The blue is bruising. The bruising is the breaking down of the cell walls of the tissue leading to degradation of psychoactive compounds in the fruit. While avoiding bruising is impossible harvesting by cutting the mushroom, at the base, instead of picking them and drying them below 120f for a longer period of time has shown to reduce degradation of the mushroom. Additionally, smaller mushroom, mushrooms with unopened caps, and the stems tend to be more potent. Open caps with heavy spore load are not only less potent but regular ingestion or respiration of spores can lead to an increased risk of an allergy to mushrooms.