Contamination is the bane of every mushroom grower. Knowing how to spot it early can save your entire batch.Common ContaminantsTrichoderma (Green Mold): The most common enemy. It appears as bright green, fuzzy patches and spreads rapidly.Bacillus (Wet Spot): A bacteria that smells sour or foul, making the substrate slimy and dark.Black Mold: Often appears as dark, sooty spots, usually from poor air exchange.When to Toss ItIf you see green, black, or smell anything sour, do not eat the mushrooms. When in doubt, throw it out. The risk of illness is not worth the harvest.