CV Prime: coir and vermiculite substrate

What is CV Prime?

CV Prime is our ready-to-use CV substrate: coco coir and vermiculite, pasteurised and hydrated to field capacity, packed in a filter-patch grow bag. It is the original MushRealm ACS recipe, the exact blend ACS runs in every grow. Open the bag, mix in fully colonised grain spawn, close it up and let it run. No buckets, no boiling water, no guessing at moisture.

Why coir and vermiculite

• Coir (coconut fibre) holds water well and offers little easy food for competing moulds, which makes it a forgiving bulk substrate.
• Vermiculite keeps the mix open and airy and holds moisture where the mycelium needs it.
• Field capacity out of the bag: as wet as it can be without free water pooling, so it stays moist through colonisation and fruiting.

The background reading: what is CV substrate, CV vs CVG and field capacity explained.

Why pasteurised, not sterile?

Many ready-made substrates are sold sterilised. CV Prime is pasteurised on purpose. Coir and vermiculite carry very little free nutrition, so they do not need sterilising the way grain does: pasteurisation knocks back competitors and leaves a mix that colonises cleanly once a strong grain spawn goes in. Keep it sealed, cool and dark until you use it, use it soon after it arrives, and mix in fully colonised grain with clean hands and tools. More in pasteurised vs sterilised substrate and how to choose a mushroom substrate.

Which mushrooms grow on CV

How to use it

1. Colonise your grain spawn fully first.
2. Wash your hands and wipe the bag and scissors with alcohol.
3. Cut open the top, add the colonised grain at about 1 : 2 (one 1 kg grain bag per 2.2 kg CV Prime bag) and mix it through evenly.
4. Fold the top closed and keep it at 21 to 24°C (70 to 75°F) until it is white all through, typically 10 to 14 days.
5. Give it fresh air, high humidity (85 to 95%) and indirect light to fruit, then harvest.

The full walkthrough is in how to grow oyster mushrooms on CV substrate, and mushroom fruiting conditions covers the fruiting stage.

How much do I need?

One 2.2 kg bag fills one typical grow. Planning several? The spawn to bulk calculator works out the grain and CV Prime for any number of grows and the cheapest way to buy them.

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.