What is the white mould growing on my mushroom block?


This is called Mycelium. Mycelium is the vegetative part of a fungus or fungus-like bacterial colony, consisting of a mass of branching, thread-like hyphae. This is a good sign that your mushroom block is healthy and is what the mushrooms grow from. It can vary in colour between mushroom types. Some will appear a thick and vivid white while others will be more subtle.

  • Morchella angusticeps mycelium, as it matures turns brown and will start to look like fairy floss on top
  • Hericium coralloides mycelium looks very bare as its a very fine wispy mycelium and is hard to see with the naked eye
  • Lepista nuda mycelium is thicker and will start to grow purple when it matures

All mushroom spawn, if you look closely through a microscope will have a white coating around the grain, some you can see better than others.

All species of fungi and their mycelium are different and shouldn’t be treated the same.

All products we send from our facility are grown and ready to use.