Nutrients & Substrates

In mycology, mycelium is a network forming the flesh of fungi. For designers we are referring only to the matted, vegetive bodies of commonly cultivated edible mushrooms. A brief list of the these species includes Oysters, Shiitake, Maitake, Reishi, Lion’s Mane, Portobello, and Wine-Caps. These mushroom’s spores are easily obtained and well studied due to the agricultural value. This accessibility is necessary for designers to be able to work with these fungi outside of a laboratory environment. These mushrooms are Saprophytic wood-decomposing fungi. Edible mushrooms are primary decomposers that have developed specific sets of enzymes to break down lignin-cellulose: the structural component of plant cells. Along with lignin-cellulose, fungi require water and oxygen. Of course, there are also specific temperatures at which different species of fungi are best suited.

When growing mycelium, it is important to understand the basic lifecycle of fungi. Fungi begin as spores, which germinate and form into hyphae, the individual threads that knit together to create mycelium. These hyphae start as wispy, individual strands and grow into a large colony, connecting the nutrients of the substrate.

For farmers and designers, starting from spores can is risky. The spores require a sterile environment that is difficult to achieve without a lab. For this reason, many mushroom growers use grain spawn. Grain spawn is stable mycelial colony grown on high nutrient grains that is broken up and spread into a substrate, where it regrows into a larger colony. Grain spawn can be made at home with access to a pressure-cooker, spore syringes, and a still-air box. It can be ordered in bulk from other growers. To see a short list of were to order grain spawn, please consult our Supply List.

In this video, we can watch a time-lapse of this entire process, start from the spores expanding to the grain spawn, then to the substrate, and finally fruiting mushrooms.

In our research we have found that for a low-tech lab focused on growing mycelium, Oyster Mushrooms are the best choice. They are the most forgiving and least expensive species to grow. They have a relatively quick grow time, and expand aggressively. Oyster’s role as a preeminent wood decomposer, makes them especially capable of growing on any substrate with enough lignin and cellulose. When searching for substrates, the most important thing to keep in mind is the amount of lignin and cellulose in the substrate. Most plant biomass contain these two substances, but they vary in content. They are most available in wood, wood by-products, stalks, straw, hulls, and leaves. Wood by-products allows for them to grow on paper products high in pulp content, specifically Newsprint, cardboard, and construction paper. Oyster mushrooms are also capable of growing on various fabrics that contain a high amount of cotton or hemp

When looking for what species of mushroom to grow, it is worth noting that each species has its own unique environmental, temporal, and nutrient needs. This project exclusively used Oyster Mushrooms. However, Reishi has seen a number of interesting applications due to its dense mycelial growth. See our highlighted use-cases for examples.

For more information on the needs of fungi, Mycopedia highly recommends Paul Stamet’s Growing Gourmet and Medicinal Mushrooms. This is the contemporary mushroom grower’s bible and covers the art of growing in great depth. For an entry-level and more practical guide, Stephen Russel’s The Essential Guide to Cultivating Mushrooms, is indispensable. For those more inclined to blog-post and videos, Freshcap Mushroom’s blog is a great starting point for learning about mushroom cultivation.