Description
Coco Coir Mushroom Grow Block – Compressed coconut coir brick that rehydrates to about 5-6 litres of open, low-nutrition substrate – the classic base for an oyster or wine-cap mix.
Coco Coir Mushroom Grow Block: what you get
Coco Coir Mushroom Grow Block arrives as 650 g, as the listing states it. Variations are sold as sealed or packed so it survives a courier, not just a shelf.
- 650 g, as the listing states it
- sealed or packed so it survives a courier, not just a shelf
- the same photograph as the listing, so you know what arrives

How to use coco coir mushroom grow block
Nothing about coco coir mushroom grow block is difficult, and almost every failed grow we hear about breaks at one of four points: moisture, temperature swings, still air being taken for clean air, and opening things too early. These four steps cover coco coir mushroom grow block in any shop-bought setup.
- Hydrate to field capacity: a handful squeezed hard should show moisture between the knuckles but not drip.
- Pasteurise straw and manure-free mixes at 60-80 C for 1-2 hours, or sterilise supplemented mixes at 15 PSI for 2.5 hours.
- Drain to the correct moisture before you inoculate – free water in the bottom of a bag is the classic contamination route.
- Inoculate while the substrate is still warm for grain spawn, or fully cool for liquid, and shake so spawn sits through the mass, not on top.
Storage and handling
If a pack has been wet, warm or sitting for an unexpected length of time, do not compound the loss by running it: use it on the next clean setup, or ask us before you inoculate.
Common questions
Do I need to buffer or rinse coir for mushrooms?
Rinse it and let it drain well. Unlike cannabis or vegetable growing, mushroom mycelium is tolerant of the salts in coir, but excess EC slows the run-in, so a fresh-water soak and drain is cheap insurance.
What do I mix it with?
About 25-40% by volume of something nutritious: pasteurised straw, hardwood pellets or supplemented sawdust. Straight coir will grow oysters eventually, badly.
How many bricks do I need for a first grow?
Two, plus a bag of straw or pellets and 3 lb of grain spawn, if you want to fill three 5 lb bags.
Usually ordered with Chopped Wheat Straw Mushroom Substrate – 10 lb and Master’s Mix Prepared Mushroom Substrate – 40 lb Bulk Bag. The substrate archive covers mixes, hydration and the pasteurise-versus-sterilise decision. Mushroom Substrate. For the technique side we keep FreshCap on substrates open while writing these pages, and the sanitation notes for the consumables follow the FDA Food Code.
Coir is not a complete mushroom food; it is structure and water holding. That is exactly why growers use it: mixed with a nutrition source, or used to bulk out a straw bed, it gives you a substrate that colonises evenly and does not go anaerobic in the middle of the bag.
What is in the box
- Compressed coconut coir brick that rehydrates to about 5-6 litres of open, low-nutrition substrate – the classic base for an oyster or wine-cap mix
- Dry and shelf-stable: store it closed, off a concrete floor, and out of the sun so it does not sour or take on mould before you use it
- Sized for home growers – one brick makes roughly two 3 lb hydrated bags on its own, or a top-up to a heavier mix
- No spawn or bags included; this is the raw material tier
How it works
- Rehydrate to field capacity: damp and heavy, with a few drops escaping when you squeeze a handful hard, not a stream.
- Pasteurise for straw and litter-based mixes (140-160°F for an hour or two) or sterilise supplemented sawdust blends at 15 PSI for 2-2.5 hours per 5 lb bag.
- Cool before inoculating, then mix spawn through evenly and bag or bed immediately.
What to expect from this grow
Substrate quality is the variable most home growers skip. Wet it properly, drain it properly, and do not let a batch sit in a warm bucket overnight before you sterilise it.
Specification
| Product type | Mushroom substrate |
|---|---|
| Stage | Substrate and amendments |
| Size | 650 g compressed |
| Shipped weight | 1.5 lb |
| Package size | 6 × 4 × 3 inches |
| SKU | MGS-0034 |
Part of our Mushroom Substrate range. Questions about this product? Email [email protected] or call +1 970-909-8532.




Reviews
There are no reviews yet.