The best way to make sure your essential oils will not evaporate prematurely is to add them at the right moment. That right moment is when the melted wax starts to cool down. It shouldn’t cool down too much though because then the wax will start solidifying and the oils won’t blend.
The ideal temperature to melt the wax is between 122 and 180 degrees Fahrenheit (50 – 80 Celsius). Anything above and the wax will ignite in an instant! So be careful there, because wax is highly flammable.
The best thing about the use of essential oils for soy candle making is that they all have their own flash point. The flash point is the temperature at which a substance can catch fire and burn.
A few degrees over that certain flash point, the flame is able to burn and sustain itself. Each type of essential oil has its own flash point and it’s important to know it for safe candle making.
The flash point of an essential oil must be above the melting temperature of the soy wax, 122 – 180 Fahrenheit (50 – 80 degrees Celsius).
If the oil is added in the candle below its flash point, then its scent will be preserved almost intact. It is always best to choose essential oils with high flash points to make sure their scents stay powerful.
Let’s say your melted wax is 160F. Depending on the oil you use, if its flash point is below 160, you will have to wait for the wax to cool down until it meets that flash point.