There is an on-going debate about whether putting candles in the freezer (before using them) is a good idea. The main reason for wanting to put candles in the freezer is the misconceived idea that it will make them burn longer. At first this seems pretty logical since a candle doesn’t get used up until the wax is liquefied and burns. The idea follows that if it is frozen, a candle will take longer to melt because it is cold.
Unfortunately this idea doesn’t work. Not only will your candle not burn longer, but freezing it could cause your candles to crack. I did a test putting votive candles and pillar candles in the freezer. I got out my stop watch and started timing (I already knew they would crack, just not how long it would take). I planned on checking the candles every 15 minutes to see how long it took them to crack. I went to check on them at the first 15 minute mark… the votives and the pillars were already cracked when I opened the freezer door! I don’t mean just 1 small crack either! Check out this picture. There is no way that the pillar candle could be used because if it was lit, the liquid wax would start to drain out the cracked areas in no time at all. The votive candles could still be used since they are meant to be burned in a votive cup which would contain the liquid wax.
I did the same test with 3 different types of taper candles. And after a little over an hour they had still not cracked. I did not do the test with a jar candle but I don’t think that there would be a problem with those cracking either. Our jar candles are made with a lower melt temperature wax which is a littler softer. The softer wax shouldn’t contract enough for it to crack. Even if the wax in the jar did crack, you should still be able to burn the candle since the wax is contained…in a jar. To be safe, just make sure your glass isn’t cracked too. What may happen to a jar candle in the freezer is that the fragrance may be squeezed out of the wax, leaving oil all around the inside of the glass and on top of the candle.
Now, about the candles being frozen and burning longer…The first thing is that when you put a candle in the freezer, if left in long enough, it will get cold all the way to the core. (We are assuming for this part of the debate that the candle made it through the freezing process unscathed.) As soon as you take the candle out of the freezer it will begin to go back to room temperature. The outside of the candle will warm faster than the inside of the candle. I think that what most supporters (of a frozen candle burning longer) forget, is that when you light a candle you are only heating/melting a small portion of the outside of the candle. The flame is not pulling wax from the colder core of the candle. The approximate peak temperature of a candle flame is between 1300 – 1400 degrees C (2500 degrees F) depending on the type of wax/wick being burned. So when the candle is lit, the surface area of the candle around the flame will warm up far above room temperature extremely fast, undoing any effect the freezer may have had on the candle. As the wax melts, it will heat up more and more of the surface of the candle faster than if the candle were just left to sit on a table unlit. By the time you get to burning the “core” of the candle it will have long lost the effect the freezer had on it.
Save your freezer space for important things, like cookie dough ice-cream. If you want to get the cleanest, longest burn out of your candles, trim your wicks before each lighting. Always allow enough time to burn your candles long enough. For pillars, let the “wax pool” get out near the edge; for jars, let the “wax pool” reach the side of the jar. One of the fastest ways to ruin your candle is to light it over and over putting it out too early each time. Follow these two basic rules of thumb and get the most out of your candles.