"Tunneling" is when a candle burns down the middle of the jar, leaving lots of wax stuck to the side of the jar. Candles often tunnel due to incorrect wick size or type. The Outer Banks Candle Company candles are wicked to burn clear to the edge of the jar. However, tunneling can also be caused by failure to keep your candle lit long enough before you extinguish it. Each time you burn a candle, try to burn it at least until the melted wax reaches the edge of the container. If you must extinguish your candle early, plan to burn it a little longer the next time. This should prevent your candle from tunneling.