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The Philotree

Why Your Candle Is Tunnelling, and How to Fix It

· 2 min read

Close-up of a soy candle's melt pool

Tunnelling is when a candle burns straight down the middle and leaves a thick wall of wax around the sides. It wastes a lot of the candle, weakens the scent and gets worse with every burn. The good news is that it's almost always fixable.

Why it happens

Wax has a memory. Each time you light a candle, the melted pool tends to stop where it stopped last time. If the first burn is short and the wax only melts in a small circle around the wick, every burn after that follows the same small circle, and the candle digs itself a tunnel.

Other things make it worse:

  • Burning for 30 minutes here and there
  • A draught pushing the flame to one side
  • A wick that's drowned in melted wax and struggling to stay lit

How to fix a tunnelling candle

The foil method (works for most candles)

  1. Light the candle.
  2. Wrap a strip of aluminium foil around the top of the jar, leaving a hole in the middle about the size of a coin so the flame gets air.
  3. Let it burn for an hour or two. The foil reflects heat onto the wax at the edges and melts it down.
  4. Check every 20 minutes. When the surface is level, take the foil off carefully. It will be hot.

If the tunnel is very deep

Pour off a little of the melted wax into a paper towel once the candle has been burning for a while, so the wick isn't drowning. Then use the foil method. Never pour wax down a sink.

How to stop it happening again

  • Make the first burn a long one. Two to three hours, until the wax reaches the edge of the jar. This is the single most important habit.
  • Burn for at least an hour each time after that.
  • Trim the wick to about 5 mm before lighting.
  • Keep it out of draughts, including fans and air conditioning.

These habits also help a candle last its full burn time. See how long a soy candle should last.

Does soy wax tunnel more?

Not if the candle is made well. The size of the wick has to match the width of the jar so the melt pool can reach the edges. Every Philotree candle goes through an 8-hour burn test before a batch is approved, partly to check exactly this. You can read about it on The Craft.

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