Pasteurised Coco Coir Mushroom Bulk Substrate | Williams Co Supplies
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Pasteurised Coco Coir Mushroom Bulk Substrate

Pasteurised Coco Coir Mushroom Bulk Substrate

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 Ready to use
 Field capacity 
 Pasteurised & heat-sealed
Backed by our 30 day money back guarantee

How much do I need?

We recommend a substrate depth of around 8cm at a 4:1 substrate to spawn ratio. Here are some quick conversions to help.

 Grain Spawn
Substrate Needed
250g ~1 litres
500g ~2 litres
1kg ~4 litres

Click here to work out how much substrate you need with our substrate calculator.


1kg grain = 2 litres
700g substrate = 2 litres

How do I use it?

This pasteurised substrate is ready to use, making the whole spawn to bulk process extremely easy. Simply open up the heat sealed bag and mix with your colonised grains. Each batch is made to order to ensure freshness.


    • Coco Coir
    • Food Grade Gypsum
    • Vermiculite

    Casing Layer Option

    Click here for more information

    Delivery Information

    Your order will be sent with Royal Mail or Parcelforce, you will receive an email once it has been dispatched. Orders are dispatched within 2 days unless stated otherwise. Plain packaging.

    30 Day Money Back Guarantee

    We offer a money back or replacement guarantee on all of our products. To claim your replacement or refund please send us photos of the issue to: and we will do our best to help you.