The melt pool of a candle is the liquid fuel available for the wick.

It is caused by the flame’s heat radiating down into and melting the wax.  Different waxes form melt pools of different temperatures.  It is important to match the wick to the wax to create the ideal melt pool and candle burn.

Never add anything to the candle wax or melt pool.  Adding materials, such as match sticks, oil, or decorative pieces, changes the way the candle burns in unpredictable ways. This may lead to fire hazards.

Never touch hot or molten wax.

NCA_Cotton Wick Burning v2