This brief piece is a part of a series on mushroom cultivation. This article details agar and liquid culture mediums, how to best choose one to fit your needs, and provides a few simple recipes for making your own culture mediums.
A mushroom culture is pure mycelium on a growing medium. Mycelium is sort of like the 'roots' of a mushroom. The mycelium colonizes, or 'eats,' the medium it's placed on and using the energy it gathers it produces fruiting bodies (aka mushrooms). The goal of creating a mushroom culture is to create enough mycelium to successfully introduce it to a substrate without it stalling out and dying or becoming contaminated.
Basically, the growing process goes something like this:
Mushroom culture -> Grain Spawn -> Substrate -> Mushrooms
The most important thing to consider in mushroom cultivation is a sterile environment. Indoor grows are especially susceptible to airborne contaminants such as mold and bacteria which compete with and kill mycelium. To make sure you lower the number of potential contaminants it's important to do the following:
A laminar flow hood is ideal for ensuring everything is as sterile as possible, but for a hobby grower buying one or building one isn't worth the cost.
Depending on what your needs are, you may want to either choose to use agar or a liquid culture. I will be outlining the pros and cons of each and which situations they are best for.
Agar is a culture medium for petri dishes that is created using agar-agar powder. It has a firm, jello-like consistency, which functions as a solid media for mycelium to grow on. Once the mycelium has colonized the surface you can easily transfer the culture to other petri dishes by cutting wedges from the agar.
The Pros:
The Cons:
Liquid culture is, as the name states, a liquid culture medium for growing mycelium.
The Pros:
The Cons:
Agar is best for starting a new culture. You can use it to germinate spores, or clone tissue without worrying too much about contamination making it to your spawn. It's incredibly useful for selecting desirable growth as well, allowing you to make transfers from mycelium that shows faster or more aggressive growth. Ultimately, using agar allows for more control.
Liquid culture is for when you finally have a clean culture that you want a lot of. It's best used to inoculate large amounts of spawn because of its fast colonization rate. It's also superior to agar in terms of storage.
To make liquid culture all you need is water and a nutrient. Here I will be using honey as the nutrient. To ensure the culture media is sterile, the liquid culture must be autoclaved or pressure cooked.
Materials Needed:
Ingredients:
Honey and Water in a 1:20 ratio. For example, you would add 5mL (about 1 tsp) of honey to 100mL (About 1/2 cup) of water. It's important to note that you don't have to be exact in the ratio; however, I would keep the honey portion of the ratio below 10%.
Steps:
Making agar requires a bit more effort than liquid culture. You will need a setting agent (agar-agar), a nutrient, and water. In this recipe, I add activated charcoal, which makes it a bit easier to see mycelium growth and also discourages bacteria growth. This ingredient is totally optional, but if you skip it, I recommend adding some food dye to make it easier to see your mycelium growth on your plates. I also weigh out all of the ingredients for this recipe except for the water.
Materials Needed:
Ingredients:
Steps:
* Technically it is possible, but is absolutely not recommended. There's an incredibly high chance that the culture will become contaminated, so it isn't really a viable option. However, if you want to experiment, I recommend using a lc recipe with a really low amount of nutrients.