Making Liquid Culture at Home - A Simple Beginners Guide

Creating a liquid culture at home involves cultivating fungi or bacteria in a nutrient-rich liquid medium. Here's a simple guide to making a basic liquid culture for mushroom cultivation:

Materials Needed:

1. Ingredients:
   • Malt extract or liquid malt extract or Kero vanilla flavored corn syrup or honey.
   • Distilled Water
2. Equipment:
   • Pressure cooker or pot for sterilization or microwave.
   • Glass jars with liquid culture lids
   • Stirring utensil (e.g., spoon)
     
   • Rubber gloves
   • Syringe or inoculation loop

Steps:

1. Prepare the Liquid Medium:
   • Rule of thumb is there should be 90% distilled water to less than 10% Malt extract or  liquid malt extract or Kero vanilla flavored corn syrup or honey in the mix. 
     • Distilled water
   • Measure the desired amount of water and bring it to a boil. 
   • Don't fill the 32 ounce wide mouth mason jar up all the way. Fill it up to about 500 ml so you have room for the sweetener and so you can swirl it around daily without splashing the filter.
   • Add malt extract, corn syrup or honey. Stir until dissolved.
   • Boil the mixture for 10-15 minutes to ensure it's sterile.
   • For microwave use place a jar with water and sweetener with a spawn jar lid attached into the microwave and bring to a boil. Pay attention and turn microwave off after it starts to boil so the gas exchange filter is not damaged. Spawn Jar lids will vent the pressure. Never microwave a jar that has a sealed lid with no place to vent as it will explode and may cause serious injury.
   • Let the liquid cool to room temperature.
2. Sterilize Equipment:
   • Place glass jars with liquid culture lids affixed with filter and injection port in a pressure cooker, add enough water so the bottom of the jar touches the water.
   • Sterilize the jars and lids at 15 PSI for 15-20 minutes. Allow them to cool before handling.
   • If using honey or corn syrup and the microwave method there is no need to pressure cook the mixture.
3. Inoculate with Spores or Mycelium:
   • Work in a clean and sterile environment. Consider using a still air box or glovebox.
   • Put on rubber gloves to avoid contamination.
   • Inoculate the cooled liquid medium with spores or a small piece of mycelium from a mushroom culture using a syringe or inoculation loop.
   • Inject the spores or mycelium into the liquid medium, ensuring the needle is submerged.
   • Another alternative to injecting the jars is to add a tablespoon of colonized grain spawn to the jar and swirl to mix up. 
4. Incubate:
   • Seal the jars with either aluminum foil or a breathable lid to allow for gas exchange.
   • Place the jars in a warm, dark place for the mycelium to grow. Incubation temperatures depend on the specific mushroom species but generally range between 75-80°F (24-27°C).
5. Monitor Growth:
   • Check the jars regularly for signs of growth, such as mycelium strands forming.
   • Shake the jars gently to distribute the mycelium and promote even growth.
6. Harvest and Use:
   • Once the liquid culture is fully colonized, it can be used to inoculate other substrates or spawn bags for further mushroom cultivation.
   • Use a sterile syringe to transfer the liquid culture.