Gifts Today Home Fragrance 2020

Home fragrance Scientist

Testing, testing

Wax Lyrical’s Dr Will Locke, one of the UK’s leading home fragrance scientists, with over 40 years in the business, explains the science behind candles

Q: Dr Will, what’s your role at Wax Lyrical? A: I am research, development and compliance manager. We produce 17 million quality Britishmade products a year across a vast range of candles and reed diffusers. We will have 200 different fragrances across our product range at any one time, with new fragrances and new products being tested all the time, with different ingredients to appeal to different markets around the world. They're all tested by us in our state-ofthe-art, climate-controlled lab.

Q: How do are you a home fragrance expert for Wax Lyrical? A: I am a scientist with a PhD in chemistry from Reading University. Through my work in the home fragrance industry I am also chair of the technical committee for the British Candlemakers Federation and also sit on the equivalent European body, advising on quality and safety.

‘No computer will tell you exactly how a candle will burn, there are too many variables’

Q: What are the factors that affect a candle’s performance? A: Let’s start with the wick. Wick selection can have a major impact on performance, depending on the material used, the length, number of fibres, braiding pattern, and tension put into it. All wicks are designed to curl as they burn. People might think it’s the wick that’s burning but it’s not, it’s actually the wax.

Then there are the air conditions. You probably didn’t know the type of turbulence that can affect an aeroplane on your holiday flight can also affect a candle’s performance in your living room. It’s all down to the similar movement and conflict of hot and cold air. The tip of a candle reaches between 1200 to 1400 degrees centigrade.

The type of container will also be a factor. If a container, or vessel, is tall and thin, and a candle has burned down towards the bottom (advice is to stop a candle burning at the last 0.5cm), then there’s more opportunity for conflict between the

hot air coming from the tip of the flame and the cold air coming from a room within the space of the candle container. This can cause the candle’s flame to flicker more than it usually would and that could lead to a more erratic burn, which can affect the length of the overall burn, and problems such as tunnelling and sooting.

Q: Why is it necessary to carry out this extensive level of testing? A: No computer will tell you exactly how a candle will burn, there are too many variables. Any new fragrance or new container needs to be tested in this way.

Q: What do you monitor during testing? A: Each set of burning candles has a data sheet recording its performance during its burn. We test flame height, tunnelling (where the burn leaves an area of wax within the vessel which resembles a tunnel), carbon deposits, heat and sooting.

We also carry out further testing to simulate how a candle might age, and also how it will keep its characteristics when subjected to different lighting. You wouldn’t want the colour of a candle to change over time once you got it home.

Q: Are Wax Lyrical products tested for their fragrance? A: Yes, but by a different team. We test people to ensure they have the sense of smell required for the selection of fragrances. It’s important we have a number of people doing that as no two people have the same sense of smell. It’s like fingerprints; a sense of smell is unique to each person. We currently have four ‘expert noses’ in the team.

30 Gifts Today