Description : What Sugar left on the stove too long starts to smoke and turns into a black solid?
Last Answer : Any sugar, if heated, it will begin to melt, and become brownish and toffee-like. If heating continues too long, the toffee-like sugar will begin to burn and eventually leave a black and smouldering ... the bottom pan will help to prevent burning, but still keep an eye on the pans, while stirring.