Organic Blue Oyster Mushroom Grain spawn
- 🍄 MYCELIUM ON GREY OYSTER MUSHROOM SPORES: Pleurotus ostreatus, an essential variety for mushroom cultivation.
- 🌱 EASY AND VERSATILE: Works with a variety of substrates, such as straw, sawdust, or logs.
- 💪 HARDY AND PRODUCTIVE: Fast-growing, hardy, and generally produces abundant yields.
- 🍽️ DELICATE FLAVOR: A mushroom prized in cooking for its tender texture and balanced flavor.
- 🌍 LOCALLY GROWN AND ORGANIC: Certified BE-BIO-01 by Certisys.
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To grow your oyster mushrooms:
Gray Oyster Mushroom “Blue Oyster” – Pleurotus ostreatus KB1 / Columbinus
A highly productive mycelium that is easy to cultivate and suitable for a wide range of substrates, including straw, sawdust, logs, and other lignocellulosic materials.
The strain produces beautiful gray caps and can take on bluish hues when temperatures are cooler, particularly around 10 to 15°C at the start of fruiting.
Native to the temperate forests of Europe, oyster mushrooms grow naturally on dead tree trunks and branches. They are most commonly found in the fall and late winter.
Today, it is one of the most widely cultivated mushrooms in the world, prized for its flavor, rapid growth, and ease of cultivation.
Characteristics of the strain
- Caps: typically 5 to 15 cm
- Color: light gray to dark brown, depending on conditions
- Characteristic: bluish hues at low temperatures, especially at 10–15°C
- Texture: more tender than many oyster mushrooms, with fairly thick stems
- Key advantage: excellent productivity and good shelf life
❄️ Storage: Store the mycelium in the refrigerator, ideally between 1 and 4°C.
For best results, use it within one month of receipt.
👉 See also: How to use our mycelium
Our Commitment to Quality
We produce our mycelium under laboratory conditions to ensure varietal purity and optimal quality.
Our mycelia are organically produced and certified BE-BIO-01 by Certisys under the Belgian Organic Agriculture program.
🌱 Growing conditions
Oyster mushrooms can be grown year-round. They generally grow best at temperatures between 12 and 20°C, with a cooler period to encourage the formation of primordia.
During the incubation period, maintain high humidity until the young mushrooms appear, then stabilize the environment with good ventilation.
Tip from La Mycosphère: To trigger a good fruiting, start with a cooler phase at 10–15°C and 95–100% humidity until primordia form, then maintain humidity at around 85–95% during growth.
harvest Harvest the clusters by hand, gently twisting them, before the edges of the caps turn brown and curl up. Remove any remaining stems and maintain humidity to promote the next flush.
🛠️ Recommended growing media
For indoor growing
The oyster mushroom is very versatile. It grows well on pasteurized straw, pasteurized sawdust, and other lignocellulosic materials.
For a simple and consistent result, we recommend:
- Organic straw pellets: Add about 1 teaspoon of lime and 2 liters of cold water per kilogram of pellets.
- Sawdust-based substrate: particularly suitable for wood-decaying fungi.
Outdoor cultivation
Oyster mushrooms can also be grown on logs or using the mulch method. For log cultivation, it is best to use mycelium on dowels.
📊 Growing conditions
Inoculation rate: 5 to 10% mycelium on grains relative to the weight of the moist substrate.
| Phase | Temperature | Duration | Humidity | Light | CO₂ | Fresh air |
|---|---|---|---|---|---|---|
| Incubation | 20–24°C | 2–3 weeks | - | - | - | - |
| Formation of primordial cells | 10–15°C | 4–7 days | 95–100% | 600–1,000 lux | 500–800 ppm | 4 to 8 flights per hour |
| fruiting | 10–20°C, ideally around 15°C | 5–10 days | 85–95% | 600–1,000 lux | 500–800 ppm | 4 to 8 flights per hour |
📚 Estimated data from *Growing Gourmet and Medicinal Mushrooms* by Paul Stamets. Results may vary depending on the strain, substrate, humidity, ventilation, and growing conditions.
📈 Productivity
The gray oyster mushroom is a highly productive variety. On average, you can expect 200 to 350 grams of fresh mushrooms per kilogram of moist substrate, over 2 to 3 harvests.
FAQ – KB1 Gray Oyster Mushroom
What type of growing medium should I use?
The oyster mushroom is versatile: it can be grown on pasteurized straw, pasteurized sawdust, and other lignocellulosic substrates. For simple and consistent results, organic straw pellets work very well.
How much does it produce?
On average, allow 200 to 350 grams of fresh mushrooms per kilogram of moist substrate, over 2 to 3 harvests.
What is the ideal temperature?
For best results, aim for a temperature of 12–20°C in general, with a cooler initial phase at 10–15°C to trigger fruiting.
Do we need some light?
Yes. Soft lighting helps produce beautiful caps. Aim for about 600–1,000 lux during the induction and fruiting phases.
What inoculation rate should be used?
We recommend using 5 to 10% grain mycelium relative to the weight of the moist substrate.



