If you don't let your candle reach a full wax pool, you will probably see something called "tunneling". This happens when the wax doesn't burn evenly causing the wick to sink while the wax around it rises, eventually forming a tunnel down the middle of the candle. Depending on how big the tunnel is, your candle might not ever melt completely which means you lose out on hours of burn time.
A good rule of thumb to follow is to allow your candle to burn approximately one hour for every one inch of diameter. As an example, our 4oz candles have a 2.5" diameter. That means the ideal amount of time to let it burn would be 2-2.5 hours.
Once you light your candle, don't extinguish the flame until the top layer of wax has melted to the edge of the container; this is called a wax pool. This can take time so it's not recommended to burn a candle unless you know you'll be able to let it form a full wax pool.
Ideally, you want to let the wax melt all the way across the top with every burn. This allows the surface to stay flat and the sides of the container to stay clean.
CAN YOU FIX TUNNELING
The good news is yes! Depending on how big the tunnel, you might still be able to salvage the candle.
- Try using a hair dryer on low to help even out the surface of the candle
- Put your candle in a heated oven (no more than 200 degree) for a few minutes and the wax on the sides should melt.
- Always trim your wick to 1/4" inch before burning. A wick that's bent or too long will contribute to tunneling and a flickering flame, decreasing the hot throw of you candle.