Mushroom spawn will naturally develop a white (or yellow for Chicken of the Woods), mold-like layer called mycelium. This branching network of threads is the primary body of fungi, the vegetative structure. A good analogy is if a mushroom is like an apple, then mycelium is like an apple tree. Seeing mycelium grow through your bag is normal and indicates healthy mushroom spawn. If your spawn looks green or black, the culture may be contaminated and should be discarded. You can reach out to us for confirmation.
In the following images, you’ll see healthy spawn plugs with different amounts of mushroom culture visible. The first photo shows plugs with minimal mycelial growth. They are completely fine to use and not any less 'potent'. Over time the mycelium will continue to grow and envelop the plugs as seen in the second photograph. This is also normal and doesn't change how the plugs are used, though you may need to break up the plugs within the bag before use to separate them from the mycelial mass. Don't open the bag; simply squeeze it to break up the mycelial mass. The third photo is the same plug bag after it has been broken.
Often, mycelium is broken up in shipping, so it can appear less myceliated. Let it sit for a few days and it should bounce back.
