Using Agar in Mushroom Cultivation - Mushrooms Reach Blog

Agar is a type of gelatinous substance and when poured into a petri dish creates a two dimensional surface. It is commonly used as a growth medium in microbiology and mycology, as it provides a supportive surface for the growth of various microorganisms, including bacteria and fungi such as mushrooms. In mushroom cultivation, this growth medium is generally made with agar agar.

Agar is perfect for a number of various tasks when cultivating mushrooms. It can be used to isolate genetics, transfer dirty cultures into clean ones, germinate spores, and preserve cultures over extended periods. Mycelium on agar can be utilized to initiate grain growth, create liquid cultures, or expand onto additional agar.

Mushroom media plates consist of three primary components: water, a nutrient source, and a gelling agent. Furthermore, a stain or dye is often added to enhance contrast when observing wispy mycelium. Additional ingredients may be added to increase nutritional content, provide bacterial antibiotic properties, etc.

Skip to agar recipes (click here).

Process

Typically, the process for creating plates involves preparing the growth medium, sterilizing it, and then pouring it into sterile plates once it has cooled down sufficiently to handle. This is considered the standard method.

However, there is a variation known as “no pour” which involves pouring the medium into plates prior to sterilization. This approach is particularly useful in less-than-perfect environments, such as when working in a still air box, as it helps to minimize the risk of contamination.

There are many different recipes and variations for preparing media plates, but one of the most commonly utilized at home is a light malt agar extract.