Maintaining Liquid Culture

One of the benefits of using liquid culture to inoculate mycelium cake jars is the ability to create more liquid culture from liquid culture. This preserves your spore syringe for refreshing your Primary and Secondary liquid cultures later. Remember, spore syringes are expensive and potentially risky if you aren't making your own. Liquid culture costs almost nothing but takes a little longer to make from spores initially. Here are the instructions for making liquid culture.

Storing Liquid Culture

According to PF Tek, liquid culture can be kept for longer in a refrigerator, so this is where we suggest you store it once it has reached full mycelium growth. Until then, inoculated liquid culture should be kept in a dark area (closet, opaque tote, etc) and kept at a temperature of 80° F with a heating pad for mycelium growth. According to PF Tek, liquid culture is good for about one month but doesn't specify how much longer the refrigerator extends liquid culture. We're assuming at least two months and will update with more data.

Extending Liquid Culture

You want to always have two liquid cultures growing that are used for mycelium cake inoculation and two liquid cultures stored for more liquid culture production. When you first receive your spore syringe, inoculate three liquid culture jars per strain (one for primary liquid culture, two for mycelium cake inoculation), saving the rest of the spores for later (if kept in the refrigerator they can be good for one year or more). Keep one jar ready as your backup jar for more liquid culture extender.

Label one of the liquid culture jars as Primary, wait until the jar is 3/4 full of mycelium then store in the refrigerator. When you create more liquid cultures for future mycelium cakes, you will use the Primary liquid culture from the refrigerator to inoculate the liquid culture jars. Make sure to date ALL liquid cultures.

Label the extra liquid culture jar as Secondary. Inoculate Secondary liquid culture jar (with primary liquid culture) one month after Primary liquid culture jar is stored in the refrigerator. Once the primary liquid culture is used up, has contamination or has expired, change the secondary liquid culture to primary liquid culture and create another secondary liquid culture with the new primary liquid culture.