Candle tunnelling is when a candle burns down the center, leaving a hollow tunnel while the wax around the edges remains unburned, resulting in an inefficient and uneven burn. However, there's no need to worry! Candle tunnelling can be fixed pretty easily. Here are a few tips: For mild tunnelling, here are a couple of solutions: Scrape away the excess wax using either a spoon, a butter knife, or a spatula (careful not to scratch the concrete surface). You can either toss out the excess wax or re-melt it. Use the lowest setting on your hairdryer until excess wax melts and the surface is level. If you have a candle that has excessive tunnelling, you can try the aluminum foil method to resolve it. This method helps retain heat and encourages the wax to melt evenly and fill in the tunneling areas. Gently wrap a piece of aluminum foil around the container, leaving only a small hole at the top of the candle exposed to allow the heat and smoke to escape. Leave the foil on for 2-3 hours or until the wax has melted evenly. Remove the foil carefully and use caution as the foil will be hot, and allow the candle to burn normally.