Liquid culture is an increasingly popular way of cultivating mushrooms at home, requiring minimal equipment and no sterilization in a pressure cooker. Furthermore, mycelium grows much faster than spores.
In order to create liquid mushroom culture, an airport jar (also referred to as grain spawn jar) with an injection port on its lid will be required. Mycelial propagation should take place by injecting mycelium directly into this port on its lid.
Ingredients
Liquid cultures are sterile mixtures of water with specific sugars that provide conditions for mycelium to form after being infected by mushroom spores. When made correctly, liquid cultures allow mycelium to easily inoculate substrates.
Karo syrup is an ideal base for liquid cultures, as its easy sterilization makes observing mycelial growth simpler for mycologists. Plus, its small amount of energy allows it to help propagate faster during inoculation processes.
To create liquid cultures, combine all the necessary ingredients in a sterilized jar with a magnetic stir bar and store in the refrigerator or freezer until ready for use. It is important to select a container with an opening designed for opening with a syringe (such as an airport jar) to prevent airborne contaminants from polluting your culture, thus decreasing risk. You can find numerous mushroom liquid culture recipes online or books like The Difco Manual of Microbiological Culture Media.
Preparation
Liquid culture recipes typically come in the form of premade mixes or ingredients to combine and sterilize; instructions should be included on their packaging or can be found in The Difco Manual of Microbiological Culture Media.
Once your medium is prepared, use a large pot or pressure cooker to sterilize your jars. Be mindful not to tighten down their screw tops too tightly as this could result in them shattering during the sterilization process.
Once mixed, add Karo, peptone and light malt extract to a pot and stir thoroughly to ensure all components have been fully dissolved. Transfer this mixture into separate jars with magnetic stir bars inserted for best results.
Reducing waste requires sterilizing the jars with covers and foil before placing them in your pressure cooker for 25 minutes at 15 psi. Afterward, remove them and allow them to cool in an open area while stirring them frequently to avoid clumping and maintain clarity of your solution.
Storage
Mycelium colonized the nutrient solution much more rapidly than on substrate or agar due to its high viability, as well as being frozen for extended periods.
Liquid cultures are an invaluable asset for mushroom growers of all experience levels, providing a quicker method of inoculation – especially with harder-to-source species like Lion’s mane.
When it comes to liquid culture storage, proper care must be taken. Always sterilize both your jar and hands prior to handling it, then agitate twice daily with either magnetic stir bar agitation or by swirling. Finally, store in a dark environment which helps slow the aging process while simultaneously helping prevent contamination. Before using your liquid culture for any purposes whatsoever, take time out from its storage to test some small amount on either an agar plate or piece of spawn bag to make sure it remains viable.
Use
Liquid culture jars are sterilized mixtures of water and various sugars that have been inoculated with mycelium from various fungus strains or spores to quickly colonise grain substrates compared to traditional spores.
Honey water is an easy-to-make recipe that supports fast mycelium growth, while Karo syrup prevents caramelization during sterilization and Brewer’s yeast can provide additional nutrient boost.
Liquid culture jars should be stored in the fridge to remain stable for at least one year. Before use, ensure the jar has cooled to room temperature before sterilizing with a pressure cooker and injecting with a sterile needle into your chosen substrate. Be sure to change out media periodically in order to prevent strain senescence and encourage fresh colonization – this technique is particularly useful when growing oyster mushrooms or lion’s mane mushrooms.