Learn how to make agar with this easy 123 recipe. I reccomend following along with this instructional video from PhillyGoldenTeacher for your first time making agar.

Blank agar plate

Requirements 📝

Ingredients Tools
Agar Agar Powder Media Bottle (500 ml recommended)
Corn Syrup Condiment Cups or Petri dishes
Potato Flakes Laser Temperature Thermometer
Water Funnel
Food Coloring (optional)  

Formula 🧫

Ratio ⭐️ For 500 ml Media Bottle 🧪
3g potato flakes 12g potato flakes
2g agar agar powder 8g agar agar powder
1g corn syrup 4g corn syrup
1/2 cup water 2 cups water (about 400 ml)

Directions

Measure out the following incredients in a container on a scale. Order does not matter but I recomend:

  1. Potato flakes
  2. Agar agar powder
  3. Corn syrup

Then, add water to a pot and add all of the ingredients. Now mix the ingredients thoroughly, and put the heat on high to bring to a boil.

As soon as the water is boiling, transfer to your media jar and add 3-5 drops of food coloring. Screw on the cap to the bottle leaving a little space so it is not 100% sealed to prevent pressure from building in the bottle and cracking it.

Pressure cook for 30 minutes at 15 PSI.

How to pour agar

Agar has to be poured before it cools down enough to become a solid. It is reccomended to pour between 140-160 degrees F. If you pour too hot you can melt your petri dishes or condiment cups.

Ideally, you should pour agar in front of a laminar flow hood. Another option is to use a still air box. However, for newbies I have had a lot of success in a clean kitchen, with the air off using the oven technique.

Oven Tek

  1. Turn off air/heat in your kitchen to minimize air movement
  2. Clean your working area well
  3. Preheat your oven to 250 degrees F
  4. Set a baking rack to hang over the opening of the oven
  5. Crack oven open so the air rises above the baking rack
  6. Pour agar into cups/petri dishes in the airflow space

Please reference this video for an in depth guide and to replicate the important sterile techniques.