Mushroom Growing

Agar & Media Calculator

Scale a mushroom agar recipe to exactly the number of Petri dishes you're pouring — MEA, PDA, light malt and agar, or a budget honey-and-agar mix — with the grams of each component and the water.

Agar is where you clean up a culture, isolate the fastest-growing mycelium, and store strains. The calculator scales standard per-litre recipes to your dish count, adding a small margin for waste. Sterilize the media at 15 psi for 30–40 minutes, cool it to hand-warm, then pour near a flame or in a still-air box.

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Amounts scale from standard per-litre recipes with ~15% added for waste in the flask and pour. Sterilize the media at 15 psi for 30–40 min, then pour at hand-warm (~50 °C) near a flame or still-air box.

How to use it

  1. Pick a recipe. MEA, PDA from powder, light malt and agar, or honey and agar.
  2. Set dishes and size. How many plates, and whether they're 90 mm or 100 mm.
  3. Read the recipe. Grams of each component and the water to bring it to volume.
  4. Sterilize and pour. 15 psi for 30–40 minutes, cool to hand-warm, pour about 15–20 mL per dish.

Questions

What agar recipe is best for mushrooms?

MEA (malt extract agar) is the reliable all-rounder for most gourmet species. PDA from ready-made powder also gives strong growth.

How much media does a Petri dish need?

About 15 mL for a 90 mm plate and 20 mL for a 100 mm plate. The calculator adds roughly 15% for waste in the flask and pour.

How do I sterilize agar media?

Sterilize the flask at 15 psi for 30–40 minutes, then cool to hand-warm (about 50 °C) before pouring near a flame or in a still-air box.

Can I make agar without malt extract?

Yes — light malt extract from home brewing works, and a honey-and-agar recipe is a pantry alternative.

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