Beaker (100 ml, tall form), glass rod.
Concentrated sulfuric acid (C), sucrose (table sugar).
Fill a beaker two-thirds full with sucrose and place it on an acid-proof surface. Add 4 ml of water to it to accelerate the reaction. Now pour about 25 ml of concentrated sulfuric acid (C) evenly onto the sugar and wait a while. Stirring is not necessary.
Eventually, the whole thing starts to steam and starts to char.
If necessary, support the charcoal sausage with a glass rod.