The effect of casing and gypsum on the yield and psychoactive tryptamine content of Psilocybe cubensis (Earle) Singer.

Adding a casing layer of peat moss and vermiculite to Psilocybe cubensis mushroom cultivation roughly quadruples biological efficiency (161.5% vs 40.5% without casing), though it slightly delays fruiting by about two days and reduces total tryptamine content to 0.85%. Combining casing with 5% gypsum supplementation yields the highest harvest (896.6 g per kg of dried substrate), a biological efficiency of 89.6%, and maintains high tryptamine levels (0.95%). These findings offer practical guidance for home and commercial growers aiming to maximize both yield and psychoactive compound production.

Study at a glance

Abstract

Psychedelic fungi have experienced a surge in interest in recent years. Most notably, the fungal secondary metabolite psilocybin has shown tremendous promise in the treatment of various psychiatric disorders. The mushroom species that produce this molecule are poorly understood. Here we sought to examine for the first time, the response of a psilocybin-producing species Psilocybe cubensis to casing (peat moss and vermiculite) and supplementation with gypsum (calcium sulfate dihydrate), two common practices in commercial mushroom cultivation. Mycelial samples of genetically authenticated P. cubensis were used to inoculate popcorn grain bags. The fully colonized bags of popcorn grain (0.15 kg) were transferred to bins of 0.85 kg pasteurized horse manure, with or without 1 cm thick layer of casing and/or 5 % gypsum. Our results indicate that the use of a casing layer significantly increases the biological efficiency (161.5 %), by approximately four fold, in comparison to control (40.5 %), albeit with a slight delay (∼2 days) for obtaining fruiting bodies and a somewhat reduced total tryptamine content (0.85 %) as gauged by High Performance Liquid Chromatography measurements. Supplementation with both casing and gypsum, however, appears to promote maximal yields (896.6 g/kg of dried substrate), with a biological efficiency of 89.6 %, while also maintaining high total tryptamine expressions (0.95 %). These findings, revealing methods for maximizing yield of harvest and expressions of psychoactive tryptamines, may prove useful for both home growers and commercial cultivators of this species, and ultimately support the growth of a robust industry with high quality natural products.