Look out for signs of mould. If you see any environmentally friendly mold, white fuzzy mould, or darkish black places (mildew) on the mushroom, don't try to eat it. Don’t worry if you see blue staining—This is often prevalent in Psilocybe mushrooms and an indicator that the mushrooms contain psilocybin.  https://psychedelicfarmmeds.com/product/one-up-mushroom-milk-chocolate/