Close-up of fresh King Oyster mushrooms at a Berlin market showcasing natural textures and tones.

King "Trumpet" Oyster

Pleurotus Eryngii

Meaty Mild Scallop-like Slow Fruiting

High in plant-based protein and dietary fiber

Contains ergothioneine — a powerful longevity antioxidant

Source of natural statins that support cholesterol balance

Rich in B vitamins, potassium, and selenium

About King Oyster

King Oyster mushrooms are the largest and meatiest of the oyster family, prized worldwide for their thick ivory stems and small caramel-colored caps. Native to the Mediterranean and parts of Asia, they're a culinary chameleon, often sliced into "scallops" or torn into shreds that mimic pulled pork. Unlike their faster oyster cousins, King Oysters fruit slowly under cool, dry conditions and demand precise environmental control. The reward is a uniquely dense, flavorful mushroom that stands up to grilling, searing, and braising. At Kansas City Mushroom Co., we grow our King Oysters with strict CO₂ and humidity targets to develop the firm caps and substantial stems that chefs prize.

Flavor & Texture

King Oysters offer a mild, savory, slightly sweet flavor that deepens dramatically when cooked. The texture is what sets them apart — firm, meaty, and almost seafood-like, with a satisfying bite reminiscent of scallops or abalone. Sliced thick and seared, the stems develop a golden crust and tender interior. Torn lengthwise, they shred into fibers that mimic chicken or pulled pork. They hold their shape beautifully through high-heat cooking.

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Overview Growing

Overview

High

Protein

Rich

B Vitamins

Low

Calories

Antioxidant

Heart Healthy

Culinary Uses

Sear thick slices into golden "scallops"
Tear and braise for plant-based pulled pork
Excellent grilled with olive oil, garlic, and herbs
Shines in pasta, ramen broths, and rice bowls

Growing

Growing Conditions

Grows best on supplemented hardwood substrate (oak, beech, or soy-hull blends)
Ideal fruiting temps: 50–62°F (10–17°C)
Humidity needs: 60–65% during fruiting — the lowest of any oyster variety
Requires CO₂ below 500 ppm — the most CO₂-sensitive variety we grow

Harvesting

King Oysters are ready to harvest when the caps have flattened and just begun to curl upward at the edges, before the gills release spores. Stems should be firm and ivory-white throughout. Twist or cut the entire cluster at the base of the block. Refrigerated promptly, fresh King Oysters keep 10–14 days — the longest shelf life of any oyster we grow, making them ideal for restaurant accounts and CSA boxes.

Lifecycle

King Oyster is the slow, deliberate sibling of the oyster family. Colonization takes weeks — substantially longer than Pink or Italian Oysters — as the mycelium works through dense, supplemented substrate. Once the block is fully colonized, a cool, dry environment with very low CO₂ triggers pinning. From there, mushrooms develop slowly, building thick stems and small caramelized caps over 14–21 days. From inoculation to first harvest typically takes 35–50 days, with one to two flushes per block.

Growth Timeline

Inoculation Day 0
Substrate block is inoculated with grain spawn
Colonization 14–21 days
Mycelium fully colonizes the supplemented hardwood block
Pin Initiation 7–14 days
Cool temps and low CO₂ trigger primordia formation through the bag surface
Pinning Stage 3–5 days
Pins emerge and develop into recognizable young mushrooms
Harvest 14–21 days
Stems thicken and caps form — ready when caps begin to flatten