A comparison of oyster mushrooms focusing on the appearance, growth characteristics, and optimal growing conditions of their colonized substrates:

1. Color of Mycelium

• Blue Oyster Mushrooms (Pleurotus ostreatus):
  The mycelium of blue oyster mushrooms is typically bright white, often forming thick, ropelike strands (rhizomorphs) as it matures.

• Pink Oyster Mushrooms (Pleurotus djamor):
  The mycelium is also white, but as it colonizes, it may develop a slight pinkish hue, especially near the surface where pins (tiny mushroom primordia) start to form.

• Yellow Oyster Mushrooms (Pleurotus citrinopileatus):
  The mycelium of yellow oyster mushrooms is white with a slightly more fluffy appearance. There is no yellowing in the mycelium itself until fruiting bodies form.

• King Oyster Mushrooms (Pleurotus eryngii):
  King oyster mycelium is also white, but typically more dense and compact compared to the other oyster varieties. It has a more uniform and robust appearance.

2. Texture and Density of Mycelium

• Blue Oyster Mushrooms:
  The mycelium is dense and fibrous, often producing thicker rhizomorphs that create a firm, tough appearance as it colonizes the substrate.

• Pink Oyster Mushrooms:
  Pink oyster mycelium is usually softer and more delicate, forming thinner networks. It may not bind the substrate as firmly as blue oysters.

• Yellow Oyster Mushrooms:
  The mycelium is soft and fluffy, often less dense than blue oysters, but it colonizes quickly. It can appear more airy compared to the dense, fibrous networks of blue oysters.

• King Oyster Mushrooms:
  King oyster mycelium is very dense and compact, often forming a tight-knit network that binds the substrate firmly. The mycelium appears robust and is stronger than other oyster varieties.

3. Colonization Speed

• Blue Oyster Mushrooms:
  Moderate colonization speed, typically taking about 2-3 weeks to fully colonize the substrate under optimal conditions.

• Pink Oyster Mushrooms:
  Pink oyster mushrooms have a rapid colonization speed, often taking only 1-2 weeks to fully colonize.

• Yellow Oyster Mushrooms:
  Yellow oyster mushrooms also colonize the substrate quickly, often within 1-2 weeks under ideal conditions.

• King Oyster Mushrooms:
  King oysters take longer to colonize, typically around 3-4 weeks, due to their slower growth rate and more compact mycelium.

4. Temperature Tolerance

• Blue Oyster Mushrooms:
  Thrive in cooler temperatures (60-75°F or 16-24°C), making them ideal for temperate climates.

• Pink Oyster Mushrooms:
  Prefer warmer climates, with an optimal temperature range of 70-85°F (21-29°C), and are much more heat-tolerant.

• Yellow Oyster Mushrooms:
  Favor warmer conditions similar to pink oysters, with an ideal range of 70-80°F (21-27°C). They are more sensitive to colder temperatures.

• King Oyster Mushrooms:
  Prefer cool to moderate temperatures (60-68°F or 16-20°C), closer to blue oysters, and require consistent conditions for optimal growth.

5. Aroma

• Blue Oyster Mushrooms:
  Colonized substrate emits a fresh, earthy mushroom smell typical of most fungi.

• Pink Oyster Mushrooms:
  Slightly sweeter and less intense mushroom odor compared to blue oysters.

• Yellow Oyster Mushrooms:
  Produces a mild, earthy smell, though some report it as having a slightly fruity aroma during colonization.

• King Oyster Mushrooms:
  Have a strong, earthy mushroom smell that is more intense than other oyster varieties due to their dense mycelium.

6. Appearance of Primordia (Pins)

• Blue Oyster Mushrooms:
  The first signs of pinning appear as small, grayish-blue bumps on the surface of the substrate.

• Pink Oyster Mushrooms:
  Bright pink bumps (pins) appear early during colonization, giving the substrate a pink hue.

• Yellow Oyster Mushrooms:
  Primordia are small, yellowish bumps, often forming in clusters as they emerge from the substrate.

• King Oyster Mushrooms:
  Primordia are thicker, white bumps that develop into robust, fleshy fruit bodies. The pins are larger and more distinct compared to other oysters.

7. Fruit Body Characteristics

• Blue Oyster Mushrooms:
  When fruiting, they develop blueish-gray caps that darken as they mature. They grow larger in cooler conditions.

• Pink Oyster Mushrooms:
  Bright pink fruiting bodies that are smaller and more delicate. They fruit quickly and thrive in warm conditions.

• Yellow Oyster Mushrooms:
  Vibrant yellow fruiting bodies that are smaller and more fragile, similar to pink oysters. They form in clustered bouquets and are highly sensitive to environmental changes.

• King Oyster Mushrooms:
  Produce large, thick stems with smaller, tan-colored caps. The fruit bodies are robust and meaty, with significantly thicker stems than other oyster species.

Summary of Differences:

In summary, while all four types of oyster mushrooms share a common growth process, they differ in mycelium appearance, colonization speed, fruit body characteristics, and optimal temperature preferences. King oysters are more robust with slower growth, while pink and yellow oysters are faster-growing and more delicate, and blue oysters thrive in cooler conditions with thicker mycelium.