Carbon foam has some very useful properties: It is an excellent thermal insulator.
The fact that it's made from bread adds "much wow!" to a very simple process.
You could conceivably cover you space rocket in these ablative tiles for re-entry. Because Science! NASA! Outer-space! Clickbait!
Step 1: Weld a Steel Box With a Hole in It
You'll need a container that you can heat the ever living tar out of. Literally, we are going to roast the tar out of bread.
The hole is so hot gas can escape and the box doesn't blow up and kill you.
I made my hole threaded so I could add a bolt and let only a tiny amount of gas out through the threads.
I also purged the box with Argon gas. A redundant step; but, belt and suspenders amirite?
I'd leave a chemistry joke here, but all the good ones argon.
Step 2: Roast the Box With a Propane Torch, or Campfire, Until No More Yellow Flames Are Visible
The yellow flames are hot volatile gasses leaving the box. Once the yellow flames die down, you know your bread has been turned to carbon foam.
Step 3: Much Fun! Experiments! So Enjoyment! Very Hyperbole!
I blast the carbon foam with an oxy/acetylene torch and melt aluminum directly on the tile.
Then I checked with a thermocouple how well the tile was insulating from the torch blast.
I also checked the electrical resistance. It is very high! From my previous tinkering with graphite, it has very low resistance. The difference is in the structure of the carbon! More research required...
I also made a vid of this. I'm told it sucks: