Blue Oyster CNS mushroom grain spawn is a fully colonised spawn ready to inoculate bulk substrates. It produces large clusters of blue caps which fade to a silver blue at full maturity. This strain is from Cap'n'Stem Mushrooms in the USA and is their best selling commercial blue oyster strain. It performs well on Master's Mix and supplemented hardwood sawdust substrates but is susceptible to bacterial blotch if grown on pasteurised substrate. Steam sterilisation of the substrate is recommended or grow at cold temperatures to avoid bacterial blooms.
Blue Oyster CNS Mushroom Grain Spawn
Sale price
$45.00
Tax included
Strain characteristics
Species: Pleurotus ostreatus
Cap colour: Silvery blue
Cap size: Large
Growth rate: Fast (3-4 weeks from inoculation to harvest)
Best substrates: Master's Mix, supplemented hardwood sawdust
Fruiting temperature: 10-16°C (critical for pin formation of this strain)
Fruiting humidity: 85-90% humidity
Difficulty: Beginner to Intermidiate
Best suited to: Commercial growers seeking fast, high yields
Shipping & storage
- Grain spawn is heat sensitive during transit, we strongly recommend choosing Express Post for orders containing grain spawn.
- Unpack and refrigerate your spawn on arrival for all species except Pink Oyster.
- Spawn is alive with mushroom mycelium and should be used as soon as practical for best results.
- You can store grain spawn refrigerated for 3-6 months.
- We ship Australia-wide.
For more information please visit our Shipping & Delivery Page.
CULTIVATOR'S TIPS
Why grow this variety?
If you're looking for a heavy hitting Blue Oyster strain then this CNS Blue Oyster strain is for you.
It is a consistent, fast grower that produces big clusters of meaty caps. In our experience, this strain consistently produces first flushes of around 500g from a 2kg Master's Mix substrate block under favourable growing conditions.
To trigger pin formation, this strain requires cooler temperatures below 16°C. For best results, grow it in a climate-controlled fruiting room or seasonally during the cooler months of autumn and winter, depending on your local climate.
How to use grain spawn
Mushroom grain spawn is used to transfer mushroom mycelium into a bulk substrate, a process known as inoculation. Grain is the industry standard for spawn production, with wheat, rye, millet and sorghum commonly used. At Little Acre, we use Australian-grown wheat grain.
Once mixed through a suitable substrate, the mycelium colonises the material, eventually producing mushrooms. Grain spawn itself is not intended as a fruiting substrate, as it lacks the moisture retention and structural components needed for strong mushroom yields.
Common bulk substrates include pasteurised straw, sugarcane mulch, hardwood sawdust and pelletised blends such as Master's Mix, one of the most popular substrates for growing gourmet mushrooms. Depending on the substrate, preparation may involve pasteurisation or sterilisation before inoculation.
After preparing your substrate, mix in the grain spawn thoroughly and allow the mycelium to colonise. As with all mushroom cultivation, clean working practices are essential to minimise contamination and achieve the best results. Inoculations should ideally be performed in front of a laminar flow cabinet or inside a still air box to prevent contamination.
Choosing your growing method
DIY Grow Blocks
Best for growers who want to learn the full process and make their own substrate.
Our Home Growing Supplies Pack includes everything you need to make up to 10 mushroom grow blocks using the hot water pasteurisation method. The pack include:
- grain spawn
- pelletised substrate
- mushroom grow bags
- hydrate lime
- zip ties
- detailed instructions
This is the most cost-effective way to produce multiple grow blocks and is ideal for hobby growers wanting a hands-on cultivation experience.
Ready-to-grow mushrooms
Best for growers who want the simplest path to growing mushrooms.
Our ready-to-fruit grow blocks arrive fully prepared and colonised. Simply place the block into the correct fruiting conditions and watch mushrooms grow!
No substrate preparation, pasteurisation or inoculation required. These blocks are ideal for beginner growers who want to master fruiting a variety of mushrooms.
Grow at commercial scale
Best for growers producing mushrooms for markets or wholesale sale.
Our grain spawn is trusted by mushroom growers across Australia, from small-scale farms through to commercial operations. Our spawn is produced to deliver reliable colonisation, consistent performance and strong yields.
We offer wholesale pricing for ongoing farm customers, as well as bulk discounts or larger orders such as our Big Spawn Box.
FAQs
What is the difference between Blue Oyster CNS and other Blue Oyster strains?
The Blue Oyster CNS strain is a commercial strain bred for fast colonisation and big yields. To get the most out of this strain we recommend using steam pasteurisation or sterilisation to ensure bacteria is removed from your substrates as it is prone to blotch, especially in warmer temperatures. For that reason we'd recommend it for commercial growers. Beginner growers or home growers are recommended to use our standard Blue Oyster strain or Blue Shimeji which are more suited to pasteurisation methods of substrate preparation.
What are the ideal growing conditions for Blue Oyster CNS?
The ideal growing conitions Blue Oyster CNS are:
Fruiting Temperature: 10°C - 16°C
Fruiting Humidity: 85 - 90%
Fruiting CO2: 500 - 800ppm
It is critical to have cool temperatures under 16°C to initiate pin sets for this strain. If you can't achieve cold temperatures but want to grow a blue coloured oyster mushroom then we would recommend Blue Shimeji.
