Cornmeal, Sucrose and Yeast Medium
Updated March 30, 2007
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This recipe came from Harvard Biolabs, although they now use a dextrose medium. It has not been used at Bloomington. The cooking instructions assume that your are cooking in a steam-jacketed kettle with an automatic mixer.
The recipe
Water 8.5 liters
Agar 79 grams
Torumel yeast 275 grams
Cornmeal 520 grams
Granulated sugar 1,100 grams
p-Hydroxy-benzoic acid methyl ester 23.8 grams
95% ethanol 91.8 milliliters
*adjust agar concentration according to the gel strength of your agar
Cooking instructions
  1. Boil water.
  2. Add agar, stirring constantly.
  3. After agar has dissolved, add yeast, cornmeal and sugar and continue stirring until mix boils again.
  4. Shut off steam.
  5. Allow the mix to cook with the mixer running for about 15 minutes.
  6. Dissolve p-Hydroxy-benzoic acid methyl ester in ethanol and add to medium; mix thoroughly.
  7. Dispense.
  8. Allow vials to cool for several hours (covered snugly with cheesecloth) before plugging. Allow bottles to sit overnight (covered) before plugging.