When to Add Fragrance Oil to Candle Wax (Temperature Guide)

Three temperatures, three jobs

A candle recipe usually has three temperatures. They are easy to mix up, and wax makers use them differently.

• Melting. Heat until every flake is liquid. Wax makers warn against holding wax too hot for long. One soy data sheet says brief spikes to 90°C (194°F) are fine if the wax is cooled quickly, but hotter or longer heating can discolor it.
• Adding fragrance. The temperature at which the oil goes in and gets stirred through.
• Pouring. The temperature when the wax enters the jar. This mostly shapes the surface and how well the wax grips the glass.

On some products these are three separate numbers. On others, adding fragrance and pouring happen at nearly the same point.

What wax makers publish

Here are real examples. They do not agree, and that is the point: no single number fits every wax.

A third supplier guide also says to add oil at 185°F, and up to 190°F for dense oils, then stir for two minutes. So you will find advice to add oil hot, and advice to add it cool. Two data sheets say that the fragrance goes in at the pour temperature, right before pouring. The sheets do not explain the difference, so do not mix and match. Follow the sheet for the wax you bought.

Does flash point decide the temperature?

Flash point is the temperature at which an oil gives off enough vapor to briefly ignite near an open flame. It is on every safety data sheet. One candle supplier says it does not tell you when a fragrance oil burns off during candle making, and that heating an oil to its flash point does not cause it to vanish. For ordinary fragrance oils in wax, use the wax and oil suppliers’ temperatures, and keep open flames away from concentrated oil.

Essential oils are where advice splits. One supplier says to let the wax cool to about 10°C below the oil’s flash point, and gives 55–65°C (131–149°F) for soy wax. Another says to avoid essential oils whose flash points are under 170°F. If you use essential oils, read each oil’s safety data sheet and test. See essential oils vs fragrance oils.

Gel wax is its own case. A supplier note says gel candles should only use fragrance with a flash point above 77°C (171°F), because the burn pool runs so hot. Never use a soy or paraffin routine for gel.

A repeatable method

1. Read the data sheet for your exact wax. Note its melt, fragrance and pour guidance.
2. Weigh the wax and the oil separately. Work out the oil from the wax weight; see how much fragrance oil to use.
3. Melt the wax fully, stirring as it melts, with a thermometer in it. A digital probe is the easier choice.
4. If you color the wax, add the dye to the fully melted wax first and stir until it is dissolved. See candle dye.
5. At your wax’s fragrance temperature, add the oil. Stir thoroughly. One supplier suggests two minutes, then a short stir again before pouring.
6. Let the wax reach its pour temperature. Pour slowly into a clean, room-temperature jar. Some sheets say preheating the jar to about 45–50°C (113–122°F) helps with adhesion.
7. Write down the temperatures you actually read, not just the ones you aimed for.

Common mistakes

• Measuring oil by volume. Weigh it. See how much fragrance oil to use.
• Guessing the temperature. Put a thermometer in the wax. Suppliers give figures to the degree for a reason.
• Overheating the wax. One listing says to avoid going above 200°F, and one wax maker warns that long periods above 85–90°C can discolor the wax.
• Adding oil before the wax is fully melted. Dye and oil both need liquid wax to mix evenly.
• Stirring too briefly. One supplier suggests about two minutes after the oil goes in.
• Copying one wax’s numbers to another. A recipe for soy is not a recipe for a coconut blend or paraffin.