When you start off making candles, you can be so excited and but even more impatient. The one thing that should slow you down is that if your making candles, your going to have to provide safety first. Being able to create beautiful candles is one thing but making them safe is extremely important!
"There are industry standards that are referenced from ASTM F 2417-17 Standard Specification for Fire Safety for Candles. This specification is intended to prescribe minimum safety requirements for candles and candle ensembles to provide a reasonable degree of safety for normal use with candles, thereby improving personal safety and reducing fires, deaths, and injuries."
For a long time I never calculated burn time as part of my test burn process for candle making but as a business owner, having enough information to provide to your customers around how long your candles will last is super helpful and provides credibility to your craft. I've actually started to include this now as part of my details in my product briefs on my online store.
I hope this simple but valuable information helps you too!
Step 1
Weigh your finished, unburned candle on a scale. I like to weigh it in ounces but you can also use grams. If it is a container candle, ensure you subtract the weight of the container. This is the original weight of the candle.
Step 2
Now to get a good test burn , you want to light the candle and allow it to burn for four hours. After four hours, blow out the candle and allow it to cool down completely. Next, weigh the candle again, but remember to subtract the weight of the container. This is the post-burn weight.
Step 3
Then, subtract the post-burn weight from the original weight, then divide by the number of hours burned. This number is the hourly burn rate.
Step 4
Lastly your going to want to find the total number of hours the candle will burn, divide the original weight of the candle by the hourly burn
Amount Consumed (Original weight - post-burn weight) ÷ Hours Burnt = Hourly Burn Rate
Original Weight (minus weight of container) ÷ Hourly Burn Rate = Approximate Burn Time
Other factors to consider when testing candles:
Ensure you have the right wick size to the diameter of your container candle. If your flame is "dancing" , then your wick is probably too big for the size of your container. When testing your candle ensure you write down the wick type, and size. Wick performance can also vary even on the on the type of wax used.
Wax pool- this is the amount of wax that melts during the test burn. If your wax pool is not melting to the edge of the container, then your wick may be too small. When your wax pool is too small, you may not be maximizing your scent "throw" - which is the strength of your fragrance and how it fills up the room.
Consider the type of wax you are using to ensure your test burn is completed at the right time.
Natural waxes, like soy, palm or coconut harden over the course of their life as crystals continuously form. They are sensitive to temperature fluctuations, which the leading cost of frosting. These candles should be cured for about 2 weeks before testing.
Most paraffin wax is stable which means they don’t need much time to cure. Burn testing paraffin after 24 hours will yield similar results to a 2 week natural wax.
Ensure you are following the fragrance load reccomendations of the wax you use. Using more than reccomended can impact its performance.
Capture hot & cold throw results by placing test candle in a room with no wind drafts. Hot throw is the scent strength when the candle is burning. Cold throw is the strength of the scent when the candle is sitting without being lit.
Take notes! Capture wick type & performance, container size, cure times, type of wax used, fragrance load, scent throw, and any other details like sink holes, aesthetic appearance, color changes or any additional adjustments you need to make. This will provide any opportunities to check & adjust your approach to making a larger batch or even re-testing.
By now you have enough information to start testing your candles ! Sign up for my community to have quick access to my digital library where I share more tools & resources designed for all my creatives!
I have provided a free download to my checklist to calculate a test burn to help you through ! Good luck and Happy Testing!