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How do candles work? Understanding the science behind candles

By Kira Kemlo

5 Min Read

Candles are wonderful for creating a lovely atmosphere with your home fragrances. They’re ideal for cosy evenings, curled up with a good book. Romantic date nights would feel incomplete without the soft flickering dance of candlelight. They’re also amazing gifts for those you love.

Candles are perfect examples of simple, interesting science. They rely on very simple components: a wick, wax and flame. But how do candles work? Let’s take a closer look at some of their intricacies. 

The role of wax

Wax is the unsung hero of candles. It plays a very important role in how they perform. There are various types of wax, such as paraffin, soy and beeswax. Each kind brings different qualities to the candle-making process.

The quality of wax influences how well a candle works. Its burn time, scent and appearance all depend on how good the wax is. Choosing the right wax will take a basic candle and transform it into a delightful, sensory treat. High-quality waxes burn cleanly and evenly, minimising soot and residue. 

Understanding wicks

The primary role of a candle wick is to draw melted wax up to the flame to burn. Wick materials are usually made from cotton or wood. Each one burns a little differently. 

Cotton wicks are the traditional choice. Most of the candles you see in shops will have a cotton wick. They remain popular because they work so well, offering a stable, even burn. A consistent burn means even melting and a steady fragrance.

Wood wicks offer more of a rustic charm. They’re usually made from natural wood and burn with a pleasing little crackle reminiscent of a fireplace, which creates a lovely ambience. They have an even melt pool, due to their wide, flat shape.

The size of the wick also matters. A larger wick produces a bigger flame, which can lead to faster burning and potential soot. Smaller wicks burn slower and more steadily.

To care for your wick and keep your candles burning brightly, make sure to trim it before each use. Use a pair of metal scissors to trim it to about a quarter of an inch, which helps to stop excess smoke and an unsteady burn.

The chemistry behind the candle

Let’s get scientific for a moment. When you light a candle, you set off a captivating play of elements. At the moment of lighting, the heat from the flame melts the surrounding wax. As it melts, the wax turns to liquid and is drawn up through the wick. This process is known as capillary action.

Once the liquid wax reaches the flame, it’s vaporised. At the same time, oxygen from the air combines with the vapourised hydrocarbons of the wax. This results in combustion.

This chemical reaction releases energy in the form of heat and light. It's a reminder of nature's power and elegant chemistry. Ordinary substances to you and me, blend together to light up our world with warmth and radiance.

Things that can affect a candle 

Candles, like us, respond to their environment. External factors can influence their performance.


Can cause the flame to flicker or lean to one side. If the breeze is consistent, it could lead to an uneven melt pool or tunnelling. Make sure you place candles away from any open windows or doorways.


Candles burn faster in warmer conditions due to increased wax flow. Keep candles away from direct sunlight and sources of heat to ensure they stay solid and stable.


High humidity can interfere with scent diffusion. Low humidity might cause candles to dry out. Humidity levels of 40-60% will create a balanced environment for candles to thrive.

Remember to trim your wick before every burn. Place candles on stable surfaces away from flammable materials.

Light up your home with one of our candles

Explore our luxury candle collection and discover scents inspired by our powerfully rugged Scottish isle. We have different sizes available, including mini candles, to suit every room. 

From invigorating notes of lime, grapefruit and green leaf to the comforting embrace of sandalwood, bergamot and sweet cassis, there’s a scent for everyone. Embrace the glow. Whether you're treating yourself or searching for the perfect gift, light up your space with warmth and relaxation.

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