Why does my candle only burn in the middle?

Because the first burn was too short. Wax has a memory: the first lighting decides how wide the candle will melt from then on. If the melted layer did not reach the glass that first time, the candle keeps burning inside that same circle and digs a shaft, leaving a thick ledge of hard wax around it. That is tunnelling. A wick left too long, a draught and a habit of short burns all make it worse. It can usually be rescued, and preventing it comes down to three habits that need two tools: a wick trimmer and a snuffer, the two things in our €15 Candle Care Kit.

What tunnelling is

A candle melts outwards from the wick and only then downwards. The flame makes a pool that widens while the candle burns. The moment you put it out, the wax sets at the width it had reached, and next time it starts again from there, because that set line is now the path of least resistance. If the pool never reaches the glass, the shaft gets deeper each time instead of wider. The result is a candle still half full that will not go further.

It costs you wax you paid for, and it costs you scent. Scent comes off the melted surface, so a small pool smells weak in the room whatever the perfume oil. That is also the answer to why some candles are barely noticeable: often the candle is not weak, the melt pool is small.

Four causes

The first burn was too short. By far the most common. A new candle lit for half an hour while you cook, and the shape is set.

The wick is too long. It gives a big, restless flame that burns down faster than it melts outwards, so it digs, and it soots the glass. A charred wick cap does the opposite: the flame stays small and never reaches the edge.

There is a draught on it. An open window, a door that keeps opening, an air vent. The flame gets pushed to one side, so that side melts and the other does not. You spot it by the sloping ledge.

The candle only ever gets lit briefly. A wide jar needs time to open up, and twenty minutes at a time never reaches the edge.

How to rescue a candle that has already tunnelled

Three routes, depending on how deep the tunnel sits. Start with the wick.

The foil collar

For a proper tunnel, a ledge of half a centimetre or more.

1. Trim the wick to about 5 mm.
2. Fold a strip of aluminium foil into a band a few centimetres wide and lay it over the rim like a collar, turned slightly inwards over the hard wax.
3. Leave a generous opening in the middle, at least as wide as the existing pool. The foil must never touch the flame and never cover it.
4. Light the candle and let it burn one to two hours. The foil reflects heat back onto the hard ledge so it melts down with the rest.
5. Lift the foil off with a cloth once the surface is liquid all the way to the glass. It will be hot.

Safety first: never leave a burning candle unattended, keep any single burn to three or four hours, and stop if the glass feels very hot.

One long burn

For an early tunnel of a few millimetres, foil is not needed. Trim the wick, move the candle out of the draught and burn it three to four hours in one go. Do it properly once rather than three times for an hour, because every time you put it out the line sets again.

If the tunnel is too deep for foil

If the wick has sunk so far that the heat no longer reaches the rim, cut some wax away first: cold candle, blunt spoon or blunt knife, thin layers, and no pressure against the glass. Take the hard ledge back until the wick stands at least 5 mm clear, then carry on with the foil collar.

What we do not recommend

The microwave, never: there is usually a metal tab at the base of the wick. The oven we advise against, because a glass jar can crack and you end up with liquid wax in a hot oven. A hairdryer or heat gun blows hot air across liquid wax, which spatters, and the temperature change can crack the glass.

How to prevent it: three habits

Burn to the edge the first time. The only one you cannot catch up on. Let a new candle burn until the whole surface is liquid, out to the glass. The rule of thumb that circulates is roughly one hour per 2.5 cm of jar diameter, but we do not print a diameter on our packaging, so use the figure we do publish: on a 200 g Insphirea candle that first layer is usually liquid after two to three hours. Watch the edge, not the clock.

Trim the wick to about 5 mm before every burn. Not just the first one. Do it when the wax is cold and hard, so the charred tip snaps off cleanly. A short wick gives a steady flame that melts outwards instead of digging down, and it cuts soot.

Snuff it, do not blow it out. Blowing sends smoke and sometimes a spot of hot wax into the air. A snuffer lays the flame down quietly. Keep the candle out of the draught, and stop when about a centimetre of wax is left, so the glass does not overheat.

Two of those three want a tool, and those are the two in the Candle Care Kit: a wick trimmer and a snuffer, €15. The trimmer is curved, so the tip drops into it, not into the wax. Our guide to using the candle care kit covers both, and the full routine is in how to care for your scented candle.

Is it ever the candle's fault?

Sometimes. A wick too thin for its jar will tunnel under perfect handling, and no technique fixes that. Ours are 200 g, around 50 burn hours, 100% natural sunflower wax around a cotton wick, hand-poured in Belgium, €32. The piece on sunflower wax covers the wax, and the candles are on the candle page. Those fifty hours assume a candle that melts to the edge.

Frequently asked questions

Why does my candle only burn in the middle? Because on an earlier burn the melted wax never reached the edge of the glass. Wax remembers that width, so the candle carries on inside the same circle and digs a shaft. Usually the cause is a first burn that was too short, sometimes a wick left too long, sometimes a draught.

Can a candle that has already tunnelled be saved? Usually. Trim the wick to about 5 mm, lay a collar of aluminium foil over the rim of the jar with a generous opening above the flame, and burn it for one to two hours so the heat reflects back onto the hard ledge. Take the foil off once the surface is liquid all the way to the glass. Never leave the candle burning unattended.

How long should the first burn be? Until the whole surface is liquid, out to the glass. On a 200 g Insphirea candle that is usually two to three hours. The rule of thumb of about an hour per 2.5 cm of jar diameter gives a rough idea, but watch the edge, not the clock.

Can I put a scented candle in the oven or the microwave to melt the tunnel out? No. The microwave is out because there is usually a metal tab at the base of the wick, and a glass jar in the oven risks cracked glass and liquid wax in a hot oven. Use the foil collar or one long burn instead.

A candle that only burns in the middle is not a faulty candle, it is a candle that was put out too early once. An evening with a foil collar usually straightens it out, and after that a wick trimmer and a snuffer keep it that way. Delivery to the Netherlands and Belgium is always free.