photograph.

Logs also need something the plains rarely have: legal hardwood of the right age, shade, and water through a long wait. Blocks need an autoclave, a clean inoculation space and steady power. Pick the constraint you can actually meet.

Shiitake is where ICAR-DMR disagrees with itself, and a grower should see it rather than be protected from it.

Yield: the shiitake folder reports 35 to 45 percent of the wet weight of the substrate. The 2011 manual, same method, reports 15 to 30 percent. That is a factor of two.

Incubation: the folder gives 60 to 80 days at 22 to 26 C; the manual's table gives 50 to 120 days at 20 to 30 C. Fruiting temperature has three published values: 12 to 25 C, 12 to 18 C and 15 to 20 C.

So publish a range, name the document, and measure your own house.

The log system is cheap in cash and expensive in time. You buy logs and spawn, then wait through a spawn run measured in seasons, with shade, watering and theft to manage. It suits hill farms with their own trees and patience.

The block system is the opposite. It needs an autoclave, heat resistant polypropylene bags, clean hands and reliable electricity, and it repays that with a defined 60 to 80 day incubation and repeated flushes on demand.

One rule holds for both. Never carry a block number into a log yard or a log number into a block room. They are different crops that happen to share a name.

ICAR-DMR says shiitake will grow on almost any size and age of log, then gives the working specification: 9 to 18 cm diameter, from trees 15 to 20 years old. The species named are broad leaved hardwoods, including oak, Castanopsis, Elaeocarpus, Lithocarpus, birch and Carpinus.

Age matters because a young tree has thin sapwood and an old one is often already rotting. Diameter matters because a thin log dries out and a thick one takes longer to colonise.

Use sound wood with the bark intact. Bark is the log's skin; where it is knocked off, other fungi enter first.

Logs take sawdust spawn, not grain spawn. DMR publishes three sawdust spawn formulations built on sawdust with wheat or rice bran, sugar and calcium carbonate.

The process is a laboratory one. Containers are autoclaved at 20 psi for two hours, then inoculated and incubated for 30 days at 24 plus or minus 2 C. Unless you have that equipment and training, buy spawn from a recognised laboratory and check the date on it.

Spawn is placed into drilled holes and the hole is sealed, commonly with wax, so the spawn does not dry out and rain does not run in.

Signs to watch are the ends going white, the bark loosening slightly, and the log sounding duller when tapped. Photograph the stack monthly with a date.

Then rest the logs. The published rest stage is 7 to 21 days at 22 to 26 C with no light and 65 to 70 percent humidity. A dry period after harvest helps prevent contamination before the next induction.

DMR's folder formula is sawdust 80 kg, wheat bran 19 kg and calcium carbonate 1 kg per 100 kg of mix. The 2011 manual notes that the institute commonly uses a second formula with sawdust 80 kg, wheat bran 20 kg, cane sugar, calcium carbonate, citric acid and calcium sulphate.

Use broad leaved sawdust. DMR names tuni, mango, safeda or eucalyptus, oak, maple and poplar.

Water is adjusted to 60 to 65 percent and pH to 5.5 to 6.0 using gypsum. Note how different that is from button mushroom compost at pH 7.2 to 7.8. Shiitake wants an acidic substrate.

Sawdust is soaked first. The folder gives 16 to 18 hours; the 2011 manual says at least two days. Wheat bran soaks for about three hours. Mix all ingredients thoroughly.

Then move fast. DMR says fill the bags at 1.5 to 2 kg immediately after mixing, because fermentation and contamination start otherwise, and the manual keeps the gap between mixing and sterilising under six hours. Use heat resistant polypropylene bags.

Sterilisation is in an autoclave at 22 psi for 1.5 to 2 hours. After cooling, grain spawn goes in at 3 percent on a dry weight basis under aseptic conditions.

Shiitake blocks incubate far longer than oyster bags. The folder gives 60 to 80 days at 22 to 26 C, 500 to 1000 lux and 65 to 70 percent humidity, on a cycle of 4 hours light and 20 hours dark. The manual's table stretches this to 50 to 120 days at 20 to 30 C.

The block passes through visible stages. A thick mycelial coat forms at 6 to 8 weeks. Bumps, which are clumps of mycelium, appear at 9 to 10 weeks. Then the surface browns and the coat hardens. The bag is removed once the block is a third to half browned, with core moisture near 80 percent.

Induction is a short, deliberate change: 2 to 4 days at 10 to 20 C with 500 to 1000 lux and 85 to 95 percent humidity. DMR's alternative is the cold water shock at 4 to 6 C for 10 to 20 minutes.

Fruiting runs 7 to 14 days. The folder gives 12 to 25 C at 60 to 80 percent humidity and notes that the band is strain dependent; the manual narrows it to 12 to 18 C.

Then rest the blocks 7 to 21 days at 22 to 26 C in darkness. A dry spell after harvest prevents contamination, and a water bath restores the moisture the block lost.