| The bluing occurs when phosphatase enzymes are liberated due to cellular damage (cutting bruising). Fresh mushrooms have a fairly low psilocin content (compared to psilocybin) so there is little oxidation untill the psilocybin is dephosphorylated. With proper drying there is little cellular damage and little dephosphorylation. Dried mushrooms can be ground up without bluing because you need an aqueous solvent to allow the enzymes to come into contact with the psilocybin.
I suggest always using some ascorbic acid to prevent oxidation.
-FF |