PASTEURISED
CV Prime substrate
£19.992.2 kg
The original MushRealm ACS recipe, the exact blend ACS runs in every grow: coir and vermiculite, pasteurised and hydrated to field capacity. Mix in colonised spawn and fruit straight from the bag.
1KGSTERILISED
Grain spawnOats UK menu
Sterilised oat grain spawn
£14.99£14.99 per kg
The original MushRealm ACS recipe, the exact grain ACS runs in every grow: whole oats, fully hydrated, pressure-sterilised and sealed in a 0.2 µm filter-patch bag with a self-healing injection port.
- Recipe
- Original MushRealm ACS
- Grain
- Oats (whole oats)
- Prep
- Fully hydrated, pressure-sterilised
- Bag
- 0.2 µm filter patch + self-healing port
- Works with
- Oyster, lion’s mane, shiitake and most gourmet species
- Spawns
- 2 kg of CV Prime at 1 : 2
Weight
1
Most orders leave in 1 to 2 working days. Ships from the UK. Royal Mail tracked: £4.99, or £9.99 for large parcels.
Complete the growCV Prime substrate · 2.2 kg · £19.99
One grain bag spawns one CV Prime bag at about 1 : 2, the same pairing as our kits.
The details
The original MushRealm ACS recipe, the exact grain ACS runs in every grow: whole oats, fully hydrated, pressure-sterilised and sealed in a 0.2 µm filter-patch bag with a self-healing injection port.
- 1 kg sterilised oats grain
- 0.2 µm filter patch
- Self-healing injection port
How to use it
- Wipe the injection port with alcohol and inoculate through it with live mycelium of your chosen gourmet species.
- Let it colonise somewhere warm and dark. Shake once to spread it when about a third is white.
- When it is fully colonised, open it and mix it into CV Prime.
Your Grow Dashboard tracks every stage and reminds you when to air and mist.
Shipping and the guarantee
Ships within the United Kingdom by Royal Mail tracked. If a bag shows up contaminated or damaged in transit, send a photo within 7 days of delivery and we replace or refund it. Shipping policy · Returns and refunds.
Storage
Cool and dark. Use grain spawn promptly for the best results; substrate keeps for several weeks sealed. Do not freeze.
Intended use
A horticultural supply for growing gourmet mushrooms. This product contains no mushroom spores or cultures and is not for human or animal consumption. Read our intended use statement.
What you get
Sterilised whole oats, fully hydrated and pressure-sterilised in a 1 kg bag with a 0.2 micron filter patch and a self-healing injection port. This is the original MushRealm ACS recipe: the exact grain ACS runs in every grow. It arrives ready to inoculate, so there is no soaking, simmering, bagging or pressure cooking to do.
Included and not included
| Included | Not included |
|---|---|
| 1 kg of hydrated, pressure-sterilised whole oats | Live mycelium of your chosen species (you add it) |
| A 0.2 micron filter patch so the bag can breathe | A pressure cooker (you will not need one) |
| A self-healing injection port | Bulk substrate: CV Prime is sold on its own or in the kit |
Why whole oats
Whole oats are a dependable spawn grain: consistent, easy to break up and good at holding water without turning to mush. Plenty of kernels per kilo means plenty of inoculation points, for a fast, even colonisation and a clean break-up when you spawn to bulk.
| Grain | Why growers like it | Watch out for |
|---|---|---|
| Whole oats (our UK choice) | Holds water well, consistent, breaks up cleanly | Can clump if over-hydrated, which is why we stick to the ACS recipe |
| Rye | Widely sold, firm kernels | Can burst and go mushy if overcooked |
| Milo (our US choice) | Small kernels, lots of inoculation points, tough hull | Harder to find in the UK |
More on the choice in oats vs rye and oats vs milo.
Which gourmet mushrooms it suits
| Species | Spawn it into | Notes |
|---|---|---|
| Oyster (blue, pearl, pink, golden) | CV Prime or straw | The easiest place to start |
| King oyster | Supplemented hardwood sawdust | Likes a cooler fruiting room |
| Lion's mane | Supplemented hardwood sawdust | Harvest before the spines yellow |
| Shiitake | Hardwood sawdust blocks or logs | A longer run, worth the wait |
| Wine cap | Wood chip beds outdoors | A garden bed favourite |
How to use it
- Wipe the injection port with 70% alcohol and work somewhere clean and still.
- Inoculate through the self-healing port with live mycelium of your chosen gourmet species: a colonised grain transfer, a commercial grain spawn of that species, or a liquid inoculant.
- Keep the bag at 21 to 24°C (70 to 75°F), out of direct sun.
- When about a third of the grain is white, break it up and shake to spread the mycelium.
- Once fully colonised, typically 2 to 4 weeks depending on species and temperature, mix it into CV Prime at about 1 : 2 or into the bulk substrate your species prefers.
Step-by-step help: how to inoculate grain spawn bags, how long grain spawn takes and the spawn to bulk guide. The spawn to bulk calculator works out how many bags you need.
Storage
Keep unopened bags somewhere cool and dark and use them promptly: sterile grain is at its best soon after it arrives. Do not freeze.
Shipping and the guarantee
Ships from the UK in 1 to 2 working days by Royal Mail Tracked: £4.99, or £9.99 for large or heavy parcels. If a bag arrives contaminated or damaged, send us a photo within 7 days of delivery and we replace or refund it. See shipping and returns.
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What growers say
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Complete the grow
See the whole menu Pairs well with
MATCHED PAIR
Grow kit bundle
£27.99Starter kit
One 1 kg oat grain bag and one 2.2 kg CV Prime bag, the 1 : 2 pairing our kits are built on.