Description
Buy this spawn if you are mixing your own sawdust and soy hull blocks and want a colonisation you can leave alone for two months. Expect a slow front, then a rapid finish once the culture has settled in.
Shiitake mycelium ages to a tan skin on mature grain. That is normal for the species and not a contamination signal, and it is one of the first questions we get asked about this jar.
Hold back a handful when you fill a block and sprinkle it over the top surface. A grain cap closes the surface against competitors while the rest of the block finishes.
What is in the box
- 1 colonised spawn container
- Breathable filter cap or patched lid
How to grow it
- Warm the jar or bag to room temperature and shake it to break the grain loose.
- Work in still air: a closed room, no fan, everything wiped down with alcohol.
- Mix at roughly 5-10% spawn to wet substrate, more if you want speed over economy.
- Incubate in the dark at the species temperature. Use within two weeks of arrival.
Care on arrival
Do not leave spawn in a hot car or on a sunny sill; heat kills a culture faster than contamination does. White, fluffy and smelling sweet is what you want to see.
Specifications
| SKU | MGS-SPN-SHI |
|---|---|
| Medium | Whole rye berries |
| Coverage | One jar inoculates about four 5 lb bags |
| Storage on arrival | 2-4 C, dark, use within 14 days |
| Will it fruit on its own | No. Spawn needs substrate |
| Fruiting temperature | 12-21 C |
| Colonisation temperature | 20-26 C |
| Colonisation time | 8-14 weeks on supplemented sawdust blocks |
| Time to first pins | 7-14 days after a cold and dry rest |
| Relative humidity | 85-92% relative humidity |
| Substrate it wants | Supplemented hardwood sawdust (Master’s Mix) or inoculated oak logs outdoors |
| Format | Colonised culture for adding to substrate |
Questions
What conditions does Shiitake need in fruiting?
Fruit at 12-21 C with relative humidity of 85-92% relative humidity. Indirect light; dappled shade outdoors. Moderate fresh air exchange
How many flushes will a shiitake block give?
Most indoor growers see two to four usable flushes from a 5 lb block before the substrate collapses to sawdust. Soaking between flushes and resting the block cool and dry is what keeps the count up. It is not a guaranteed number.
Will a jar of spawn grow mushrooms by itself?
No, and this is the most common ordering mistake on the internet. Spawn is culture: it has to be mixed into substrate, which is the food. Buy a substrate bag or a 40 lb bag of pellets alongside it.
How much spawn do I need?
Roughly 5-10% of the wet substrate weight. One 3 lb jar covers about four 5 lb bags; a 5 lb bulk bag covers around eight.
What does Shiitake taste like, and how do I cook it?
Deep umami, firmer texture, better when cooked. Give the fruit a dry, hot pan rather than a wet one.
Is this a good first grow?
Honestly, no. Shiitake wants a steady 12-21 C fruiting range and generous fresh air, and it shows its faults immediately. Start with Pink Oyster or Lion’s Mane, then come back to this when you have read your own room’s temperature swings.
Live goods are packed in an insulated mailer with a cold pack and dispatched Monday to Wednesday. Standard shipping is free over $95.







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