Shiitake Liquid Culture

Description

This is a 10 ml syringe of living shiitake mycelium in a sterile nutrient broth. Each batch is grown from a single isolated culture, so the genetics stay the same from syringe to syringe. That matters for shiitake, because commercial growers rely on known strains for steady yields. You inject it straight into sterilized grain, and it usually shows growth within about a week.

Shiitake has a tan to dark brown cap, often with white flecks at the rim, cream gills, and a tough, fibrous stem. Caps crack in dry weather, which some growers prize.

Flavor and kitchen uses

Shiitake is savory and rich, with a meaty bite once cooked. The caps stay firm in long cooking. The stems are too tough to eat, so save them for stock. Shiitake dries well and rehydrates for soups and sauces.

• Simmer in miso soup or a clear broth.
• Slice into stir-fries with garlic, ginger and soy.
• Braise with greens or noodles.
• Roast whole caps with sesame oil until the edges crisp.

Cook shiitake well. A small number of people get an itchy skin rash after eating it raw or undercooked.

Growing profile

Parameter	Shiitake
Colonization temperature	70 to 75°F (21 to 24°C). Keep below 80°F. Dark at first, then indirect light while the block browns.
Fruiting temperature	55 to 65°F (13 to 18°C), after a cold soak or a cold rest in the fridge
Humidity	85% or higher
Light	Indirect light, bright enough to read by
Fresh air	Gentle, steady exchange
Days to colonize	6 to 12 weeks on a sawdust block, then 4 to 7 more weeks until the block turns mostly brown and bumpy. Logs take 6 to 18 months.
Days to first harvest	10 to 21 days after the cold shock. Pins show in 3 to 7 days and are ready 7 to 14 days later.
Syringe to first harvest	About 3 to 5.5 months on blocks, and about a year on logs (our estimate)
Substrates	Fresh-cut oak logs 3 to 6 inches thick (also maple, beech, hornbeam, sweetgum). Indoors, hardwood sawdust with 10 to 20% wheat bran.
Typical yield	0.3 to 1.4 lb per sawdust block in a Cornell trial, depending on strain. Logs give about 0.25 to 0.5 lb per flush, 2 to 3 flushes a season.

Difficulty: Intermediate. Starting from a culture takes the guesswork out of the genetics, but shiitake is still slow. Sawdust blocks need a long incubation and must brown before they fruit. Cornell’s growers found that moving blocks to fruit too early, or letting them chill too soon, sharply cuts yield. Logs are the easier route for a first grow, though they take about a year to start fruiting.

Tips for success

• Shake the syringe hard for 30 seconds to break up the mycelium. Wipe the injection port and needle with alcohol, then inject 1 to 2 ml per quart jar of sterilized grain. One syringe covers about 5 to 10 jars.
• For logs, expand grain spawn into sawdust spawn first, then pack the holes and seal them with wax.
• Do not rush blocks. Cornell waits until a block is about 75% brown and bumpy before fruiting it.
• To trigger fruiting, soak blocks in cold water for 5 to 12 hours or refrigerate them for 12 to 24 hours. Soak logs for about 24 hours.
• Let a block rest and dry for a week or two between flushes before you soak it again.
• Harvest when the caps are mostly open but the edges still curl under.

Healthy culture or contamination. A healthy culture has clear to slightly hazy broth with white, cloud-like wisps or clumps of mycelium that settle when the syringe sits and spread out when you shake it. It smells mild or earthy. Warning signs are broth that turns evenly milky or murky and stays that way, a sour or rotten smell, a film or slime on the surface, or green, black or pink growth. If you are unsure, put a drop on an agar plate before you inoculate grain.

Kit includes

• One 10 ml luer-lock liquid culture syringe of living Lentinula edodes mycelium in sterile nutrient broth.
• One sterile needle.
• One alcohol prep pad.

To use it you also need sterilized grain jars or grain bags with an injection port.

Storage

Refrigerate the syringe at 2 to 8°C (36 to 46°F) as soon as it arrives, and keep it in the dark. Do not freeze it. Use it within 3 months for the fastest, strongest growth. The mycelium stays alive longer in the fridge, but it slows with age. Before use, let the syringe warm to room temperature for a few hours and shake it well.