You light a beautiful candle for the first time, leave it burning for twenty minutes, blow it out, and think nothing of it. The next time you light it, the flame burns straight down the centre, carving a narrow channel into the wax while the edges sit perfectly untouched. A thick ring of wax forms around the sides. The wick sinks lower. Eventually, the flame cannot sustain itself and goes out entirely, leaving most of your candle unburned and unusable.

This is tunnelling and it is one of the most common and most preventable candle problems there is. The good news: once you understand why it happens, you will never let it happen again.

What Is Tunnelling?

Tunnelling occurs when a candle burns straight down its centre rather than melting evenly across the entire surface of the wax. The result is a hole or tunnel forming around the wick, surrounded by a ring of solid, unmelted wax that grows thicker with every burn.

Beyond the appearance, tunnelling has real consequences. It dramatically shortens the life of your candle; all that wax around the edges goes to waste because it never gets warm enough to melt. It reduces the scent throw, because a smaller pool of melted wax releases less fragrance into the room. And eventually, as the wick descends deeper into the wax tunnel, the flame can no longer access enough oxygen to sustain itself and simply dies.¹

A tunnelled candle is not necessarily a poor-quality candle. More often, it is a well-made candle that was not burned correctly — and understanding why starts with one fascinating fact about wax.

Wax Has Memory?

This is the concept that changes how you think about candles entirely.

When you first light a candle, the heat of the flame melts the wax near the wick, creating a pool of liquid wax. The size of this wax pool during the first burn is critical because it essentially programs the candle with a memory of how far the wax should melt outward. If the candle is extinguished before a full melt pool is achieved, a memory ring is established.

Wax has a memory and will create a melt pool only as wide as it did the last time it was lit. Previously melted wax is softer and requires less thermal energy to melt again compared to wax that has never been melted. So, if the candle is only burned long enough for a small central pool to form, that softer central wax will always melt first on subsequent burns while the harder outer wax is bypassed.

The tunnel becomes self-reinforcing. Each burn deepens it. The outer wax becomes increasingly unlikely to ever melt. This means no amount of relighting will reset this pattern unless you intervene deliberately.

Why Does Tunnelling Happen?

·       The first burn was cut too short

More often than not, tunnelling is caused by a first lighting that is simply too brief. If a new candle is lit for a short time that does not allow the melted pool of wax to reach the edge of the container, a barrier is created that will remain on subsequent lightings. This is by far the most common cause and the most important to understand.

·       The wick is undersized for the jar

A wick that is too small for the candle's diameter may not generate enough heat to melt the wax evenly across the surface. This is a candle manufacturing issue rather than a user error — a well-made candle should have a wick correctly sized for its vessel. At Kirsche, wick sizing is one of the most carefully considered elements of our candle-making process precisely because of this.

·       Environmental factors

Burning candles near open windows, fans, or air vents causes the flame to lean and melt unevenly. Cold rooms can also make it harder for the wax to reach the edges, particularly in the first burn. Drafts are the enemy of an even melt pool.

·       Burning for too long

While short burns cause tunnelling, very long burns carry their own risks. Most quality candles should not be burned for more than four hours at a time; excessive heat can cause the wax to pool too quickly, produce soot, and in rare cases damage the vessel.

Golden Rule Of Candle Burning

The first burn of a candle is a pivotal moment that establishes the candle's memory and sets the stage for how the candle will burn in all subsequent uses.

The rule is simple: burn for one hour per inch of the candle's diameter on the first use. A candle with a 7cm (roughly 3 inch) diameter needs at least three hours of uninterrupted burning before you extinguish it. The melt pool must reach the edges of the jar completely, wall to wall, before you blow it out.

If a candle doesn't burn to its edges in the first use, it never will. It will continue to burn in the same narrow pattern, creating a tunnel-like effect.

• This is the single most important piece of candle knowledge there is. Treat the first burn as non-negotiable so plan for it, set aside the time, and do not cut it short.

How To Prevent Tunnelling: The Complete Checklist

•  First burn, full pool: burn until the melt pool reaches the edges of the jar completely before extinguishing. For a Kirsche candle, this typically takes two to three hours depending on the diameter
• Trim the wick before every burn: keep the wick trimmed to approximately 5mm before each use. A properly trimmed wick creates an optimal, even flame. A long or mushroomed wick burns hotter and less evenly, contributing to uneven melting and unnecessary soot
• Burn away from drafts: place your candle somewhere still. Open windows, fans, and air conditioning vents all disrupt the flame and cause uneven burning
•  Burn on a flat, level surface: an uneven surface tilts the flame, which melts the wax unevenly
• Allow the candle to cool completely before relighting: relighting a still-warm candle disturbs the wax before it has fully reset
• Do not burn for more than four hours at a time: longer burns overheat the vessel and can compromise the wax structure
• Keep the wax pool clear: remove any wick debris, matches, or foreign material from the wax pool before burning

How To Fix A Tunnelled Candle

If your candle has already developed a tunnel, do not give up on it. There are several reliable methods to salvage it.

Method 1: The foil tent

This is the most widely recommended method for mild to moderate tunnelling.

Wrap the top of the jar in tin foil, covering the entire opening of the vessel but leaving a hole in the centre large enough to keep the wick lit while allowing oxygen to reach the flame. Light the candle and allow it to burn for two hours. The trapped heat will melt the surrounding wax and even out the surface. The foil gets hot; handle it carefully and allow it to cool before adjusting.

Method 2: The hair dryer reset

Use a hair dryer on a low setting to carefully melt the top layer of wax to the edge of the container while the candle is extinguished. This resets the memory of the wax so that on the next burn, the pool of melted wax will reach the container's edge. Hold the dryer far enough back to avoid splattering wax, and use the lowest heat setting.

Method 3: Scoop and reset

For deeper tunnels, carefully scoop out the excess hardened wax surrounding the wick with a spoon until the surface is even or lower than the melted centre. Wipe the spoon clean and dispose of the wax in a bin. Never dispose any wax down the drain as wax solidifies in pipes. Relight the candle and allow it to burn to a full edge-to-edge pool. This manually removes the memory ring and gives the candle a fresh start.

A note of honesty: If a tunnel is severe (more than 3–4cm deep) salvaging it completely may not be possible. In these cases, the remaining wax can be repurposed in a wax warmer, which brings us to an important alternative.

Wax Melts Alternative

Tunnelling is a flame-and-wick problem. Wax melts, which are warmed by a separate heat source rather than burned with a wick, do not tunnel because there is no flame to create an uneven melt pool.

Wax melts often produce a strong initial scent throw because the warmer heats a large surface area of wax without a flame consuming fragrance. For pure scent intensity in a small space, melts can edge ahead of candles. However, for ambiance, control, and the full sensory experience, candles win; the wax and fragrance quality matter more than the format itself.

Wax melts are worth considering if:

• You have young children or pets and prefer no open flame
• You live somewhere with restrictions on naked flames (some rental properties and apartments)
• You want a stronger immediate scent in a smaller room
• You want to switch fragrances frequently without committing to a full candle

A candle remains the better choice if:

• The flickering light and visual warmth of a flame are part of the experience you are looking for
• You are building an evening ritual where the act of lighting a candle is itself meaningful
• You want a sustained, layered scent that develops as it burns rather than an immediate burst
• You are using candles specifically for their aromatherapy properties; the gentle heat of a wax pool releases essential oil compounds more gradually and steadily than a warmer

At Kirsche, we make both because different moments call for different things. Our wax melts carry the same essential oil fragrances as our candles and are a genuinely excellent alternative for the right situation. Of course for the full ritual experience, a well-burned candle remains in a category of its own.

A note on candle quality and tunnelling

It is worth saying clearly: not all tunnelling is the user's fault.

Sometimes tunnelling results from an incorrectly made candle with a wick that is too small for the size of the container. A quality candle maker tests every product extensively before selling it burning multiple samples, checking the melt pool at regular intervals, adjusting the wick size to the vessel because a candle that tunnels regardless of how it is burned is a manufacturing failure, not a user error.

Harder waxes like paraffin are more prone to tunnelling if not burned long enough, while softer waxes like soy are less likely to tunnel. This is one of the reasons Kirsche candles are hand-poured in soy wax; it is more forgiving, burns more evenly, and is more likely to recover from a short first burn than its harder counterparts.

In Summary

Cause	Prevention	Fix
First burn too short	Burn one hour per inch of diameter; always achieve a full melt pool before extinguishing	Foil tent, hair dryer reset, or scoop and relight
Wick too small for jar	Buy from a maker who tests their products	Little can be done; repurpose wax in a warmer
Drafts or uneven surface	Burn in a still room on a flat, stable surface	Fix the environment and reset with a foil tent
Wick not trimmed	Trim to 5mm before every single burn	Trim wick, use foil tent or hair dryer to even surface

 

Sources

1. Harlem Candle Company (2023). Candle Care 101: How to fix and prevent candle tunneling. https://www.harlemcandleco.com/blogs/journal/candle-care-101-how-to-fix-prevent-candle-tunneling
2. Candlelore (2023). Understanding candle memory: an in-depth look. https://candlelore.com/blogs/news/understanding-candle-memory
3. Effing Candle Co. How to fix a tunneling candle. https://effingcandleco.com/blogs/luxury-candle-blog-effing-candle-co/how-to-fix-a-tunneling-candle
4. Prosperity Candle. How to fix candle tunneling and burn your candle evenly. https://www.prosperitycandle.com/blogs/news/how-to-fix-candle-tunneling
5. The Flaming Candle (2026). How to fix candle tunneling: a guide to saving your candles. https://www.theflamingcandle.com/blogs/articles/how-to-fix-candle-tunneling
6. MBur Candle Co (2026). Wax melts vs candles: which gives better scent throw? https://mburcandle.co/blogs/mbur-blog/wax-melts-vs-candles-which-gives-better-scent-throw
7. NUHR Home. What is the best wax for candles? Soy wax and tunnelling. https://nuhrhome.com/blogs/news/what-is-the-best-wax-for-candles