Candles are meant to burn beautifully and evenly, filling a room with light and fragrance. However, things don’t always go according to plan. You might light a candle only to find it burning unevenly, tunneling straight down the middle, or leaving a thick ring of wasted wax along the sides of the jar.

If this sounds familiar, don’t worry! An uneven burn is a common issue that is completely fixable with a few minor adjustments.

What Causes Uneven Burning?

An uneven burn usually comes down to either candle care or a formulation flaw. Identifying the root cause is the first step to a perfect melt pool.

1. Incorrect Wick Size

Using the wrong wick size for your vessel diameter and wax blend is the top culprit behind a bad burn:

• Too Small: The flame lacks the power to melt the wax to the edge, causing tunneling.
• Too Large: The wick burns too hot, creating an unstable melt pool, deep cratering, and excessive soot.

Tip: Always test your wicks! Every unique wax and fragrance oil combination behaves differently, making thorough burn testing essential.

2. Shortened First Burn (The “Memory Burn”)

The very first burn sets the “memory” of a candle. If you extinguish it too soon, the wax will only melt as far out as it did the first time, establishing a tunnel that gets worse with every subsequent light.

• The Golden Rule: Burn your candle for 1 hour per inch of container diameter on its first use to let the liquid wax reach the edges.

3. Drafts and Airflow

Placing candles near open windows, AC vents, or fans forces the flame to flicker and lean. This distributes heat unevenly, causing one side of the jar to melt much faster than the other. Always burn candles in a still, draft-free environment.

4. Neglecting Wick Trimming

If a wick is too long or has a carbon “mushroom” cap left on it, the flame will dance wildly and burn unevenly. Always trim your wick to 1/4 inch before every single burn to maintain a controlled, steady flame.

5. Candle Formulation Issues

Sometimes the issue is baked right into the candle’s recipe:

• High Fragrance Loads: Overloading your wax with too much fragrance oil can destabilize the burn and cause uneven melting.
• Wax Quirks: Natural waxes like soy are highly prone to tunneling if they are poured at the wrong temperature or not allowed to cure properly.

Candles are meant to burn beautifully and evenly, filling your space with light and fragrance. But sometimes, things don’t go quite as planned, you light your candle only to find that it’s burning unevenly, tunnelling down the middle, or forming wax rings along the edge.
If that sounds familiar, don’t worry! Uneven burning is a common issue and, with the right adjustments, completely fixable.

What Causes Uneven Burning?

Uneven burning can be caused by a few different factors, ranging from wick size to candle care. Understanding the root cause is the first step in troubleshooting.

1. Incorrect Wick Size

One of the most common culprits is using the wrong wick for your candle’s diameter and wax type.

• Too small: The flame doesn’t reach the edges, causing tunnelling.
• Too large: The wick burns too hot, leading to uneven melt pools and soot.

Tip: Always test your wick! Each wax and fragrance combination behaves differently, so testing ensures you find the perfect burn.

2. Not Burning Long Enough on First Use

The first burn is crucial for setting the “memory” of your candle. If you extinguish it too soon, it may create a tunnel that worsens over time.

As a rule of thumb, burn your candle for 1 hour per inch of diameter on the first burn to allow the melt pool to reach the edges.

3. Drafts or Airflow

Candles placed near open windows, vents, or fans can burn unevenly because the flame leans to one side. This leads to uneven heat distribution and an unbalanced melt pool.

Try burning your candle in a still, draft-free environment.

4. Uneven Wick Trimming

If the wick isn’t trimmed evenly before lighting, one side of the flame may burn stronger, causing one side of the candle to melt faster.
Always trim your wick to around 5mm (¼ inch) before each burn to maintain an even flame.

5. Candle Composition

Sometimes, the issue lies in the wax or fragrance load. For example:

• Overly high fragrance percentages can cause uneven melting.
• Some waxes (like soy) are more prone to tunnelling if poured too cool or cured incorrectly.