In a candle jar, the thing least spoken of is the thing that decides the most. The wax you can see, the scent you can smell, while the wick is only a small head rising above the wax. And yet if the wick is wrong, everything else goes crooked with it.
We use a cotton wick, with no other core. Cotton fibres are braided into a channel, and its work is very specific: to bring liquid wax up from the melt pool to where the flame is. The flame you see is actually wax burning, not yet the wick burning, and this is the part many people find surprising on first hearing.
Why the thickness of the wick must match the cup
Each cup diameter needs its own wick size. If the wick is thinner than needed, the melt pool never reaches the wall, and after a few burns a rim of wax is left clinging around it. If the wick is thicker than needed, the flame is tall, the wax burns fast, and the tip of the wick easily gives off soot that settles on the wall of the cup.
So before settling a new cup model, we test several wick sizes in the same jar of wax and sit watching them burn through several rounds. What we look for is a small, steady flame, and a melt pool that reaches exactly to the wall after about two hours. There is no shortcut to this, only lighting and watching.
The position of the wick matters as much as its thickness. The wick has to stand right in the middle of the cup, because half a centimetre off and one side of the wall takes more heat than the other, and that jar will burn lopsided for its whole life. In the workshop, setting the wicks straight is one of the first jobs of the morning, done by hand, one at a time.
Five millimetres, the number worth remembering
When a candle jar reaches you, the wick has already been trimmed to the right height for the first lighting, so you can open the lid and light it. From the second time on, trim the wick to about five millimetres before each lighting. This is an easy number to remember and it solves nearly everything that commonly comes up.
A neat wick gives a small, even flame that burns clean with little soot, so the wall of the cup stays clear and the scent comes up steadily through the whole burn. A long wick gives a tall flame; the tip of the wick curls down and gives off smoke, and that is when you see grey marks settling on the wall. If those marks are already there, just wait for the cup to cool, wipe it with a slightly damp paper towel, then trim the wick again and it is done.
And if the wick goes out mid-burn, most of the time it is because it is drowning in the melt pool. Blow it out, let it cool, pour a little of the liquid wax off into a paper box, and once the wax sets the tip of the wick comes clear and you can light it again as normal.
A few questions you often send us
What is the ZUNGZA candle wick made of
A cotton wick, with no other core. We choose the wick size for each cup diameter so the flame stands steady and the melt pool reaches exactly to the wall.
How long should I trim the wick
About five millimetres, trimmed before each lighting. At that height the flame is small, even and clean.
Why does my candle smoke
Usually because the wick is longer than it needs to be, or the candle is standing somewhere a draught catches it. Trim the wick to five millimetres and move it somewhere with less draught, and the flame will settle again.
Read more the story of black marks on the wall of the cup, how to correct a candle burning lopsided, and what goes into a candle jar.