Why does my candle have sinkholes?

What you see: a dip or crater in the surface around the wick after the candle cools, sometimes with a hidden air pocket underneath.

Why it happens: wax shrinks as it cools, and it cools from the outside in. The center is the last part to set, so it pulls down as everything around it contracts. Moving the candle while it's setting, cooling it too fast (cold room, draft, refrigerator), or pouring too hot all make it worse.

The fix: poke relief holes around the wick with a skewer once the surface has set but the center is still soft, then do a second pour — a thin "repour" of the same wax to fill the holes and level the top. Prevention: cool at room temperature, undisturbed, away from drafts. Don't rush it.

Worked example

Pour a soy tin at the top of its window and move it to a cold counter to "set faster," and the outside firms up while the center is still liquid. When that center finally sets it can contract enough to drop a visible crater around the wick — and hide an air pocket under a surface that looked fine. Same wax, same tin, cooled undisturbed at room temperature: flat top. The variable was never the wax. It was the cooling.

Common questions

Why are my soy candles sinking in the middle?
Wax shrinks as it cools, and it cools from the outside in. The walls and bottom set first, the center stays liquid longest, and when the center sets it contracts and pulls down — leaving a sinkhole, sometimes over a hidden air pocket.

How do you fix a sinkhole in a candle?
While the center is still soft, poke a few relief holes around the wick with a skewer to release trapped air, then do a second thin pour of the same wax to fill the holes and level the top.

How do you prevent sinkholes in candles?
Cool at room temperature, undisturbed, away from drafts. Don't move the candle while it sets, don't use a cold room or fridge to speed it up, and don't pour hotter than your wax wants — fast, uneven cooling is the cause.

Is a sinkhole dangerous or just cosmetic?
Mostly cosmetic on the surface, but a hidden air pocket near the wick can make the flame gutter and burn unevenly — which is why the relief-hole fix matters more than just leveling the top.

← Back to the full troubleshooting guide