Binchōtan is a type of charcoal that is made in Japan. It's called binchōtan because it was first made in a city called Tanabe. This charcoal is made from oak, chestnut, bamboo, or other types of wood that are heated at very high temperatures for a long time without oxygen.
The way binchōtan is made is like baking a cake. First, you mix the ingredients, but in this case, you mix the wood chips. Then, you put the mixture in a large metal container and heat it. Unlike a cake, you don't want any air to get in while the binchōtan is cooking. This process is called pyrolysis.
When the binchōtan is done cooking, it's very hard and has no smell. It looks like black sticks. This charcoal is great for cooking because it burns for a long time and produces much less smoke than regular charcoal. It's also used in water purifiers, face masks, and other things.
So next time you see someone cooking with black charcoal, they might be using binchōtan. Remember that it was made by heating wood without air, just like baking a cake with no air!