What is agar?
Agar is a solid media used to culture biological growth. It's commonly used as a base for adding nutrients depending on what you are trying to achieve.
How can I use agar with mushrooms?
Agar can be used in many ways with mushrooms. The most common uses are cloning a mushroom, growing out spores, and inoculating your growing medium or liquid culture. It can also be used for creating hybrids, but that's a whole different topic.
We've compiled a few recipes we've used and had good results with:
- Water Agar
- Spore Starting Agar
- Grain Water Agar
- MEA
- MYA
- Potato Agar
There are many different recipes, but these are the ones people will most commonly reach for.
Supplies needed
- 1 media bottle, Erlenmeyer flask, or canning jar (make sure it can go into a pressure canner)
- A pressure canner
- Petri dishes
- Nitrile gloves
- A Still Air Box (SAB) or a Fan Filter Unit (FFU) / Laminar Flow Hood
- Recommended but optional: Infrared thermometer gun
Process
Combine all ingredients in a pot and bring to a low simmer to dissolve. Once fully dissolved, pour your mixture into your preferred vessel.
Place a lid or aluminum foil on your jar. A modified lid with micropore tape or a Microppose stick-on filter works best. If you have neither, flip the lid over and place the ring on finger tight. This makes it easier to remove when it comes time to pour.
Place your filled containers into the pressure cooker and turn it on. Once steam comes out of the pressure release valve, set a 10 to 15 minute timer. When it goes off, place your 15 psi weight on and set a timer for the recipe time listed below.
Water Agar (WA)
A low-nutrient solution used for cleaning contaminated plates or isolating sectors. Can germinate spores in a pinch, but Spore Starting Agar below is better suited for that.
Ingredients
- 8g Agar
- 500ml Distilled water
Notes
- PC Time: 20 minutes | Yield: ~10 plates
Spore Starting Agar (SSA)
A low-nutrient recipe optimized for germinating spores. The small amount of malt gives germinating spores just enough to work with without encouraging contaminants.
Ingredients
- 5g Agar
- 5g LME
- 500ml Distilled water
Notes
- PC Time: 20 minutes | Yield: ~10 plates
Grain Water Agar (GWA)
A great all-purpose agar that reuses the starchy water left over from boiling your grains. Cheap, easy, and surprisingly effective. The extended PC time accounts for the higher organic content in grain water.
Ingredients
- 10g Agar
- 500ml Grain water (reserved from boiling grains)
Notes
- PC Time: 45 minutes | Yield: ~10 plates
Malt Extract Agar (MEA)
A reliable general-purpose agar, great for transferring spore plates or cloning tissue. The slightly reduced agar produces a softer gel that makes transfers easier.
Ingredients
- 7.5g Agar
- 10g LME (Light Malt Extract)
- 500ml Distilled water
Notes
- PC Time: 30 minutes | Yield: ~10 plates
Malt Yeast Agar (MYA)
A nutrient-rich all-purpose agar. The added yeast gives mycelium an extra boost, making this a good choice for slow or stubborn cultures.
Ingredients
- 7.5g Agar
- 10g LME (Light Malt Extract)
- 1g Yeast
- 500ml Distilled water
Notes
- PC Time: 30 minutes | Yield: ~10 plates
Potato Water Agar (PWA)
A fun option if you have potatoes on hand and nothing else. Not quite as consistent as the malt-based recipes, but it works. Bonus: you get mashed potatoes out of the deal.
Ingredients
- 7.5g Agar
- 200g potatoes, cut into small cubes
- 1500ml water (500ml reserved after boiling)
Steps
- Boil potatoes in water for 1 hour.
- Strain and reserve 500ml of the potato water.
- Stir in 7.5g agar until dissolved.
- Pour into your vessel and PC for 30 minutes.
(Optional but recommended: season and mash the remaining potatoes with salt, pepper, butter, a splash of milk, and garlic powder. Top with chives. Eat immediately.)
Agar Recipe Calculator
Enter your total batch volume or how many plates you want to pour. The other field fills in automatically.
Plate count is adjusted for 10% pouring loss. Actual yield depends on your pour consistency and dish size.
