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White Shimeji Agar Plate Culture FAQs
What is a White Shimeji mushroom agar culture?
A White Shimeji agar plate culture contains living mycelium from the White Shimeji mushroom, Hypsizygus marmoreus, growing across a nutrient-rich agar medium. It provides a clean starting point for expanding the culture, inoculating sterilised grain or making further agar transfers.
White Shimeji mushrooms are a hardwood-loving gourmet species known for their pale caps, crisp stems and dense, attractive clusters.
How do I use a White Shimeji agar plate?
Work in the cleanest environment possible, ideally in front of a laminar flow hood or inside a still-air box.
Using a sterile scalpel:
Cut a small wedge from the healthy outer edge of the mycelium.
Transfer the agar wedge into sterilised grain or onto a fresh agar plate.
Seal the receiving container immediately.
Allow the White Shimeji mycelium to colonise fully before transferring it to a hardwood-based fruiting substrate.
Additional culture transfers can be made using our Light Malt Extract Agar Plates.
Can I inoculate sterilised grain directly from the agar plate?
Yes. Small wedges of colonised White Shimeji agar can be transferred directly into sterilised grain.
Adding several small agar wedges at different points inside the grain bag can help the mycelium establish more evenly. Always use sterile tools and minimise the amount of time the bag or plate remains open.
Once the grain is fully colonised, it can be used as White Shimeji grain spawn for inoculating a suitable hardwood fruiting substrate.
What substrate is suitable for White Shimeji mushrooms?
White Shimeji grows best on hardwood-based substrates, particularly supplemented hardwood sawdust made from hardwoods such as oak or beech.
After sterilised grain has fully colonised, it can be transferred into a Sterilised Hardwood Mushroom Grow Bag. These ready-to-inoculate bags contain hardwood substrate supplemented with wheat bran.
Growers preparing their own fruiting bags can also use our 2 kg Hardwood and Wheat Bran Bulk Substrate. It provides a nutrient-rich hardwood growing medium suitable for White Shimeji once inoculated with fully colonised grain spawn.
How long does White Shimeji mycelium take to colonise grain?
White Shimeji mycelium is generally slower than oyster mushroom mycelium. A sterilised grain bag may take approximately three to six weeks to colonise, although the exact time depends on:
The amount of agar transferred
The type and quantity of grain
Incubation temperature
Moisture levels
Sterile technique
The overall vitality of the culture
The grain should appear evenly colonised with healthy white mycelium before it is transferred to a hardwood fruiting substrate.
What temperature is best for White Shimeji mycelium?
White Shimeji mycelium generally colonises well at approximately 20°C to 24°C.
Keep the agar plate and inoculated grain away from direct sunlight, radiators and excessive temperature fluctuations. A Digital Thermometer and Hygrometer can help you monitor conditions in your growing area.
How should I store my White Shimeji agar culture?
Store the sealed White Shimeji agar plate in a refrigerator at approximately 2°C to 8°C until you are ready to use it.
Do not freeze the culture. Keep the plate sealed, clean and protected from repeated temperature changes. For the strongest growth, use the culture as soon as reasonably possible after delivery.
How long will the White Shimeji agar culture remain viable?
A properly sealed and refrigerated White Shimeji agar plate can remain viable for several months. However, cultures are best used while they are fresh and actively growing.
Every Artisan Mushrooms agar culture is made fresh to order to help provide maximum freshness, vitality and healthy mycelial growth.
Please allow up to two weeks before dispatch while your culture is prepared, colonised and checked.
What does healthy White Shimeji mycelium look like on agar?
Healthy White Shimeji mycelium is normally white and may appear:
Fine and wispy around the growing edge
Dense and cotton-like as it matures
Rope-like or slightly rhizomorphic
Uneven around the original transfer point
Thicker across older areas of the plate
Appearance can vary depending on the age of the culture, agar recipe and incubation conditions.
What are the signs of contamination on an agar plate?
Possible signs of contamination include:
Green, black, pink or brightly coloured growth
Wet or greasy-looking patches
Unusual bacterial slime
Strong yellow or brown discolouration
Growth that appears separate from the intended mycelium
Do not open or use a plate that appears contaminated. Keep it sealed and contact Artisan Mushrooms with clear photographs.
Can I make more agar plates from this culture?
Yes. A small piece of healthy White Shimeji mycelium can be transferred onto a fresh agar plate to expand and preserve the culture.
Use a sterile scalpel and transfer a small wedge from the clean, actively growing outer edge of the colony. Our Light Malt Extract Agar Plates are suitable for making additional White Shimeji culture transfers.
Is White Shimeji agar suitable for beginners?
White Shimeji can be grown by beginners, although it is slower and requires more patience than common oyster mushrooms.
Beginners should use:
A still-air box or laminar flow hood
A sterile scalpel
Gloves
Surface disinfectant
Clean receiving plates or sterilised grain
Careful, deliberate movements
Good sterile technique is essential when working with any mushroom agar culture.
How long does White Shimeji take to fruit?
After the grain and hardwood substrate have fully colonised, White Shimeji often requires an additional maturation period before fruiting. Pins may begin forming within approximately two to four weeks after suitable fruiting conditions are introduced.
White Shimeji generally benefits from cool fruiting temperatures, high humidity, moderate light and regular fresh-air exchange. Fruiting times vary depending on the strain, substrate, block maturity and growing environment.
Can I buy White Shimeji as a liquid culture instead?
Growers who prefer syringe inoculation can browse our full collection of mushroom liquid cultures.
Liquid culture is convenient for inoculating grain through an injection port, while agar cultures are particularly useful for making clean transfers, expanding genetics and visually inspecting mycelial growth.
