Most first grows fail in the grain stage: a weak injection, a cold cupboard, a contaminant that got in with the needle. Colonised grain spawn removes that stage. It is sterilised grain that has been inoculated in a lab and run right through with the species you chose, so what arrives is a bag of vigorous, fully white spawn that goes straight into substrate. It costs more than an empty grain bag, and it buys you three weeks and a much higher chance of success.

Using it straight away

1. Break it up outside first

   Before opening anything, knead the sealed bag until the kernels are separate. It is far easier through the plastic.

2. Match the substrate

   Oysters: CVA or CVWA coir blends, or hardwood. Lion's mane, shiitake, king oyster, reishi: wood lovers substrate.

3. Spawn in clean air

   In a still air box or in front of a flow hood, open the spawn and the substrate, mix at 1:2 to 1:4 for coir or 1:4 to 1:5 for hardwood, and pack a tub or re-seal the substrate bag as a block.

4. Colonise, then fruit

   Dark, 20 to 24°C, until white. Then humidity, fresh air and light. The species guides have the numbers.

Keeping it alive until you are ready

Spawn is a living colony eating a finite bag of grain. Use it within a week of arrival if you can. If you cannot, the fridge holds it for two to three weeks; let it come back to room temperature for a day before you spawn with it, because cold spawn is sluggish. Never freeze it, never leave it in a hot car or parcel locker, and never open it to look.

Grain to grain: one bag becomes five

Here is the lever that makes a season cheap. Colonised grain can inoculate fresh sterilised grain far faster than a syringe can, because every kernel is already a colony. Drop a few handfuls into a fresh sterilised grain bag, shake, and that bag is fully white in a week. Repeat across five or ten bags and one purchase of spawn becomes enough for a dozen tubs.

1. Set up a still air box

   A clear tub with arm holes, wiped inside with 70% alcohol, with the fresh grain bags, the spawn bag, scissors and gloves inside before you start. SAB guide.

2. Open the fresh bag high

   Cut the fresh grain bag open just below the seal, keeping the opening as small and as high as possible.

3. Transfer fast

   Open the spawn bag, scoop or pour two to three handfuls (roughly 100 to 150g per 1kg of fresh grain) into the fresh bag. Keep hands and the opening inside the box the whole time.

4. Re-seal

   Fold the top of the fresh bag over twice and clip or tape it, or use an impulse sealer if you have one. Shake to distribute.

5. Label and wait

   Five to ten days at room temperature and the new bag is spawn. Shake at a third colonised.

Why not just inject every bag?

You can, and for one or two bags a syringe is simpler. Grain-to-grain wins when you want many bags from one culture, or when a species is slow from liquid: lion's mane and shiitake that crawl from a syringe fly from a handful of spawn.

Written by the Aus Myco Kingdom crew. Everything here is general growing information for gourmet and medicinal species; your room, your climate and your culture will have the final say.