Buy Vermiculite for Mushrooms – pre-sterilised and Ready to Use. Our premium vermiculite is the perfect choice for mushroom growing, weather you are using PF tek jars, bulk substrates or casing layers. Sold in convenient 1000ml pre-sterilised bags. This vermiculite saves you time and reduces contamination risks. Vermiculite is essential in mushroom cultivation because it retains moisture, prevents contamination and acts as a contamination barrier. Ideal for beginners and advanced mycologists alike, it’s a trusted substrate component for PF tek, casing layers and monotubs. Vermiculite for PF tek (Brown rice flour + Vermiculite) Best Vermiculite for PF tek: It is best to use Dry vermiculite for the PF tek method. How it is used: The substrate mix is usually 2 parts vermiculite, 1 part brown rice flour and 1 part water. Purpose: Vermiculite is the bulk of the mix, giving the mushroom substrate structure and Moisture holding capacity. Extra uses: A dry vermiculite casing layer is added under the lid of PF tek Jars as a contamination barrier whilst colonising. Colonised PF tek cakes are rolled in dry vermiculite to help fruiting and pin formation. Vermiculite for mushroom Casing Layers How is a casing layer used: A layer of moist vermiculite is spread over colonised grain or bulk substrate. Why is vermiculite used for casing layers: Improves water retention, protects the substrate from water sprays and gives baby mushroom pins a moist place to grow from. Best for: Monotubs, trays or larger grow setups. Sterilised Vermiculite for Mushroom growing Our product is bagged and arrives fully sterilised. Dispatched with fast UK and International Delivery. How to Sterilise Vermiculite? Vermiculite itself is an inert mineral, meaning it does not contain nutrients that would feed contaminants However: It can still carry mold spores, bacteria or dust from handling. When mixed with nutrients (Brown rice flour, manure, compost or grain), any unsterilised vermiculite becomes a vector for contamination Sterilise in qrt jars or 1 Litre bags @15psi for 90mins Common Vermiculite sterilisation methods Making Dry Vermiculite Bake the vermiculite in the oven at 180-200c for 60-90mins. Spread over a baking tray and cover loosely with aluminium foil. Use as soon as cooled. Making Wet vermiculite Place vermiculite into a bag. Pour boiling water over the vermiculite and insulate until cool. This will pasteurise the vermiculite and will be good for ten days. Try the best vermiculite for growing mushrooms today with fast UK and international delivery. Read our full Vermiculite vs Perlite guide for a side-by-side comparison and the standard CVG bulk substrate recipe.