system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do candles only make smoke after I blow them out?
gpt
That's not smoke. Its vaporized parrafin wax. It is to wax as steam is to water.

You see, when a candle burns its not the string that is burning, but rather the wax of the candle. Candle wax is quite flammable, but only when vaporized. The melted wax is absorbed by the candle wick, and then burned. When you blow the candle out, for a time the wax in the wick continues to "steam" causing a trail of what appears to be smoke.