Frosting is a byproduct of a natural wax, and is caused by the growth of tiny crystals on the surfaces of the wax. All soy wax will frost over time, but luckily frosting is solely an aesthetic issue and does not affect the way your candle burns or smells.
Mix melted wax less vigorously
Over-agitating melted soy wax can increase and/or speed up the crystallization process, which produces the frosting appearance.
Preheat your glassware
Preheating your glassware can help reduce the rate of, and extent that, your soy wax candles may frost. You can easily preheat your glassware in a warm oven on the lowest setting. Be sure not to heat your containers over 38°C, and make sure to use caution when handling warm containers.
Pour at a lower temperature
Pouring at a lower temperature can help reduce the crystal formations that form once the wax hardens. Begin adjusting your pour temperature in increments of 5°C.
Let your poured candles cool more slowly
Make sure your candles cool at room temperature (21-25°C is ideal) in a space that is free from drafts. Placing your candles on a wire cooling rack can also help the candle cool evenly, and avoids additional heat transfer that can occur if the candles cool on a solid counter or tabletop.
