Q
does this come with grain my killy
A
The spawn itself is grain based.
Home / Mushroom Cultivation / Spawn & Substrates / Shiitake SpawnJar™
Live spawn
Spawn & Substrates
Shiitake SpawnJar™
A jar of grain fully run through with living shiitake mycelium, ready to mix into hardwood sawdust and grow on. This is the spawn step, not a finished kit.
£44.95
Out of stock
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Sealed and inspected before it leaves us. Use within a few weeks for best vigour.
Live culture
Lentinula edodes mycelium on sterilised grain
Lentinula edodes mycelium on sterilised grain
Weighs in
One quart of colonised grain per jar
One quart of colonised grain per jar
Keeps
Refrigerate, sealed; use within a month or two for best vigour
Refrigerate, sealed; use within a month or two for best vigour
SpeciesLentinula edodes
FormColonised grain spawn, one quart jar
Typical spawn rateAround 10 percent into bulk substrate (5 to 20 percent range)
Block colonisationAround two to four months (shiitake is slow)
Fruiting temperatureRoughly 13 to 21C, humid, with fresh air
Fridge lifeA month or two, often up to about four
ForIndoor sawdust or pellet blocks, not logs
The short version
Shiitake SpawnJar is a glass jar of sterilised grain inoculated with shiitake (Lentinula edodes) and left until the grain is fully run through with white mycelium. You use it as a head start: break it up, mix it into a larger batch of hardwood sawdust, and let the mycelium spread out across the new food.
It is a midway product for people who already grow. There is no fruiting block in here. You provide the bulk substrate, the colonising space and the fruiting conditions.
What it is
A jar of living shiitake grain
The jar holds sterilised grain colonised by shiitake mycelium until the grain is bound into a solid white mass. Shiitake is a hardwood mushroom, so the grain is only a carrier to multiply the culture. The real fruiting work happens later, once you have moved it onto wood.
Healthy spawn looks evenly white and smells faintly of fresh mushroom or damp wood. Any green, grey, pink or black patches, or a sour or off smell, mean it has picked up a contaminant and should not be used. Check the jar before you open it.
| Species | Lentinula edodes (shiitake) |
|---|---|
| Form | Colonised grain spawn in a sealed jar |
| Volume | One quart jar |
| Carrier | Sterilised grain (rye, millet or wheat type grains) |
| Use | To inoculate bulk hardwood sawdust, or expand into more grain |
How to use it
Mixing spawn into substrate
The usual route is to inoculate a hardwood substrate, most often supplemented sawdust or hydrated hardwood pellet (a common recipe is around 80 to 85 percent sawdust to 15 to 20 percent wheat bran), hydrated to roughly 60 to 65 percent moisture. Work clean, ideally in front of a still air box or flow hood, since this is the point where contaminants get in.
1
Break up the grain
Shake or loosen the colonised jar so the grain separates into individual pieces. Each loose, mycelium covered grain becomes a new starting point in the substrate.
2
Mix through the substrate
Add the spawn to your sterilised, cooled substrate and mix until it is spread evenly. Spawn rates usually run from about 5 to 20 percent by weight, with 10 percent a sensible starting point. More spawn colonises faster and resists contamination better. Stretching it thinner is slower and riskier.
3
Colonise in the dark
Seal in a filtered grow bag or container and keep warm and dark. Shiitake is slow. A block usually takes around two to four months to colonise fully, then often turns brown and forms a firm leathery skin as it matures before it will fruit.
4
Fruit it
Once the block has browned over most of its surface, shiitake fruits in cooler, humid, fresh air conditions. Fruiting commonly runs in the region of 13 to 21C with high humidity and good fresh air exchange. Many growers trigger pinning with a cold shock, soaking the block in cold water or chilling it for 12 to 24 hours. Conditions vary by strain, so follow a shiitake guide for your block.
One quart of grain spawn goes a long way. As a rough guide, a few pounds of grain spawn can inoculate well over a hundred pounds of sterilised sawdust, so a single jar covers several home sized blocks.
Storage
Keeping the jar alive
If you are not using it straight away, keep the jar sealed in the fridge. Refrigerated grain spawn stays viable for a month or two, often up to about four months, but vigour drops over time, so fresher is better. Keep it sealed and cool until the moment you inoculate. Do not freeze it, as ice crystals damage the mycelium. Let a cold jar come closer to room temperature before mixing so you are not shocking it.
What it is not
Not a grow kit, not for logs
This jar does not fruit on its own. There is no sawdust block, no bag and no fruiting tent in here. You supply the bulk substrate and the growing conditions.
Grain spawn is also not used for inoculating logs. Outdoor log growing uses sawdust spawn or plug spawn pressed or hammered into the wood. Use grain spawn for indoor sawdust or pellet blocks.
Common questions
Frequently asked
Break up the colonised grain and mix it through sterilised hardwood sawdust or pellet substrate, then colonise and fruit that block.
At around a 10 percent rate a quart of grain spawn covers several home sized hardwood blocks. As a guide, a few pounds of grain spawn can inoculate well over a hundred pounds of sawdust.
No. Logs need sawdust or plug spawn. Grain spawn is for indoor sawdust or pellet blocks.
Shiitake is one of the slower mushrooms. A block often takes two to four months to colonise, then browns and firms up before it will fruit. This is normal.
Often not. Shiitake commonly puts out a clear to amber liquid as it colonises and browns. If the mycelium still smells of mushroom or wood it is usually fine. A sour, rotten or sock like smell with slime means contamination.
Keep it sealed in the fridge and use within a month or two for best vigour. It can last up to about four months, but strength fades.
Even white growth and a fresh mushroom or woody smell are good. Any green, grey, pink or black patches, or a sour smell, mean contamination, so do not use it.
Ask the community
Questions and answers
Sold for legal gourmet mushroom cultivation. Inspect spawn before use and discard any jar showing signs of contamination.
We work hard to keep this information accurate and to cite reputable sources, but the occasional mistake can still slip through. Always check the product label and a current reference before relying on any figure for something important.