If you have ever searched for information about selling or gifting candles online, you may have come across advice to perform a burn test on your candles. Burn tests are essential because they help you evaluate the performance of your candles, ensuring that they are safe, efficient and consistent. Although we all understand the importance of burn tests, how to perform them may need to be clarified.
What you'll need:
- A scale;
- A tape measurer;
- A thermometer;
- A writing utensil and paper or a digital method of recording observations;
- Four hours to spare to observe your candle's performance;
- *If burning multiple candles, something with which to label them.
Before making your candle:
To ensure you can recreate a candle precisely as you made it, you'll need to keep track of the formula you used. This includes the vessel, fragrance, wick, and any colourant used. It's essential to use a scale to track the weight of the wax, fragrance, and colourant rather than measuring by volume. This will ensure accuracy and consistency in your future candle-making endeavours once you have verified that the candle is safe. I've included a screen shot of how I track my candle formulas as an example.
Once your candle has cured:
It's time to burn your candle! To ensure its safe use, burning it for a maximum of four hours at a time is recommended. It's important to stay nearby while the candle is burning and get comfortable. Also, consider keeping a fire blanket handy, especially when burning a new candle for the first time. Place your candle on a heat-resistant surface away from drafts, pets, and children. Also, trim the wick to 1/4 inch. Additionally, it's good practice to observe the candle's burning behaviour and record your observations at least every hour. You might also record the first five-minute mark and the first half-hour for better accuracy, as the candle may already fail within the first hour.
Note: if you're burning multiple candles (which I do most of the time), label them (trust me, you may think you'll remember which is which, but it gets confusing).
Things we're looking for while jotting down our observations:
- Container heat: we don't want your candle getting too hot to touch. I used a contactless thermometer to check the outside of the outside of the vessel. Specifically, it's too hot if your thermometer says it is over 60'C/140'F.
- Melt Pool/Tunnelling: The melt pool of the wax should grow by about an inch an hour (e.g. a three-inch vessel should have a complete melt pool in three hours). If the wax is burning too quickly, you are likely over-wicked; if your melt pool is not spreading, you are likely under-wicked, which can lead to tunnelling. This is when the tape measure comes in handy.
- Flame height: if the flame height exceeds 3 inches, the candle fails the test.
- Excessive mushrooming (I caveat excessive because a little mushrooming after four hours isn't an automatic fail for me).
- Has the candle vessel cracked or become damaged in any way?
After burning your candle for four hours, extinguish it and let it cool down entirely before lighting it again. Repeat this process until you have used up the entire candle. If you haven't encountered any of the abovementioned issues, you have done the minimum testing to ensure your candle is enjoyable and safe. However, you may want to test a second candle by not following the burn instructions exactly as some users may do (for example, burning the candle for too long or too short).
