How To Make Karo Liquid Culture.

Karo syrup is a popular choice for making liquid culture broth for mushroom cultivation and mycology. It is a thick, sweet syrup that is made from corn syrup and is widely available in many parts of the world. 

The Karo LC recipe produces a clear solution which allows the mycelium to be easily observed while it grows, a feature often sought after by mycologists. 

Karo Liquid Culture tek is easy to sterilize and is a good source of nutrients for mycelium, making it an ideal choice for a LC recipe. 

To ensure purity of the culture before inoculation you will need to sterilize it, so if you don't have a pressure cooker checkout my post on the best pressure cookers for mushroom cultivation.

Whether you are an experienced mycologist or just getting started in the field, this recipe is a simple and effective way to cultivate a wide variety of mycelium in the laboratory or at home.

In this guide, we'll walk you through the ingredients and materials needed, as well as step-by-step instructions for making Karo Liquid Culture.

Karo Liquid Culture Recipe

The recipe for KARO liquid culture generally consists of a 4% ratio of karo-to-water.

A teaspoon of Karo weighs around 4 grams, so it is possible to do 1 teaspoon per 100ml of water.

However, it is always best to use a scale to accurately measure ingredients whenever possible.

The Karo LC recipe is outlined in the table below: 

Water	Karo	Ratio (% Karo)
100ml	4g	4%
200ml	8g	4%
300ml	12g	4%
400ml	16g	4%
500ml	20g	4%

Step-By-Step Instructions For Making Karo Liquid Culture.

The basic steps are outlined below:

1. Mix 4% Karo into hot water and stir.
2. Sterilize the Karo/Water mixture in a jar
3. Inoculate jar of mixture with mycelium
4. Wait for the mycelium to grow.

Ingredients and Materials Needed:

Checkout this shopping list on our recommended equipment section.

• Karo syrup.
• Pressure cooker (checkout the best pressure cookers for mushroom cultivation).
• Micropore tape or Gas Exchange lids.

Step 1 – Create Karo / Water Mixture.

• I measure out the desired amount of Karo and water. For every 100ml of water, you will need 4g of Karo. I will be using 16g of Karo and 400ml of water.
• Mix the Karo and water together until the Karo is fully dissolved in the mixture.
• Place a stirring rod inside the mixture (optional).
• Place the lid on the jar.
• Create a small hole in the lid using a screwdriver or similar.
• Place two sheets of micropore tape over this hole.
• Wrap the lid in tinfoil and secure with an elastic band.

Step 2 – Sterilize Jars.

• I place my jars into my pressure cooker and sterilize for 30-40 minutes at 15psi. I will be using my presto 23 Qt pressure cooker for this.
• Allow the pressure cooker to cool for several hours before continuing to the next step. I usually leave my cooker overnight just to be sure.

Step 3 – Inoculate Karo/Water Mixture.

• Remove jars from the pressure cooker.
• Wipe the lid of each jar with alcohol wipes.
• Shake the needle to spread out the mycelium.
• Flame sterilize the needle until it is glowing red.
• Inject 1cc of liquid culture into each jar using the flame sterilized needle.
• Cover the injection site with micropore tape, I do this as I'm pulling the needle out.
• Place the jars in an incubation area with a temperature range of 18-20°C (64-68°F) for optimal growth.

Step 4 – Wait.

Generally colonization can take around 14 days.

Place your jar on the stirring plate and wait for it to colonize, if you don't have a stirring plate then just give it a whirl around once a day being careful not to hit the lid.

Result, you can see the colour of the jar changes as nutrients within are consumed. I probably wont be using this jar as there seems to be a dog hair inside, this most likely found its way in before sterilization as the jar looks clean, however its probably not worth using it. 

It has peaked my interest though as the mycelium has completely surrounded the hair and i'm waiting to see if it gets consumed.

Advantages of using Karo for Liquid Culture.

There are several benefits to using Karo syrup as a medium for making liquid culture broth in mycology:

1. Karo syrup is a simple, inexpensive, and readily available source of nutrients for mycelium.
2. It is easy to sterilize and has a long shelf life, making it convenient to use in a laboratory setting.
3. Karo syrup provides a consistent, nutrient-rich environment for the growth of mycelium, which can help improve the success rate of a liquid culture.
4. Karo syrup is also a good source of energy for mycelium, which can help promote healthy growth and reproduction.
5. Karo is a clear liquid which means a mycologist can observe its growth and spot contamination easily.
6. Finally, Karo syrup is less viscous than other types of sugar, making it easier to inject into a jar or petri dish.