Exploring Sustainable Indoor Mushroom Cultivation
My primary objective was simply to become well acquainted with the nuances of indoor mushroom cultivation. Although the subject always struck me as fascinating in past semesters, I shied away from research knowing full well the wide range of technical knowledge needed to attain a comprehensive understanding of each aspect of production. The Sustainable Farming and Food Systems capstone course provided me with the necessary motivation to delve head-on into the field. After feeling sufficiently knowledgeable and ambitious, I wanted to trial a low-tech, low-budget indoor oyster mushroom (Pleurotus ostreatus) production model using locally-sourced substrate and plastic containers (reusable, as opposed to the more standard polyethylene bags) while further developing the TC3 Farm’s extant mushroom cultures, with the ideal outcome being useful data/cultures/strains.
Why oyster mushrooms?
Oyster mushrooms are uniquely hardy, thus ideal for beginners. They are capable of colonizing a plethora of substrates, including worn-out blue jeans! It should be no surprise that they populate nearly every continent. They routinely prey on nematodes detrimental to more common commercial mushroom varieties and are capable of inhibiting pathogenic bacterial growth. The strain I selected is capable of fruiting at 4.5 °C.
Why would anyone want to do this and how does it relate to sustainability?
In recent years, the sustainable mushroom industry has exploded. Producers nationwide frequently find themselves unable to meet the demand. Diversified farmers seeking a quick growing, hardy crop in high demand need look no further. Oyster mushrooms can be grown and harvested in early spring and late fall when other crops are unavailable. Various agricultural by-products (such as spent coffee grounds and fruit peels) destined for the landfill can be used as free mushroom substrate. I used chopped straw (allowing the mushrooms to spent less energy on colonization and more on fruiting) and spent coffee grounds sourced from the Fireside Cafe.
My trial proved fairly successful. After pasteurizing my substrates, mixing them with my spawn (colonized grain) and placing them in plastic totes and five-gallon buckets with pre-drilled ¼” holes, the chopped straw became thoroughly colonized after three weeks of incubation. Unfortunately, all spent coffee grounds became contaminated. Humidity was increased using transparent plastic garbage bags, ultimately resulting in fruiting bodies. Concocting viable potato dextrose agar (nutrients for tissue samples to grow out on) in the Biology lab proved a success. I managed to re-isolate both the spawn I purchased as well as the TC3 Farm’s shiitake and oyster mushroom cultures from old cultures and fruiting bodies. Using a sterilized scalpel, a laminar flow hood, and copious amounts of isopropyl alcohol I managed to cut squares of oyster and shiitake cultures and insert them into autoclaved, moist grain, creating spawn.
- “Growing Gourmet and Medicinal Mushrooms” by Paul Stamets
- “Mycelium Running: How Mushrooms Can Help Save the World” by Paul Stamets
- “Organic Mushroom Farming and Mycoremediation: Simple to Advanced and Experimental Techniques for Indoor and Outdoor Cultivation” by Tradd Cotter