Candle tunneling occurs when only a portion of your candle burns down during each lighting, creating a deep well or “tunnel” that’s surrounded by hard rings of unmelted wax. This can affect the overall scent experience of your candle and cause your wick to get buried or lost in the wax as you light it again and again. Tunneling is often the result of a first lighting that is too short, but can also occur due to a wrong-sized wick, poor design, or other factors outside of your control.
Fortunately, there are several different ways to fix your tunneling candles and ensure that they continue burning evenly. The best method involves using an external heat source (like a heat gun or hair dryer on the low blow setting) to melt and level the top surface of the candle. This technique works by resetting the wax memory of your candle and expanding the melt pool to the edges of the container, so that the next time you light it, the entire candle is fully melted from the wick to the edge of the jar.
To avoid tunneling in the future, try to burn your candle for at least an hour during its initial burn. This will help to ensure that all of the wax is melted evenly, and that your candle’s wick remains lit throughout its life. You can also create a foil tent around your candle to help it evenly melt during the burn. Just be sure to poke a hole in the foil for your candle’s smoke to escape so it doesn’t extinguish.