Closed Loop Mushroom Production on Waste Substrate

Created with SARE support
2013
SARE products

Asheville Fungi is a mycological supply, sterile lab and grow facility whose goal is to grow edible and medicinal mushrooms on waste substrates that would otherwise end up in landfills. In a SSARE-funded Producer Grant project, the company compared four waste substrates (coffee grounds, cacao shells, soy dust and husks and malt grain fines and beards) to the industry standard of oak fuel pellets, wheat bran and gypsum.

Results of the two-year study found that among the waste stream substrates, cacao shells had the highest average weight harvested per bag at 1.32 pounds and an estimated dry weight biological efficiency of 66 percent during a 90-day harvest period. The soy dust and husk has an average weight harvested per bag of .89 pounds and an estimated dry weight biological efficiency of 44.5 percent, while the spent coffee grounds had an average weight harvested per bag of .81 pounds and an estimated dry weight biological efficiency of 40.5 percent. The crop failed on the malt grain fines and beards.

Compared to the commercial standard, the waste stream substrates fell short. The standard mix had an average weight harvested per at 2.15 pounds and dry weight biological efficiency of 107 percent.

However, a cost analysis comparing the commercial standard to the waste substrates found that the cost to run bags of waste substrate was 59 percent to 73 percent cheaper than the cost to run bags of the commercial formulation.

The waste substrates may provide a more cost-effective alternative for mushroom growers and farmers interested in more sustainable mushroom production practices. The following brochure highlights the research.

Want more information? See the related SARE grant:

This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture through the Sustainable Agriculture Research and Education (SARE) program. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.