Article Title: Understanding the Difference Between Substrates
Article link: https://learn.freshcap.com/growing/understanding-mushrooms-substrates/
Author: Tony Schields
Publication: Freshcap
Finding the perfect mushroom substrate for your grow and getting the right substrate recipe is one of the most important aspects of growing mushrooms.
New growers will quickly realize that growing mushrooms is significantly different from growing plants.
Although the concept of a mushroom substrate may be somewhat analogous to that of soil for a plant, the way in which mushrooms actually use a substrate is different and must be fully understood by the grower for the best results.
COMMON MUSHROOM SUBSTRATES
STRAW
Pasteurized straw is commonly used to grow oyster mushrooms. It is cheap and effective, although slightly messy.
HARDWOOD SAWDUST
Hardwoods such as oak, beech and maple make an excellent substrate for many types of mushrooms, especially when combined with a bran supplement.
SOYBALLS
Soybean hulls can be mixed with hardwood sawdust at different ratios to produce extremely effective, high-yielding substrates, especially for growing oyster mushrooms.
MANURE
Common button mushrooms are grown on composted manure, specially prepared using a two-phase composting and sterilization process.
COCONUT COIR AND VERMICULITE
Coco coir is a commercially available mixture of crushed coconut husks and shells, which can be mixed with vermiculite to create an effective substrate.
COFFEE GROUNDS AND ORGANIC WASTE
Mushrooms grow on a number of urban and agricultural wastes, from coffee grounds to banana leaves.
The mushroom substrate must be properly prepared by adding water, possibly adding additional nutrition, and then processing it by sterilization or pasteurization. When ready, it can be "inoculated", where pieces of mycelium-covered mushroom seeds, also called spawn, are mixed evenly into the substrate.
Under the right conditions, the mycelium will begin to grow, quickly devouring and breaking down the organic material in a process called "colonization."
The mushrooms are ready to fruit once the substrate is fully colonized, that is, it has been completely consolidated and encompassed by the mycelium.
PASTEURIZATION OR STERILIZATION OF THE SUBSTRATE
Ideal mushroom substrates are moist and nutrient-rich. Unfortunately, many other things also thrive in these conditions, such as mold and bacteria. These contaminants can grow much faster than mushroom mycelium, so something needs to be done to give the fungi an advantage in the race to colonize the substrate.
This can be accomplished through the process of sterilization or pasteurization.
Pasteurization is the process of heating a substrate between 66 and 83 degrees C for a period of 1.5 to 2 hours. This will not remove all contaminants, but will reduce the overall population of other microorganisms to a level that gives fungal species a head start.
Some microorganisms will survive pasteurization and remain in the substrate in some way, but may actually be useful for long-term mushroom growth.
PASTEURIZATION:
The process of heating a bulk substrate to between 66 and 83 degrees C with steam or in a hot water bath in order to reduce the overall level of contaminations and give mushroom cultivation a good start.
STERILIZATION;
The process of heating the substrate to extreme temperatures in excess of 121 degrees C, under pressure, with the aim of completely removing all living or dormant contaminants in the substrate.