"It is something you might bake up at home, if you had a laboratory oven filled with argon gas. It is essentially bread that has been cooked until there is nothing left but a carbon foam.
Just follow the recipe:
Mix up flour, yeast and water, hold the salt, knead, let rise.
Bake for 18 hours at 80°C (~175°) until dry.
Do second bake in laboratory tube furnace filled with argon gas until completely carbonized.
Slice and serve as fireproof rigid insulation, electromagnetic shielding.
Tune and adjust recipe “by changing the amounts of yeast and water, which would allow it to be used for a variety of different applications.”"