Closed Loop Mushroom Production on 100% Waste Substrate

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2013: $7,623.00
Projected End Date: 12/31/2013
Region: Southern
State: North Carolina
Principal Investigator:
joseph allawos
Asheville Fungi

Information Products

Waste Stream To Protein (Conference/Presentation Material)


  • Miscellaneous: mushrooms


  • Crop Production: municipal wastes
  • Education and Training: demonstration, farmer to farmer, on-farm/ranch research, youth education
  • Energy: energy conservation/efficiency
  • Farm Business Management: whole farm planning, value added
  • Production Systems: organic agriculture
  • Soil Management: organic matter
  • Sustainable Communities: community services, sustainability measures

    Proposal summary:

    A pilot project is necessary to demonstrate that the proper mix of 100 percent waste stream products is an excellent substrate for growing a wide range of edible mushroom varieties, and that the spent mushroom blocks can be composted and used for fertilizer by local vegetable growers. This project would link waste substrate producers (WSP) with mushroom growers and vegetable farmers. Using waste substrates for cultivating mushrooms is a win/win proposition for the WSP, the mushroom grower, the vegetable farmer, and the community at large. For the WSP, it dramatically reduces landfill waste and disposal costs. In exchange for waste substrate, the mushroom grower may also agree to freely advertise the WSP's business on its packaged product. For example, a small sticker saying "grown with coffee grounds from Joe's Coffee Shack" could be applied to packaging before shipment. For the mushroom grower, this proposed system can dramatically decrease the cost of production by eliminating expenses directly associated with purchasing substrate. For the vegetable farmer, this proposed system can provide a source of local, organic fertilizer. For the community at large, this system reduces landfill waste and acts as a prototype for other communities to follow.

    Project objectives from proposal:

    1. OUTREACH AND COLLECTION: We have identified and contacted five local WSP and one local vegetable farm within a 15 mile radius of our facility and they have agreed to participate in this project. The WSP are Clingman Cafe (up to 500 pounds of certified organic spent coffee grounds a month), Smiling Hara Tempeh Company (up to 100 pounds of certified organic soybean waste a month), Bee Tree Sawmill ( up to 500 pounds of hardwood sawdust a month), River Bend Malt House (up to 500 pounds of organic grain waste a month), and French Broad Chocolate Factory (up to 200 pounds of cacao bean waste a month). The vegetable farm is Full Sun Farm. 

    2. DEVELOPMENT OF SUBSTRATE RECIPES: We will develop different formulations of waste substrate and document how they perform with different mushroom species. Our goal will be to develop four different substrate recipes which can be used to grow all ten of our current production strains. Performance will be measured as "biological efficiency", which is the dry substrate to wet mushroom ratio. For example, if 10 pounds of dry substrate produces 10 pounds of mushrooms, that would represent 100% biological efficiency. 

    3. COMPOSTING SPENT BAGS: Spent mushroom bags will be composted at Full Sun Farm, a local organic vegetable farm, and then used as fertilizer for vegetable production. 

    3. COST ANALYSIS: We will compare actual cost of production on waste substrate versus industry standard substrate. The industry standard consists of a mixture of 77 percent hardwood fuel pellets, 20 percent wheat bran, and 3 percent calcium sulfate (gypsum). Actual cost will consist of labor and fuel expenditures associated with moving the substrate from source to site, processing time, innoculation time, and harvest time.

    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.