Hericium erinaceus is a commonly cultivated fungi that has shown promise in recent studies investigating their medicinal effects. Studies have shown the ideal substrate for cultivation of H. erincaceus is a mixture hardwood sawdust and wheat bran. Additionally, certain food waste products have been shown to supplement the substrate mixture effectively. No studies have investigated the effect of spent coffee grounds (SPG) addition the substrate mixture on H. erincaceus cultivation. This study examined the effect of SPG at 0%, 10% and 20% of the substrate mixture by mass. All bags were contaminated and no H. erincaceus was grown. This likely happened because the thermogenic mycelial growth raised the substrate temperature past the optimal growth range, the rye berry inoculation mix was not allowed to grow long enough and the substrate bags were not completely sterilized during autoclaving. These lead to sub-optimal growth of H. erinaceus allowing for it to be out-competed and unable to grow in the substrate bags
