King Trumpet Oyster Colonized Agar Plate
King Trumpet Oyster Colonized Agar Plate is backordered and will ship as soon as it is back in stock.
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Description
Description
A fully colonized King Trumpet Oyster (Pleurotus eryngii) agar plate, grown from our master culture and 1st-generation isolated genetics — the same strain we use in our King Trumpet liquid culture syringes and grow kits.
Each plate is produced at our Illinois lab on standard malt extract agar (MEA), fully colonized before it ships, and held in inventory rather than made to order, so it ships within 1 business day. Multi-item orders may take an additional 1–2 business days so we can pack everything together.
- 90mmPolypropylene dish
- ~18mLMEA agar
- 7–12 daysColonizes agar
- 55–65°FFruiting temp
- 1 dayShips within
Why growers pick King Trumpet
King Trumpet — also sold as King Oyster, King Brown, French Horn, or simply "eryngii" — is the largest and meatiest of the cultivated oysters. Instead of thin, fan-shaped caps, it grows thick, dense white stems topped with small tan caps, and the stem is the prize.
- Meat-like texture – stems stay firm and chewy when cooked; seared rounds are a well-known scallop substitute, and shredded stems work like pulled meat
- Long shelf life – 7–10 days refrigerated, far more forgiving than Golden or Pink Oyster for storing or selling
- Cool-to-moderate fruiting – fruits best at 55–65°F, filling the gap between Blue Oyster and the warm-weather oysters
- Heavy yields by weight – dense stems mean each flush weighs more than it looks
King Trumpet is a step up in difficulty from the other oysters — it wants a supplemented hardwood substrate and more attention to fresh air and humidity during pinning — which makes a clean, vigorous starting culture especially valuable.
What's included
- One 90mm polypropylene Petri dish, parafilm-sealed for sterility during transit
- ~18mL malt extract agar (MEA), our standard formulation for gourmet species
- Fully colonized with King Trumpet mycelium (typically 90–100% coverage at ship time)
- 1st-generation isolated genetics from our master culture
- Lab-inspected for contamination before it ships
When your plate arrives
- Inspect it within 24 hours. Minor condensation on the lid is normal and harmless.
- Store it cool and dark. Keep the sealed plate at 55–70°F until you're ready to use it.
- Work clean. Open the plate only under a still-air box or laminar flow hood.
- Make your transfer. Cut a small wedge, about the size of a pencil eraser, and move it to grain, liquid media, or fresh agar.
Shipping and storage: plates ship in insulated, padded packaging via USPS Priority Mail (typically 2–4 days in transit), with a cold pack included at no additional cost in summer months (May–September) or to hot-climate destinations. A sealed plate stays viable for 60–90 days at 55–70°F, or 6–9 months refrigerated at 35–40°F.
What you can do with one plate
- Transfer to grain – place a wedge onto sterilized grain (rye, our 5-grain blend, etc.); King Trumpet typically colonizes grain in 10–14 days
- Make liquid culture – drop agar wedges into sterile liquid media to produce your own LC
- Expand to more plates – divide one plate into 8–10 fresh plates to start a long-term genetic library
- Isolate strong sectors – move the most vigorous growth to a fresh plate to refine your genetics over generations
Shatterproof polypropylene plates
Every King Trumpet plate ships in a 90mm polypropylene Petri dish rather than the standard polystyrene. Polypropylene flexes under impact instead of cracking — and a cracked plate isn't just damaged, it's a contamination risk, since the crack breaks the parafilm seal. Our Lion's Mane plate is the one exception: it uses clear polystyrene for contrast against black agar.
Specifications
| Specification | Detail |
|---|---|
| Species | Pleurotus eryngii (King Trumpet, King Oyster, King Brown, French Horn) |
| Genetics | 1st-generation isolate from our master culture |
| Plate | 90mm polypropylene Petri dish, parafilm-sealed |
| Agar | ~18mL standard malt extract agar (MEA) |
| Sterility | Poured and inoculated under HEPA-filtered laminar flow |
| Mycelium appearance | Bright white, dense and cottony; less rhizomorphic than other oysters |
| Colonization speed on agar | Moderate — typically 7–12 days at 72–78°F |
| Preferred grain | Rye or our 5-grain blend |
| Fruiting substrate | Supplemented hardwood sawdust or masters mix — does not perform well on straw alone |
| Fruiting temperature | 55–65°F |
| Appearance | Thick white stems 2–6" tall with small tan-to-brown caps |
| Fresh shelf life | Long — 7–10 days refrigerated |
| Difficulty | Intermediate — more demanding than other oysters |
| Shelf life (sealed plate) | 60–90 days at 55–70°F; 6–9 months at 35–40°F |
| Ships | Within 1 business day |
Sterility and quality
Every plate is poured, inoculated, and inspected at Myco Labs under HEPA-filtered laminar flow, sealed with parafilm immediately after inoculation, and incubated in a dedicated clean room until fully colonized. Each plate is visually inspected for contamination before it's approved for shipment — if it doesn't look right, it doesn't ship.
Same genetics, other formatsWant the strain ready to inject? The King Trumpet liquid culture syringe carries the same genetics, and the King Trumpet grow kit lets you fruit the same strain without any lab work.
FAQ
Is King Trumpet the same as King Oyster? What about King Blue Oyster?
King Trumpet and King Oyster are the same mushroom, Pleurotus eryngii, also sold as King Brown, French Horn, or "eryngii." King Blue Oyster is a different mushroom: a large-capped strain of Pleurotus ostreatus that grows like a classic oyster, with big caps and short stems. If you want thick, meaty stems, King Trumpet is the one.
How does King Trumpet compare to Blue, Pink, and Golden Oyster?
All four are Pleurotus species, but King Trumpet is the odd one out. Blue, Pink, and Golden Oyster are fast, forgiving, and fruit happily on straw. King Trumpet is slower, prefers supplemented hardwood, and needs more attention during pinning, but it rewards you with dense, meaty stems and a much longer shelf life.
Can I grow King Trumpet on straw?
Not well. King Trumpet is a poor performer on pasteurized straw alone. For best results, use supplemented hardwood sawdust or a masters mix (roughly 50/50 hardwood sawdust and soy hulls), sterilized rather than pasteurized. Fruiting in a bag with a small opening at the top helps the stems grow thick and long.
How should I cook King Trumpet mushrooms?
The stems are the star. Slice them into thick rounds, score a crosshatch on each face, and sear in a hot pan with butter or oil for a scallop-style dish. You can also slice lengthwise and grill, roast at 425°F, or shred with a fork and pan-fry for a pulled-meat texture.
Can I use this plate to make grain spawn directly?
Yes — that's one of the most common uses. Under a still-air box or laminar flow hood, cut a small wedge (about the size of a pencil eraser) from the colonized plate and drop it into a sterilized grain spawn bag or jar. King Trumpet typically colonizes grain in 10–14 days at room temperature, a bit slower than the other oysters.
Are these the same genetics as your liquid culture syringes and grow kits?
Yes. Every King Trumpet plate is grown from our master culture and 1st-generation isolated King Trumpet strain — the same genetics in our King Trumpet LC syringes and grow kits.
How fast do these ship compared to other agar plate sellers?
Within 1 business day. Most agar plate sellers make plates to order, which can mean waiting 2–4 weeks for a plate to be poured, inoculated, and colonized. Ours are produced on a rolling schedule and held in inventory fully colonized. Multi-item orders may take an additional 1–2 business days so we can pack everything together.
Why do you use polypropylene plates instead of polystyrene?
Polypropylene flexes under impact instead of cracking. A cracked plate isn't just damaged — it's a contamination risk, since the crack breaks the parafilm seal and exposes the culture. Our Lion's Mane plates are the one exception: they use clear polystyrene for maximum contrast against black agar.
How long will the plate stay viable?
An unopened, parafilm-sealed plate stored at 55–70°F in a dark place stays viable for 60–90 days. Refrigerated at 35–40°F, it stays viable for 6–9 months. King Trumpet handles cold storage well and recovers quickly once brought back to room temperature.
What if my plate arrives contaminated or damaged?
We guarantee every plate ships in clean, fully colonized condition. If you receive a contaminated or damaged plate, contact us within 5 days of delivery with a photo and we'll replace it free of charge.
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