Where does wax go as a candle burns?

Inspiration

I’m looking at a candle that’s about a quarter of the way burned and I saw how there’s nothing on the glass wall of the candle and there’s no dense layer on the melted layer of wax. I wondered where the wax goes.

My guess before digging in

The wax somehow vaporizes and diffuses throughout the space the candle’s in.

Findings

• When a candle burns, the wax is transformed into carbon dioxide and water vapor, which are released into the air as gases, essentially “disappearing” as the candle burns down; the heat from the flame melts the wax near the wick, which is then drawn up the wick and vaporized, reacting with oxygen in the air to produce these gases and releasing light and heat in the process
• Candle wax—whether soy wax, paraffin wax, beeswax, or another type—is composed of hydrogen and carbon atoms called hydrocarbons. Specifically, they are long-chain hydrocarbons, meaning they take a solid form at room temperature. This solid state allows the wax to be formed into flakes and slabs, and burn relatively slowly when made into a candle.
• The burning process
  • The wax is the candle’s fuel. However, wax cannot burn on its own, even when exposed directly to fire.
  • It needs a lit wick to begin the combustion process.
  • When a candle wick is lit, the flame’s high heat melts the wax at the base of the wick, transforming it into a liquid state.
  • The wick, acting like a straw, draws the liquid wax up into the flame—a process called capillary action.
  • The intense heat of the candle’s flame causes the melted wax in the wick to vaporize, turning it into flammable gas vapor.
  • Reacting with oxygen in the air, the vaporized wax then combusts into a flame, releasing:
    • Energy, in the form of light and heat
    • Trace soot and smoke
    • Carbon dioxide
    • Water particles

This process continues for as long as wax and oxygen are available.

Source: Where Does the Wax Go When a Candle Burns? - CandleScience (opens in a new tab)