The first burn sets the pattern
Wax has a kind of memory. On the first burn, the flame melts a pool of a certain width, and on later burns the pool tends to stop at that same edge. If you blow the candle out after twenty minutes, before the pool reaches the glass, the next burns will dig down inside that small circle instead of spreading out. That is how tunneling starts.
So the first time you light a container candle or a pillar, keep it burning until the melted wax reaches the edge, or very nearly. A common rule of thumb is about one hour for every inch of the candle's width. A 3-inch jar might need about three hours. Plan the first burn for an evening when you will be in the room the whole time.
First burn, first hour
The pool has reached the middle of the jar. Keep the candle lit until the melted wax touches the glass all the way around.
Full melt pool
A shallow pool runs edge to edge. This is the shape to aim for on the first burn and on every burn after it.
Tunneling
Short burns left a well down the middle and a wall of hard wax around it. The wall wastes wax and can drown the wick.
Before each burn
- Trim the wick to about 1/4 inch (shorter for wood wicks). See the wick guide.
- Clear any matches, wick trimmings or debris from the wax.
- Set the candle on a stable, heat-resistant surface, out of drafts from windows, fans and vents.
- Keep it about 12 inches from anything that can catch fire, and out of reach of children and pets.
How long to burn a candle
After the first burn, a session of one to a few hours is typical. Many candle makers suggest stopping after about four hours. Longer sessions let carbon build up on the wick, the flame grows, and the container can get very hot. If you want the candle again later, put it out, let it cool completely, trim the wick and relight it.
How to put a candle out
A snuffer, a small metal cup on a handle, puts out the flame with little smoke and no spatter. Another tidy method is to use a wick dipper to bend the lit wick into the melted wax and straighten it again; this coats the wick for the next lighting. Blowing works, but it can send hot wax over the rim.
Never use water to put out a candle. Water can make hot wax spatter, and it can crack a hot glass jar.
When to stop using a candle
Stop burning a container candle when about 1/2 inch of wax is left, and a pillar when about 2 inches are left. Near the bottom, the flame is close to the base, and the heat can crack the glass or scorch the surface underneath. The leftover wax can go in a wax warmer approved for that use, or you can clean the jar and reuse it; see storage and cleanup.
Trimmed wick
About 1/4 inch of wick gives a steady, teardrop flame with little or no smoke.
Time to stop
About 1/2 inch of wax is left. Stop here, because the base of the jar can get hot enough to crack or scorch what it sits on.
Pillars and tapers
Pillars need a plate or holder wider than the candle, because melted wax can run down the sides. If one side starts to thin, rotate the candle between burns. Tapers need a holder that grips them firmly and keeps them upright; a leaning taper drips and can tip over. Keep both well away from drafts, which make them burn unevenly and drip.